drivers/block/ub.c

   1 /*
   2  * The low performance USB storage driver (ub).
   3  *
   4  * Copyright (c) 1999, 2000 Matthew Dharm (mdharm-usb@one-eyed-alien.net)
   5  * Copyright (C) 2004 Pete Zaitcev (zaitcev@yahoo.com)
   6  *
   7  * This work is a part of Linux kernel, is derived from it,
   8  * and is not licensed separately. See file COPYING for details.
   9  *
  10  * TODO (sorted by decreasing priority)
  11  *  -- Kill first_open (Al Viro fixed the block layer now)
  12  *  -- set readonly flag for CDs, set removable flag for CF readers
  13  *  -- do inquiry and verify we got a disk and not a tape (for LUN mismatch)
  14  *  -- special case some senses, e.g. 3a/0 -> no media present, reduce retries
  15  *  -- verify the 13 conditions and do bulk resets
  16  *  -- kill last_pipe and simply do two-state clearing on both pipes
  17  *  -- verify protocol (bulk) from USB descriptors (maybe...)
  18  *  -- highmem
  19  *  -- move top_sense and work_bcs into separate allocations (if they survive)
  20  *     for cache purists and esoteric architectures.
  21  *  -- Allocate structure for LUN 0 before the first ub_sync_tur, avoid NULL. ?
  22  *  -- prune comments, they are too volumnous
  23  *  -- Exterminate P3 printks
  24  *  -- Resove XXX's
  25  *  -- Redo "benh's retries", perhaps have spin-up code to handle them. V:D=?
  26  *  -- CLEAR, CLR2STS, CLRRS seem to be ripe for refactoring.
  27  */
  28 #include <linux/kernel.h>
  29 #include <linux/module.h>
  30 #include <linux/usb.h>
  31 #include <linux/usb_usual.h>
  32 #include <linux/blkdev.h>
  33 #include <linux/devfs_fs_kernel.h>
  34 #include <linux/timer.h>
  35 #include <scsi/scsi.h>
  36
  37 #define DRV_NAME "ub"
  38 #define DEVFS_NAME DRV_NAME
  39
  40 #define UB_MAJOR 180
  41
  42 /*
  43  * The command state machine is the key model for understanding of this driver.
  44  *
  45  * The general rule is that all transitions are done towards the bottom
  46  * of the diagram, thus preventing any loops.
  47  *
  48  * An exception to that is how the STAT state is handled. A counter allows it
  49  * to be re-entered along the path marked with [C].
  50  *
  51  *       +--------+
  52  *       ! INIT   !
  53  *       +--------+
  54  *           !
  55  *        ub_scsi_cmd_start fails ->--------------------------------------\
  56  *           !                                                            !
  57  *           V                                                            !
  58  *       +--------+                                                       !
  59  *       ! CMD    !                                                       !
  60  *       +--------+                                                       !
  61  *           !                                            +--------+      !
  62  *         was -EPIPE -->-------------------------------->! CLEAR  !      !
  63  *           !                                            +--------+      !
  64  *           !                                                !           !
  65  *         was error -->------------------------------------- ! --------->\
  66  *           !                                                !           !
  67  *  /--<-- cmd->dir == NONE ?                                 !           !
  68  *  !        !                                                !           !
  69  *  !        V                                                !           !
  70  *  !    +--------+                                           !           !
  71  *  !    ! DATA   !                                           !           !
  72  *  !    +--------+                                           !           !
  73  *  !        !                           +---------+          !           !
  74  *  !      was -EPIPE -->--------------->! CLR2STS !          !           !
  75  *  !        !                           +---------+          !           !
  76  *  !        !                                !               !           !
  77  *  !        !                              was error -->---- ! --------->\
  78  *  !      was error -->--------------------- ! ------------- ! --------->\
  79  *  !        !                                !               !           !
  80  *  !        V                                !               !           !
  81  *  \--->+--------+                           !               !           !
  82  *       ! STAT   !<--------------------------/               !           !
  83  *  /--->+--------+                                           !           !
  84  *  !        !                                                !           !
  85  * [C]     was -EPIPE -->-----------\                         !           !
  86  *  !        !                      !                         !           !
  87  *  +<---- len == 0                 !                         !           !
  88  *  !        !                      !                         !           !
  89  *  !      was error -->--------------------------------------!---------->\
  90  *  !        !                      !                         !           !
  91  *  +<---- bad CSW                  !                         !           !
  92  *  +<---- bad tag                  !                         !           !
  93  *  !        !                      V                         !           !
  94  *  !        !                 +--------+                     !           !
  95  *  !        !                 ! CLRRS  !                     !           !
  96  *  !        !                 +--------+                     !           !
  97  *  !        !                      !                         !           !
  98  *  \------- ! --------------------[C]--------\               !           !
  99  *           !                                !               !           !
 100  *         cmd->error---\                +--------+           !           !
 101  *           !          +--------------->! SENSE  !<----------/           !
 102  *         STAT_FAIL----/                +--------+                       !
 103  *           !                                !                           V
 104  *           !                                V                      +--------+
 105  *           \--------------------------------\--------------------->! DONE   !
 106  *                                                                   +--------+
 107  */
 108
 109 /*
 110  * This many LUNs per USB device.
 111  * Every one of them takes a host, see UB_MAX_HOSTS.
 112  */
 113 #define UB_MAX_LUNS   9
 114
 115 /*
 116  */
 117
 118 #define UB_PARTS_PER_LUN      8
 119
 120 #define UB_MAX_CDB_SIZE      16         /* Corresponds to Bulk */
 121
 122 #define UB_SENSE_SIZE  18
 123
 124 /*
 125  */
 126
 127 /* command block wrapper */
 128 struct bulk_cb_wrap {
 129         __le32  Signature;              /* contains 'USBC' */
 130         u32     Tag;                    /* unique per command id */
 131         __le32  DataTransferLength;     /* size of data */
 132         u8      Flags;                  /* direction in bit 0 */
 133         u8      Lun;                    /* LUN */
 134         u8      Length;                 /* of of the CDB */
 135         u8      CDB[UB_MAX_CDB_SIZE];   /* max command */
 136 };
 137
 138 #define US_BULK_CB_WRAP_LEN     31
 139 #define US_BULK_CB_SIGN         0x43425355      /*spells out USBC */
 140 #define US_BULK_FLAG_IN         1
 141 #define US_BULK_FLAG_OUT        0
 142
 143 /* command status wrapper */
 144 struct bulk_cs_wrap {
 145         __le32  Signature;              /* should = 'USBS' */
 146         u32     Tag;                    /* same as original command */
 147         __le32  Residue;                /* amount not transferred */
 148         u8      Status;                 /* see below */
 149 };
 150
 151 #define US_BULK_CS_WRAP_LEN     13
 152 #define US_BULK_CS_SIGN         0x53425355      /* spells out 'USBS' */
 153 #define US_BULK_STAT_OK         0
 154 #define US_BULK_STAT_FAIL       1
 155 #define US_BULK_STAT_PHASE      2
 156
 157 /* bulk-only class specific requests */
 158 #define US_BULK_RESET_REQUEST   0xff
 159 #define US_BULK_GET_MAX_LUN     0xfe
 160
 161 /*
 162  */
 163 struct ub_dev;
 164
 165 #define UB_MAX_REQ_SG   9       /* cdrecord requires 32KB and maybe a header */
 166 #define UB_MAX_SECTORS 64
 167
 168 /*
 169  * A second is more than enough for a 32K transfer (UB_MAX_SECTORS)
 170  * even if a webcam hogs the bus, but some devices need time to spin up.
 171  */
 172 #define UB_URB_TIMEOUT  (HZ*2)
 173 #define UB_DATA_TIMEOUT (HZ*5)  /* ZIP does spin-ups in the data phase */
 174 #define UB_STAT_TIMEOUT (HZ*5)  /* Same spinups and eject for a dataless cmd. */
 175 #define UB_CTRL_TIMEOUT (HZ/2)  /* 500ms ought to be enough to clear a stall */
 176
 177 /*
 178  * An instance of a SCSI command in transit.
 179  */
 180 #define UB_DIR_NONE     0
 181 #define UB_DIR_READ     1
 182 #define UB_DIR_ILLEGAL2 2
 183 #define UB_DIR_WRITE    3
 184
 185 #define UB_DIR_CHAR(c)  (((c)==UB_DIR_WRITE)? 'w': \
 186                          (((c)==UB_DIR_READ)? 'r': 'n'))
 187
 188 enum ub_scsi_cmd_state {
 189         UB_CMDST_INIT,                  /* Initial state */
 190         UB_CMDST_CMD,                   /* Command submitted */
 191         UB_CMDST_DATA,                  /* Data phase */
 192         UB_CMDST_CLR2STS,               /* Clearing before requesting status */
 193         UB_CMDST_STAT,                  /* Status phase */
 194         UB_CMDST_CLEAR,                 /* Clearing a stall (halt, actually) */
 195         UB_CMDST_CLRRS,                 /* Clearing before retrying status */
 196         UB_CMDST_SENSE,                 /* Sending Request Sense */
 197         UB_CMDST_DONE                   /* Final state */
 198 };
 199
 200 static char *ub_scsi_cmd_stname[] = {
 201         ".  ",
 202         "Cmd",
 203         "dat",
 204         "c2s",
 205         "sts",
 206         "clr",
 207         "crs",
 208         "Sen",
 209         "fin"
 210 };
 211
 212 struct ub_scsi_cmd {
 213         unsigned char cdb[UB_MAX_CDB_SIZE];
 214         unsigned char cdb_len;
 215
 216         unsigned char dir;              /* 0 - none, 1 - read, 3 - write. */
 217         unsigned char trace_index;
 218         enum ub_scsi_cmd_state state;
 219         unsigned int tag;
 220         struct ub_scsi_cmd *next;
 221
 222         int error;                      /* Return code - valid upon done */
 223         unsigned int act_len;           /* Return size */
 224         unsigned char key, asc, ascq;   /* May be valid if error==-EIO */
 225
 226         int stat_count;                 /* Retries getting status. */
 227
 228         unsigned int len;               /* Requested length */
 229         unsigned int current_sg;
 230         unsigned int nsg;               /* sgv[nsg] */
 231         struct scatterlist sgv[UB_MAX_REQ_SG];
 232
 233         struct ub_lun *lun;
 234         void (*done)(struct ub_dev *, struct ub_scsi_cmd *);
 235         void *back;
 236 };
 237
 238 struct ub_request {
 239         struct request *rq;
 240         unsigned int current_try;
 241         unsigned int nsg;               /* sgv[nsg] */
 242         struct scatterlist sgv[UB_MAX_REQ_SG];
 243 };
 244
 245 /*
 246  */
 247 struct ub_capacity {
 248         unsigned long nsec;             /* Linux size - 512 byte sectors */
 249         unsigned int bsize;             /* Linux hardsect_size */
 250         unsigned int bshift;            /* Shift between 512 and hard sects */
 251 };
 252
 253 /*
 254  * The SCSI command tracing structure.
 255  */
 256
 257 #define SCMD_ST_HIST_SZ   8
 258 #define SCMD_TRACE_SZ    63             /* Less than 4KB of 61-byte lines */
 259
 260 struct ub_scsi_cmd_trace {
 261         int hcur;
 262         unsigned int tag;
 263         unsigned int req_size, act_size;
 264         unsigned char op;
 265         unsigned char dir;
 266         unsigned char key, asc, ascq;
 267         char st_hst[SCMD_ST_HIST_SZ];
 268 };
 269
 270 struct ub_scsi_trace {
 271         int cur;
 272         struct ub_scsi_cmd_trace vec[SCMD_TRACE_SZ];
 273 };
 274
 275 /*
 276  * This is a direct take-off from linux/include/completion.h
 277  * The difference is that I do not wait on this thing, just poll.
 278  * When I want to wait (ub_probe), I just use the stock completion.
 279  *
 280  * Note that INIT_COMPLETION takes no lock. It is correct. But why
 281  * in the bloody hell that thing takes struct instead of pointer to struct
 282  * is quite beyond me. I just copied it from the stock completion.
 283  */
 284 struct ub_completion {
 285         unsigned int done;
 286         spinlock_t lock;
 287 };
 288
 289 static inline void ub_init_completion(struct ub_completion *x)
 290 {
 291         x->done = 0;
 292         spin_lock_init(&x->lock);
 293 }
 294
 295 #define UB_INIT_COMPLETION(x)   ((x).done = 0)
 296
 297 static void ub_complete(struct ub_completion *x)
 298 {
 299         unsigned long flags;
 300
 301         spin_lock_irqsave(&x->lock, flags);
 302         x->done++;
 303         spin_unlock_irqrestore(&x->lock, flags);
 304 }
 305
 306 static int ub_is_completed(struct ub_completion *x)
 307 {
 308         unsigned long flags;
 309         int ret;
 310
 311         spin_lock_irqsave(&x->lock, flags);
 312         ret = x->done;
 313         spin_unlock_irqrestore(&x->lock, flags);
 314         return ret;
 315 }
 316
 317 /*
 318  */
 319 struct ub_scsi_cmd_queue {
 320         int qlen, qmax;
 321         struct ub_scsi_cmd *head, *tail;
 322 };
 323
 324 /*
 325  * The block device instance (one per LUN).
 326  */
 327 struct ub_lun {
 328         struct ub_dev *udev;
 329         struct list_head link;
 330         struct gendisk *disk;
 331         int id;                         /* Host index */
 332         int num;                        /* LUN number */
 333         char name[16];
 334
 335         int changed;                    /* Media was changed */
 336         int removable;
 337         int readonly;
 338         int first_open;                 /* Kludge. See ub_bd_open. */
 339
 340         struct ub_request urq;
 341
 342         /* Use Ingo's mempool if or when we have more than one command. */
 343         /*
 344          * Currently we never need more than one command for the whole device.
 345          * However, giving every LUN a command is a cheap and automatic way
 346          * to enforce fairness between them.
 347          */
 348         int cmda[1];
 349         struct ub_scsi_cmd cmdv[1];
 350
 351         struct ub_capacity capacity;
 352 };
 353
 354 /*
 355  * The USB device instance.
 356  */
 357 struct ub_dev {
 358         spinlock_t *lock;
 359         atomic_t poison;                /* The USB device is disconnected */
 360         int openc;                      /* protected by ub_lock! */
 361                                         /* kref is too implicit for our taste */
 362         int reset;                      /* Reset is running */
 363         unsigned int tagcnt;
 364         char name[12];
 365         struct usb_device *dev;
 366         struct usb_interface *intf;
 367
 368         struct list_head luns;
 369
 370         unsigned int send_bulk_pipe;    /* cached pipe values */
 371         unsigned int recv_bulk_pipe;
 372         unsigned int send_ctrl_pipe;
 373         unsigned int recv_ctrl_pipe;
 374
 375         struct tasklet_struct tasklet;
 376
 377         struct ub_scsi_cmd_queue cmd_queue;
 378         struct ub_scsi_cmd top_rqs_cmd; /* REQUEST SENSE */
 379         unsigned char top_sense[UB_SENSE_SIZE];
 380
 381         struct ub_completion work_done;
 382         struct urb work_urb;
 383         struct timer_list work_timer;
 384         int last_pipe;                  /* What might need clearing */
 385         __le32 signature;               /* Learned signature */
 386         struct bulk_cb_wrap work_bcb;
 387         struct bulk_cs_wrap work_bcs;
 388         struct usb_ctrlrequest work_cr;
 389
 390         struct work_struct reset_work;
 391         wait_queue_head_t reset_wait;
 392
 393         int sg_stat[6];
 394         struct ub_scsi_trace tr;
 395 };
 396
 397 /*
 398  */
 399 static void ub_cleanup(struct ub_dev *sc);
 400 static int ub_request_fn_1(struct ub_lun *lun, struct request *rq);
 401 static void ub_cmd_build_block(struct ub_dev *sc, struct ub_lun *lun,
 402     struct ub_scsi_cmd *cmd, struct ub_request *urq);
 403 static void ub_cmd_build_packet(struct ub_dev *sc, struct ub_lun *lun,
 404     struct ub_scsi_cmd *cmd, struct ub_request *urq);
 405 static void ub_rw_cmd_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
 406 static void ub_end_rq(struct request *rq, int uptodate);
 407 static int ub_rw_cmd_retry(struct ub_dev *sc, struct ub_lun *lun,
 408     struct ub_request *urq, struct ub_scsi_cmd *cmd);
 409 static int ub_submit_scsi(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
 410 static void ub_urb_complete(struct urb *urb, struct pt_regs *pt);
 411 static void ub_scsi_action(unsigned long _dev);
 412 static void ub_scsi_dispatch(struct ub_dev *sc);
 413 static void ub_scsi_urb_compl(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
 414 static void ub_data_start(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
 415 static void ub_state_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd, int rc);
 416 static int __ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
 417 static void ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
 418 static void ub_state_stat_counted(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
 419 static void ub_state_sense(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
 420 static int ub_submit_clear_stall(struct ub_dev *sc, struct ub_scsi_cmd *cmd,
 421     int stalled_pipe);
 422 static void ub_top_sense_done(struct ub_dev *sc, struct ub_scsi_cmd *scmd);
 423 static void ub_reset_enter(struct ub_dev *sc);
 424 static void ub_reset_task(void *arg);
 425 static int ub_sync_tur(struct ub_dev *sc, struct ub_lun *lun);
 426 static int ub_sync_read_cap(struct ub_dev *sc, struct ub_lun *lun,
 427     struct ub_capacity *ret);
 428 static int ub_probe_lun(struct ub_dev *sc, int lnum);
 429
 430 /*
 431  */
 432 #ifdef CONFIG_USB_LIBUSUAL
 433
 434 #define ub_usb_ids  storage_usb_ids
 435 #else
 436
 437 static struct usb_device_id ub_usb_ids[] = {
 438         { USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, US_SC_SCSI, US_PR_BULK) },
 439         { }
 440 };
 441
 442 MODULE_DEVICE_TABLE(usb, ub_usb_ids);
 443 #endif /* CONFIG_USB_LIBUSUAL */
 444
 445 /*
 446  * Find me a way to identify "next free minor" for add_disk(),
 447  * and the array disappears the next day. However, the number of
 448  * hosts has something to do with the naming and /proc/partitions.
 449  * This has to be thought out in detail before changing.
 450  * If UB_MAX_HOST was 1000, we'd use a bitmap. Or a better data structure.
 451  */
 452 #define UB_MAX_HOSTS  26
 453 static char ub_hostv[UB_MAX_HOSTS];
 454
 455 #define UB_QLOCK_NUM 5
 456 static spinlock_t ub_qlockv[UB_QLOCK_NUM];
 457 static int ub_qlock_next = 0;
 458
 459 static DEFINE_SPINLOCK(ub_lock);        /* Locks globals and ->openc */
 460
 461 /*
 462  * The SCSI command tracing procedures.
 463  */
 464
 465 static void ub_cmdtr_new(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
 466 {
 467         int n;
 468         struct ub_scsi_cmd_trace *t;
 469
 470         if ((n = sc->tr.cur + 1) == SCMD_TRACE_SZ) n = 0;
 471         t = &sc->tr.vec[n];
 472
 473         memset(t, 0, sizeof(struct ub_scsi_cmd_trace));
 474         t->tag = cmd->tag;
 475         t->op = cmd->cdb[0];
 476         t->dir = cmd->dir;
 477         t->req_size = cmd->len;
 478         t->st_hst[0] = cmd->state;
 479
 480         sc->tr.cur = n;
 481         cmd->trace_index = n;
 482 }
 483
 484 static void ub_cmdtr_state(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
 485 {
 486         int n;
 487         struct ub_scsi_cmd_trace *t;
 488
 489         t = &sc->tr.vec[cmd->trace_index];
 490         if (t->tag == cmd->tag) {
 491                 if ((n = t->hcur + 1) == SCMD_ST_HIST_SZ) n = 0;
 492                 t->st_hst[n] = cmd->state;
 493                 t->hcur = n;
 494         }
 495 }
 496
 497 static void ub_cmdtr_act_len(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
 498 {
 499         struct ub_scsi_cmd_trace *t;
 500
 501         t = &sc->tr.vec[cmd->trace_index];
 502         if (t->tag == cmd->tag)
 503                 t->act_size = cmd->act_len;
 504 }
 505
 506 static void ub_cmdtr_sense(struct ub_dev *sc, struct ub_scsi_cmd *cmd,
 507     unsigned char *sense)
 508 {
 509         struct ub_scsi_cmd_trace *t;
 510
 511         t = &sc->tr.vec[cmd->trace_index];
 512         if (t->tag == cmd->tag) {
 513                 t->key = sense[2] & 0x0F;
 514                 t->asc = sense[12];
 515                 t->ascq = sense[13];
 516         }
 517 }
 518
 519 static ssize_t ub_diag_show(struct device *dev, struct device_attribute *attr,
 520     char *page)
 521 {
 522         struct usb_interface *intf;
 523         struct ub_dev *sc;
 524         struct list_head *p;
 525         struct ub_lun *lun;
 526         int cnt;
 527         unsigned long flags;
 528         int nc, nh;
 529         int i, j;
 530         struct ub_scsi_cmd_trace *t;
 531
 532         intf = to_usb_interface(dev);
 533         sc = usb_get_intfdata(intf);
 534         if (sc == NULL)
 535                 return 0;
 536
 537         cnt = 0;
 538         spin_lock_irqsave(sc->lock, flags);
 539
 540         cnt += sprintf(page + cnt,
 541             "poison %d reset %d\n",
 542             atomic_read(&sc->poison), sc->reset);
 543         cnt += sprintf(page + cnt,
 544             "qlen %d qmax %d\n",
 545             sc->cmd_queue.qlen, sc->cmd_queue.qmax);
 546         cnt += sprintf(page + cnt,
 547             "sg %d %d %d %d %d .. %d\n",
 548             sc->sg_stat[0],
 549             sc->sg_stat[1],
 550             sc->sg_stat[2],
 551             sc->sg_stat[3],
 552             sc->sg_stat[4],
 553             sc->sg_stat[5]);
 554
 555         list_for_each (p, &sc->luns) {
 556                 lun = list_entry(p, struct ub_lun, link);
 557                 cnt += sprintf(page + cnt,
 558                     "lun %u changed %d removable %d readonly %d\n",
 559                     lun->num, lun->changed, lun->removable, lun->readonly);
 560         }
 561
 562         if ((nc = sc->tr.cur + 1) == SCMD_TRACE_SZ) nc = 0;
 563         for (j = 0; j < SCMD_TRACE_SZ; j++) {
 564                 t = &sc->tr.vec[nc];
 565
 566                 cnt += sprintf(page + cnt, "%08x %02x", t->tag, t->op);
 567                 if (t->op == REQUEST_SENSE) {
 568                         cnt += sprintf(page + cnt, " [sense %x %02x %02x]",
 569                                         t->key, t->asc, t->ascq);
 570                 } else {
 571                         cnt += sprintf(page + cnt, " %c", UB_DIR_CHAR(t->dir));
 572                         cnt += sprintf(page + cnt, " [%5d %5d]",
 573                                         t->req_size, t->act_size);
 574                 }
 575                 if ((nh = t->hcur + 1) == SCMD_ST_HIST_SZ) nh = 0;
 576                 for (i = 0; i < SCMD_ST_HIST_SZ; i++) {
 577                         cnt += sprintf(page + cnt, " %s",
 578                                         ub_scsi_cmd_stname[(int)t->st_hst[nh]]);
 579                         if (++nh == SCMD_ST_HIST_SZ) nh = 0;
 580                 }
 581                 cnt += sprintf(page + cnt, "\n");
 582
 583                 if (++nc == SCMD_TRACE_SZ) nc = 0;
 584         }
 585
 586         spin_unlock_irqrestore(sc->lock, flags);
 587         return cnt;
 588 }
 589
 590 static DEVICE_ATTR(diag, S_IRUGO, ub_diag_show, NULL); /* N.B. World readable */
 591
 592 /*
 593  * The id allocator.
 594  *
 595  * This also stores the host for indexing by minor, which is somewhat dirty.
 596  */
 597 static int ub_id_get(void)
 598 {
 599         unsigned long flags;
 600         int i;
 601
 602         spin_lock_irqsave(&ub_lock, flags);
 603         for (i = 0; i < UB_MAX_HOSTS; i++) {
 604                 if (ub_hostv[i] == 0) {
 605                         ub_hostv[i] = 1;
 606                         spin_unlock_irqrestore(&ub_lock, flags);
 607                         return i;
 608                 }
 609         }
 610         spin_unlock_irqrestore(&ub_lock, flags);
 611         return -1;
 612 }
 613
 614 static void ub_id_put(int id)
 615 {
 616         unsigned long flags;
 617
 618         if (id < 0 || id >= UB_MAX_HOSTS) {
 619                 printk(KERN_ERR DRV_NAME ": bad host ID %d\n", id);
 620                 return;
 621         }
 622
 623         spin_lock_irqsave(&ub_lock, flags);
 624         if (ub_hostv[id] == 0) {
 625                 spin_unlock_irqrestore(&ub_lock, flags);
 626                 printk(KERN_ERR DRV_NAME ": freeing free host ID %d\n", id);
 627                 return;
 628         }
 629         ub_hostv[id] = 0;
 630         spin_unlock_irqrestore(&ub_lock, flags);
 631 }
 632
 633 /*
 634  * This is necessitated by the fact that blk_cleanup_queue does not
 635  * necesserily destroy the queue. Instead, it may merely decrease q->refcnt.
 636  * Since our blk_init_queue() passes a spinlock common with ub_dev,
 637  * we have life time issues when ub_cleanup frees ub_dev.
 638  */
 639 static spinlock_t *ub_next_lock(void)
 640 {
 641         unsigned long flags;
 642         spinlock_t *ret;
 643
 644         spin_lock_irqsave(&ub_lock, flags);
 645         ret = &ub_qlockv[ub_qlock_next];
 646         ub_qlock_next = (ub_qlock_next + 1) % UB_QLOCK_NUM;
 647         spin_unlock_irqrestore(&ub_lock, flags);
 648         return ret;
 649 }
 650
 651 /*
 652  * Downcount for deallocation. This rides on two assumptions:
 653  *  - once something is poisoned, its refcount cannot grow
 654  *  - opens cannot happen at this time (del_gendisk was done)
 655  * If the above is true, we can drop the lock, which we need for
 656  * blk_cleanup_queue(): the silly thing may attempt to sleep.
 657  * [Actually, it never needs to sleep for us, but it calls might_sleep()]
 658  */
 659 static void ub_put(struct ub_dev *sc)
 660 {
 661         unsigned long flags;
 662
 663         spin_lock_irqsave(&ub_lock, flags);
 664         --sc->openc;
 665         if (sc->openc == 0 && atomic_read(&sc->poison)) {
 666                 spin_unlock_irqrestore(&ub_lock, flags);
 667                 ub_cleanup(sc);
 668         } else {
 669                 spin_unlock_irqrestore(&ub_lock, flags);
 670         }
 671 }
 672
 673 /*
 674  * Final cleanup and deallocation.
 675  */
 676 static void ub_cleanup(struct ub_dev *sc)
 677 {
 678         struct list_head *p;
 679         struct ub_lun *lun;
 680         request_queue_t *q;
 681
 682         while (!list_empty(&sc->luns)) {
 683                 p = sc->luns.next;
 684                 lun = list_entry(p, struct ub_lun, link);
 685                 list_del(p);
 686
 687                 /* I don't think queue can be NULL. But... Stolen from sx8.c */
 688                 if ((q = lun->disk->queue) != NULL)
 689                         blk_cleanup_queue(q);
 690                 /*
 691                  * If we zero disk->private_data BEFORE put_disk, we have
 692                  * to check for NULL all over the place in open, release,
 693                  * check_media and revalidate, because the block level
 694                  * semaphore is well inside the put_disk.
 695                  * But we cannot zero after the call, because *disk is gone.
 696                  * The sd.c is blatantly racy in this area.
 697                  */
 698                 /* disk->private_data = NULL; */
 699                 put_disk(lun->disk);
 700                 lun->disk = NULL;
 701
 702                 ub_id_put(lun->id);
 703                 kfree(lun);
 704         }
 705
 706         kfree(sc);
 707 }
 708
 709 /*
 710  * The "command allocator".
 711  */
 712 static struct ub_scsi_cmd *ub_get_cmd(struct ub_lun *lun)
 713 {
 714         struct ub_scsi_cmd *ret;
 715
 716         if (lun->cmda[0])
 717                 return NULL;
 718         ret = &lun->cmdv[0];
 719         lun->cmda[0] = 1;
 720         return ret;
 721 }
 722
 723 static void ub_put_cmd(struct ub_lun *lun, struct ub_scsi_cmd *cmd)
 724 {
 725         if (cmd != &lun->cmdv[0]) {
 726                 printk(KERN_WARNING "%s: releasing a foreign cmd %p\n",
 727                     lun->name, cmd);
 728                 return;
 729         }
 730         if (!lun->cmda[0]) {
 731                 printk(KERN_WARNING "%s: releasing a free cmd\n", lun->name);
 732                 return;
 733         }
 734         lun->cmda[0] = 0;
 735 }
 736
 737 /*
 738  * The command queue.
 739  */
 740 static void ub_cmdq_add(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
 741 {
 742         struct ub_scsi_cmd_queue *t = &sc->cmd_queue;
 743
 744         if (t->qlen++ == 0) {
 745                 t->head = cmd;
 746                 t->tail = cmd;
 747         } else {
 748                 t->tail->next = cmd;
 749                 t->tail = cmd;
 750         }
 751
 752         if (t->qlen > t->qmax)
 753                 t->qmax = t->qlen;
 754 }
 755
 756 static void ub_cmdq_insert(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
 757 {
 758         struct ub_scsi_cmd_queue *t = &sc->cmd_queue;
 759
 760         if (t->qlen++ == 0) {
 761                 t->head = cmd;
 762                 t->tail = cmd;
 763         } else {
 764                 cmd->next = t->head;
 765                 t->head = cmd;
 766         }
 767
 768         if (t->qlen > t->qmax)
 769                 t->qmax = t->qlen;
 770 }
 771
 772 static struct ub_scsi_cmd *ub_cmdq_pop(struct ub_dev *sc)
 773 {
 774         struct ub_scsi_cmd_queue *t = &sc->cmd_queue;
 775         struct ub_scsi_cmd *cmd;
 776
 777         if (t->qlen == 0)
 778                 return NULL;
 779         if (--t->qlen == 0)
 780                 t->tail = NULL;
 781         cmd = t->head;
 782         t->head = cmd->next;
 783         cmd->next = NULL;
 784         return cmd;
 785 }
 786
 787 #define ub_cmdq_peek(sc)  ((sc)->cmd_queue.head)
 788
 789 /*
 790  * The request function is our main entry point
 791  */
 792
 793 static void ub_request_fn(request_queue_t *q)
 794 {
 795         struct ub_lun *lun = q->queuedata;
 796         struct request *rq;
 797
 798         while ((rq = elv_next_request(q)) != NULL) {
 799                 if (ub_request_fn_1(lun, rq) != 0) {
 800                         blk_stop_queue(q);
 801                         break;
 802                 }
 803         }
 804 }
 805
 806 static int ub_request_fn_1(struct ub_lun *lun, struct request *rq)
 807 {
 808         struct ub_dev *sc = lun->udev;
 809         struct ub_scsi_cmd *cmd;
 810         struct ub_request *urq;
 811         int n_elem;
 812
 813         if (atomic_read(&sc->poison) || lun->changed) {
 814                 blkdev_dequeue_request(rq);
 815                 ub_end_rq(rq, 0);
 816                 return 0;
 817         }
 818
 819         if (lun->urq.rq != NULL)
 820                 return -1;
 821         if ((cmd = ub_get_cmd(lun)) == NULL)
 822                 return -1;
 823         memset(cmd, 0, sizeof(struct ub_scsi_cmd));
 824
 825         blkdev_dequeue_request(rq);
 826
 827         urq = &lun->urq;
 828         memset(urq, 0, sizeof(struct ub_request));
 829         urq->rq = rq;
 830
 831         /*
 832          * get scatterlist from block layer
 833          */
 834         n_elem = blk_rq_map_sg(lun->disk->queue, rq, &urq->sgv[0]);
 835         if (n_elem < 0) {
 836                 printk(KERN_INFO "%s: failed request map (%d)\n",
 837                     lun->name, n_elem); /* P3 */
 838                 goto drop;
 839         }
 840         if (n_elem > UB_MAX_REQ_SG) {   /* Paranoia */
 841                 printk(KERN_WARNING "%s: request with %d segments\n",
 842                     lun->name, n_elem);
 843                 goto drop;
 844         }
 845         urq->nsg = n_elem;
 846         sc->sg_stat[n_elem < 5 ? n_elem : 5]++;
 847
 848         if (blk_pc_request(rq)) {
 849                 ub_cmd_build_packet(sc, lun, cmd, urq);
 850         } else {
 851                 ub_cmd_build_block(sc, lun, cmd, urq);
 852         }
 853         cmd->state = UB_CMDST_INIT;
 854         cmd->lun = lun;
 855         cmd->done = ub_rw_cmd_done;
 856         cmd->back = urq;
 857
 858         cmd->tag = sc->tagcnt++;
 859         if (ub_submit_scsi(sc, cmd) != 0)
 860                 goto drop;
 861
 862         return 0;
 863
 864 drop:
 865         ub_put_cmd(lun, cmd);
 866         ub_end_rq(rq, 0);
 867         return 0;
 868 }
 869
 870 static void ub_cmd_build_block(struct ub_dev *sc, struct ub_lun *lun,
 871     struct ub_scsi_cmd *cmd, struct ub_request *urq)
 872 {
 873         struct request *rq = urq->rq;
 874         unsigned int block, nblks;
 875
 876         if (rq_data_dir(rq) == WRITE)
 877                 cmd->dir = UB_DIR_WRITE;
 878         else
 879                 cmd->dir = UB_DIR_READ;
 880
 881         cmd->nsg = urq->nsg;
 882         memcpy(cmd->sgv, urq->sgv, sizeof(struct scatterlist) * cmd->nsg);
 883
 884         /*
 885          * build the command
 886          *
 887          * The call to blk_queue_hardsect_size() guarantees that request
 888          * is aligned, but it is given in terms of 512 byte units, always.
 889          */
 890         block = rq->sector >> lun->capacity.bshift;
 891         nblks = rq->nr_sectors >> lun->capacity.bshift;
 892
 893         cmd->cdb[0] = (cmd->dir == UB_DIR_READ)? READ_10: WRITE_10;
 894         /* 10-byte uses 4 bytes of LBA: 2147483648KB, 2097152MB, 2048GB */
 895         cmd->cdb[2] = block >> 24;
 896         cmd->cdb[3] = block >> 16;
 897         cmd->cdb[4] = block >> 8;
 898         cmd->cdb[5] = block;
 899         cmd->cdb[7] = nblks >> 8;
 900         cmd->cdb[8] = nblks;
 901         cmd->cdb_len = 10;
 902
 903         cmd->len = rq->nr_sectors * 512;
 904 }
 905
 906 static void ub_cmd_build_packet(struct ub_dev *sc, struct ub_lun *lun,
 907     struct ub_scsi_cmd *cmd, struct ub_request *urq)
 908 {
 909         struct request *rq = urq->rq;
 910
 911         if (rq->data_len == 0) {
 912                 cmd->dir = UB_DIR_NONE;
 913         } else {
 914                 if (rq_data_dir(rq) == WRITE)
 915                         cmd->dir = UB_DIR_WRITE;
 916                 else
 917                         cmd->dir = UB_DIR_READ;
 918         }
 919
 920         cmd->nsg = urq->nsg;
 921         memcpy(cmd->sgv, urq->sgv, sizeof(struct scatterlist) * cmd->nsg);
 922
 923         memcpy(&cmd->cdb, rq->cmd, rq->cmd_len);
 924         cmd->cdb_len = rq->cmd_len;
 925
 926         cmd->len = rq->data_len;
 927 }
 928
 929 static void ub_rw_cmd_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
 930 {
 931         struct ub_lun *lun = cmd->lun;
 932         struct ub_request *urq = cmd->back;
 933         struct request *rq;
 934         int uptodate;
 935
 936         rq = urq->rq;
 937
 938         if (cmd->error == 0) {
 939                 uptodate = 1;
 940
 941                 if (blk_pc_request(rq)) {
 942                         if (cmd->act_len >= rq->data_len)
 943                                 rq->data_len = 0;
 944                         else
 945                                 rq->data_len -= cmd->act_len;
 946                 }
 947         } else {
 948                 uptodate = 0;
 949
 950                 if (blk_pc_request(rq)) {
 951                         /* UB_SENSE_SIZE is smaller than SCSI_SENSE_BUFFERSIZE */
 952                         memcpy(rq->sense, sc->top_sense, UB_SENSE_SIZE);
 953                         rq->sense_len = UB_SENSE_SIZE;
 954                         if (sc->top_sense[0] != 0)
 955                                 rq->errors = SAM_STAT_CHECK_CONDITION;
 956                         else
 957                                 rq->errors = DID_ERROR << 16;
 958                 } else {
 959                         if (cmd->error == -EIO) {
 960                                 if (ub_rw_cmd_retry(sc, lun, urq, cmd) == 0)
 961                                         return;
 962                         }
 963                 }
 964         }
 965
 966         urq->rq = NULL;
 967
 968         ub_put_cmd(lun, cmd);
 969         ub_end_rq(rq, uptodate);
 970         blk_start_queue(lun->disk->queue);
 971 }
 972
 973 static void ub_end_rq(struct request *rq, int uptodate)
 974 {
 975         end_that_request_first(rq, uptodate, rq->hard_nr_sectors);
 976         end_that_request_last(rq, uptodate);
 977 }
 978
 979 static int ub_rw_cmd_retry(struct ub_dev *sc, struct ub_lun *lun,
 980     struct ub_request *urq, struct ub_scsi_cmd *cmd)
 981 {
 982
 983         if (atomic_read(&sc->poison))
 984                 return -ENXIO;
 985
 986         ub_reset_enter(sc);
 987
 988         if (urq->current_try >= 3)
 989                 return -EIO;
 990         urq->current_try++;
 991         /* P3 */ printk("%s: dir %c len/act %d/%d "
 992             "[sense %x %02x %02x] retry %d\n",
 993             sc->name, UB_DIR_CHAR(cmd->dir), cmd->len, cmd->act_len,
 994             cmd->key, cmd->asc, cmd->ascq, urq->current_try);
 995
 996         memset(cmd, 0, sizeof(struct ub_scsi_cmd));
 997         ub_cmd_build_block(sc, lun, cmd, urq);
 998
 999         cmd->state = UB_CMDST_INIT;
1000         cmd->lun = lun;
1001         cmd->done = ub_rw_cmd_done;
1002         cmd->back = urq;
1003
1004         cmd->tag = sc->tagcnt++;
1005
1006 #if 0 /* Wasteful */
1007         return ub_submit_scsi(sc, cmd);
1008 #else
1009         ub_cmdq_add(sc, cmd);
1010         return 0;
1011 #endif
1012 }
1013
1014 /*
1015  * Submit a regular SCSI operation (not an auto-sense).
1016  *
1017  * The Iron Law of Good Submit Routine is:
1018  * Zero return - callback is done, Nonzero return - callback is not done.
1019  * No exceptions.
1020  *
1021  * Host is assumed locked.
1022  *
1023  * XXX We only support Bulk for the moment.
1024  */
1025 static int ub_submit_scsi(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1026 {
1027
1028         if (cmd->state != UB_CMDST_INIT ||
1029             (cmd->dir != UB_DIR_NONE && cmd->len == 0)) {
1030                 return -EINVAL;
1031         }
1032
1033         ub_cmdq_add(sc, cmd);
1034         /*
1035          * We can call ub_scsi_dispatch(sc) right away here, but it's a little
1036          * safer to jump to a tasklet, in case upper layers do something silly.
1037          */
1038         tasklet_schedule(&sc->tasklet);
1039         return 0;
1040 }
1041
1042 /*
1043  * Submit the first URB for the queued command.
1044  * This function does not deal with queueing in any way.
1045  */
1046 static int ub_scsi_cmd_start(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1047 {
1048         struct bulk_cb_wrap *bcb;
1049         int rc;
1050
1051         bcb = &sc->work_bcb;
1052
1053         /*
1054          * ``If the allocation length is eighteen or greater, and a device
1055          * server returns less than eithteen bytes of data, the application
1056          * client should assume that the bytes not transferred would have been
1057          * zeroes had the device server returned those bytes.''
1058          *
1059          * We zero sense for all commands so that when a packet request
1060          * fails it does not return a stale sense.
1061          */
1062         memset(&sc->top_sense, 0, UB_SENSE_SIZE);
1063
1064         /* set up the command wrapper */
1065         bcb->Signature = cpu_to_le32(US_BULK_CB_SIGN);
1066         bcb->Tag = cmd->tag;            /* Endianness is not important */
1067         bcb->DataTransferLength = cpu_to_le32(cmd->len);
1068         bcb->Flags = (cmd->dir == UB_DIR_READ) ? 0x80 : 0;
1069         bcb->Lun = (cmd->lun != NULL) ? cmd->lun->num : 0;
1070         bcb->Length = cmd->cdb_len;
1071
1072         /* copy the command payload */
1073         memcpy(bcb->CDB, cmd->cdb, UB_MAX_CDB_SIZE);
1074
1075         UB_INIT_COMPLETION(sc->work_done);
1076
1077         sc->last_pipe = sc->send_bulk_pipe;
1078         usb_fill_bulk_urb(&sc->work_urb, sc->dev, sc->send_bulk_pipe,
1079             bcb, US_BULK_CB_WRAP_LEN, ub_urb_complete, sc);
1080
1081         /* Fill what we shouldn't be filling, because usb-storage did so. */
1082         sc->work_urb.actual_length = 0;
1083         sc->work_urb.error_count = 0;
1084         sc->work_urb.status = 0;
1085
1086         if ((rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC)) != 0) {
1087                 /* XXX Clear stalls */
1088                 ub_complete(&sc->work_done);
1089                 return rc;
1090         }
1091
1092         sc->work_timer.expires = jiffies + UB_URB_TIMEOUT;
1093         add_timer(&sc->work_timer);
1094
1095         cmd->state = UB_CMDST_CMD;
1096         ub_cmdtr_state(sc, cmd);
1097         return 0;
1098 }
1099
1100 /*
1101  * Timeout handler.
1102  */
1103 static void ub_urb_timeout(unsigned long arg)
1104 {
1105         struct ub_dev *sc = (struct ub_dev *) arg;
1106         unsigned long flags;
1107
1108         spin_lock_irqsave(sc->lock, flags);
1109         if (!ub_is_completed(&sc->work_done))
1110                 usb_unlink_urb(&sc->work_urb);
1111         spin_unlock_irqrestore(sc->lock, flags);
1112 }
1113
1114 /*
1115  * Completion routine for the work URB.
1116  *
1117  * This can be called directly from usb_submit_urb (while we have
1118  * the sc->lock taken) and from an interrupt (while we do NOT have
1119  * the sc->lock taken). Therefore, bounce this off to a tasklet.
1120  */
1121 static void ub_urb_complete(struct urb *urb, struct pt_regs *pt)
1122 {
1123         struct ub_dev *sc = urb->context;
1124
1125         ub_complete(&sc->work_done);
1126         tasklet_schedule(&sc->tasklet);
1127 }
1128
1129 static void ub_scsi_action(unsigned long _dev)
1130 {
1131         struct ub_dev *sc = (struct ub_dev *) _dev;
1132         unsigned long flags;
1133
1134         spin_lock_irqsave(sc->lock, flags);
1135         ub_scsi_dispatch(sc);
1136         spin_unlock_irqrestore(sc->lock, flags);
1137 }
1138
1139 static void ub_scsi_dispatch(struct ub_dev *sc)
1140 {
1141         struct ub_scsi_cmd *cmd;
1142         int rc;
1143
1144         while (!sc->reset && (cmd = ub_cmdq_peek(sc)) != NULL) {
1145                 if (cmd->state == UB_CMDST_DONE) {
1146                         ub_cmdq_pop(sc);
1147                         (*cmd->done)(sc, cmd);
1148                 } else if (cmd->state == UB_CMDST_INIT) {
1149                         ub_cmdtr_new(sc, cmd);
1150                         if ((rc = ub_scsi_cmd_start(sc, cmd)) == 0)
1151                                 break;
1152                         cmd->error = rc;
1153                         cmd->state = UB_CMDST_DONE;
1154                         ub_cmdtr_state(sc, cmd);
1155                 } else {
1156                         if (!ub_is_completed(&sc->work_done))
1157                                 break;
1158                         del_timer(&sc->work_timer);
1159                         ub_scsi_urb_compl(sc, cmd);
1160                 }
1161         }
1162 }
1163
1164 static void ub_scsi_urb_compl(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1165 {
1166         struct urb *urb = &sc->work_urb;
1167         struct bulk_cs_wrap *bcs;
1168         int len;
1169         int rc;
1170
1171         if (atomic_read(&sc->poison)) {
1172                 ub_state_done(sc, cmd, -ENODEV);
1173                 return;
1174         }
1175
1176         if (cmd->state == UB_CMDST_CLEAR) {
1177                 if (urb->status == -EPIPE) {
1178                         /*
1179                          * STALL while clearning STALL.
1180                          * The control pipe clears itself - nothing to do.
1181                          */
1182                         printk(KERN_NOTICE "%s: stall on control pipe\n",
1183                             sc->name);
1184                         goto Bad_End;
1185                 }
1186
1187                 /*
1188                  * We ignore the result for the halt clear.
1189                  */
1190
1191                 /* reset the endpoint toggle */
1192                 usb_settoggle(sc->dev, usb_pipeendpoint(sc->last_pipe),
1193                         usb_pipeout(sc->last_pipe), 0);
1194
1195                 ub_state_sense(sc, cmd);
1196
1197         } else if (cmd->state == UB_CMDST_CLR2STS) {
1198                 if (urb->status == -EPIPE) {
1199                         printk(KERN_NOTICE "%s: stall on control pipe\n",
1200                             sc->name);
1201                         goto Bad_End;
1202                 }
1203
1204                 /*
1205                  * We ignore the result for the halt clear.
1206                  */
1207
1208                 /* reset the endpoint toggle */
1209                 usb_settoggle(sc->dev, usb_pipeendpoint(sc->last_pipe),
1210                         usb_pipeout(sc->last_pipe), 0);
1211
1212                 ub_state_stat(sc, cmd);
1213
1214         } else if (cmd->state == UB_CMDST_CLRRS) {
1215                 if (urb->status == -EPIPE) {
1216                         printk(KERN_NOTICE "%s: stall on control pipe\n",
1217                             sc->name);
1218                         goto Bad_End;
1219                 }
1220
1221                 /*
1222                  * We ignore the result for the halt clear.
1223                  */
1224
1225                 /* reset the endpoint toggle */
1226                 usb_settoggle(sc->dev, usb_pipeendpoint(sc->last_pipe),
1227                         usb_pipeout(sc->last_pipe), 0);
1228
1229                 ub_state_stat_counted(sc, cmd);
1230
1231         } else if (cmd->state == UB_CMDST_CMD) {
1232                 switch (urb->status) {
1233                 case 0:
1234                         break;
1235                 case -EOVERFLOW:
1236                         goto Bad_End;
1237                 case -EPIPE:
1238                         rc = ub_submit_clear_stall(sc, cmd, sc->last_pipe);
1239                         if (rc != 0) {
1240                                 printk(KERN_NOTICE "%s: "
1241                                     "unable to submit clear (%d)\n",
1242                                     sc->name, rc);
1243                                 /*
1244                                  * This is typically ENOMEM or some other such shit.
1245                                  * Retrying is pointless. Just do Bad End on it...
1246                                  */
1247                                 ub_state_done(sc, cmd, rc);
1248                                 return;
1249                         }
1250                         cmd->state = UB_CMDST_CLEAR;
1251                         ub_cmdtr_state(sc, cmd);
1252                         return;
1253                 case -ESHUTDOWN:        /* unplug */
1254                 case -EILSEQ:           /* unplug timeout on uhci */
1255                         ub_state_done(sc, cmd, -ENODEV);
1256                         return;
1257                 default:
1258                         goto Bad_End;
1259                 }
1260                 if (urb->actual_length != US_BULK_CB_WRAP_LEN) {
1261                         goto Bad_End;
1262                 }
1263
1264                 if (cmd->dir == UB_DIR_NONE || cmd->nsg < 1) {
1265                         ub_state_stat(sc, cmd);
1266                         return;
1267                 }
1268
1269                 // udelay(125);         // usb-storage has this
1270                 ub_data_start(sc, cmd);
1271
1272         } else if (cmd->state == UB_CMDST_DATA) {
1273                 if (urb->status == -EPIPE) {
1274                         rc = ub_submit_clear_stall(sc, cmd, sc->last_pipe);
1275                         if (rc != 0) {
1276                                 printk(KERN_NOTICE "%s: "
1277                                     "unable to submit clear (%d)\n",
1278                                     sc->name, rc);
1279                                 ub_state_done(sc, cmd, rc);
1280                                 return;
1281                         }
1282                         cmd->state = UB_CMDST_CLR2STS;
1283                         ub_cmdtr_state(sc, cmd);
1284                         return;
1285                 }
1286                 if (urb->status == -EOVERFLOW) {
1287                         /*
1288                          * A babble? Failure, but we must transfer CSW now.
1289                          */
1290                         cmd->error = -EOVERFLOW;        /* A cheap trick... */
1291                         ub_state_stat(sc, cmd);
1292                         return;
1293                 }
1294
1295                 if (cmd->dir == UB_DIR_WRITE) {
1296                         /*
1297                          * Do not continue writes in case of a failure.
1298                          * Doing so would cause sectors to be mixed up,
1299                          * which is worse than sectors lost.
1300                          *
1301                          * We must try to read the CSW, or many devices
1302                          * get confused.
1303                          */
1304                         len = urb->actual_length;
1305                         if (urb->status != 0 ||
1306                             len != cmd->sgv[cmd->current_sg].length) {
1307                                 cmd->act_len += len;
1308                                 ub_cmdtr_act_len(sc, cmd);
1309
1310                                 cmd->error = -EIO;
1311                                 ub_state_stat(sc, cmd);
1312                                 return;
1313                         }
1314
1315                 } else {
1316                         /*
1317                          * If an error occurs on read, we record it, and
1318                          * continue to fetch data in order to avoid bubble.
1319                          *
1320                          * As a small shortcut, we stop if we detect that
1321                          * a CSW mixed into data.
1322                          */
1323                         if (urb->status != 0)
1324                                 cmd->error = -EIO;
1325
1326                         len = urb->actual_length;
1327                         if (urb->status != 0 ||
1328                             len != cmd->sgv[cmd->current_sg].length) {
1329                                 if ((len & 0x1FF) == US_BULK_CS_WRAP_LEN)
1330                                         goto Bad_End;
1331                         }
1332                 }
1333
1334                 cmd->act_len += urb->actual_length;
1335                 ub_cmdtr_act_len(sc, cmd);
1336
1337                 if (++cmd->current_sg < cmd->nsg) {
1338                         ub_data_start(sc, cmd);
1339                         return;
1340                 }
1341                 ub_state_stat(sc, cmd);
1342
1343         } else if (cmd->state == UB_CMDST_STAT) {
1344                 if (urb->status == -EPIPE) {
1345                         rc = ub_submit_clear_stall(sc, cmd, sc->last_pipe);
1346                         if (rc != 0) {
1347                                 printk(KERN_NOTICE "%s: "
1348                                     "unable to submit clear (%d)\n",
1349                                     sc->name, rc);
1350                                 ub_state_done(sc, cmd, rc);
1351                                 return;
1352                         }
1353
1354                         /*
1355                          * Having a stall when getting CSW is an error, so
1356                          * make sure uppper levels are not oblivious to it.
1357                          */
1358                         cmd->error = -EIO;              /* A cheap trick... */
1359
1360                         cmd->state = UB_CMDST_CLRRS;
1361                         ub_cmdtr_state(sc, cmd);
1362                         return;
1363                 }
1364
1365                 /* Catch everything, including -EOVERFLOW and other nasties. */
1366                 if (urb->status != 0)
1367                         goto Bad_End;
1368
1369                 if (urb->actual_length == 0) {
1370                         ub_state_stat_counted(sc, cmd);
1371                         return;
1372                 }
1373
1374                 /*
1375                  * Check the returned Bulk protocol status.
1376                  * The status block has to be validated first.
1377                  */
1378
1379                 bcs = &sc->work_bcs;
1380
1381                 if (sc->signature == cpu_to_le32(0)) {
1382                         /*
1383                          * This is the first reply, so do not perform the check.
1384                          * Instead, remember the signature the device uses
1385                          * for future checks. But do not allow a nul.
1386                          */
1387                         sc->signature = bcs->Signature;
1388                         if (sc->signature == cpu_to_le32(0)) {
1389                                 ub_state_stat_counted(sc, cmd);
1390                                 return;
1391                         }
1392                 } else {
1393                         if (bcs->Signature != sc->signature) {
1394                                 ub_state_stat_counted(sc, cmd);
1395                                 return;
1396                         }
1397                 }
1398
1399                 if (bcs->Tag != cmd->tag) {
1400                         /*
1401                          * This usually happens when we disagree with the
1402                          * device's microcode about something. For instance,
1403                          * a few of them throw this after timeouts. They buffer
1404                          * commands and reply at commands we timed out before.
1405                          * Without flushing these replies we loop forever.
1406                          */
1407                         ub_state_stat_counted(sc, cmd);
1408                         return;
1409                 }
1410
1411                 len = le32_to_cpu(bcs->Residue);
1412                 if (len != cmd->len - cmd->act_len) {
1413                         /*
1414                          * It is all right to transfer less, the caller has
1415                          * to check. But it's not all right if the device
1416                          * counts disagree with our counts.
1417                          */
1418                         /* P3 */ printk("%s: resid %d len %d act %d\n",
1419                             sc->name, len, cmd->len, cmd->act_len);
1420                         goto Bad_End;
1421                 }
1422
1423                 switch (bcs->Status) {
1424                 case US_BULK_STAT_OK:
1425                         break;
1426                 case US_BULK_STAT_FAIL:
1427                         ub_state_sense(sc, cmd);
1428                         return;
1429                 case US_BULK_STAT_PHASE:
1430                         /* P3 */ printk("%s: status PHASE\n", sc->name);
1431                         goto Bad_End;
1432                 default:
1433                         printk(KERN_INFO "%s: unknown CSW status 0x%x\n",
1434                             sc->name, bcs->Status);
1435                         ub_state_done(sc, cmd, -EINVAL);
1436                         return;
1437                 }
1438
1439                 /* Not zeroing error to preserve a babble indicator */
1440                 if (cmd->error != 0) {
1441                         ub_state_sense(sc, cmd);
1442                         return;
1443                 }
1444                 cmd->state = UB_CMDST_DONE;
1445                 ub_cmdtr_state(sc, cmd);
1446                 ub_cmdq_pop(sc);
1447                 (*cmd->done)(sc, cmd);
1448
1449         } else if (cmd->state == UB_CMDST_SENSE) {
1450                 ub_state_done(sc, cmd, -EIO);
1451
1452         } else {
1453                 printk(KERN_WARNING "%s: "
1454                     "wrong command state %d\n",
1455                     sc->name, cmd->state);
1456                 ub_state_done(sc, cmd, -EINVAL);
1457                 return;
1458         }
1459         return;
1460
1461 Bad_End: /* Little Excel is dead */
1462         ub_state_done(sc, cmd, -EIO);
1463 }
1464
1465 /*
1466  * Factorization helper for the command state machine:
1467  * Initiate a data segment transfer.
1468  */
1469 static void ub_data_start(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1470 {
1471         struct scatterlist *sg = &cmd->sgv[cmd->current_sg];
1472         int pipe;
1473         int rc;
1474
1475         UB_INIT_COMPLETION(sc->work_done);
1476
1477         if (cmd->dir == UB_DIR_READ)
1478                 pipe = sc->recv_bulk_pipe;
1479         else
1480                 pipe = sc->send_bulk_pipe;
1481         sc->last_pipe = pipe;
1482         usb_fill_bulk_urb(&sc->work_urb, sc->dev, pipe,
1483             page_address(sg->page) + sg->offset, sg->length,
1484             ub_urb_complete, sc);
1485         sc->work_urb.actual_length = 0;
1486         sc->work_urb.error_count = 0;
1487         sc->work_urb.status = 0;
1488
1489         if ((rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC)) != 0) {
1490                 /* XXX Clear stalls */
1491                 ub_complete(&sc->work_done);
1492                 ub_state_done(sc, cmd, rc);
1493                 return;
1494         }
1495
1496         sc->work_timer.expires = jiffies + UB_DATA_TIMEOUT;
1497         add_timer(&sc->work_timer);
1498
1499         cmd->state = UB_CMDST_DATA;
1500         ub_cmdtr_state(sc, cmd);
1501 }
1502
1503 /*
1504  * Factorization helper for the command state machine:
1505  * Finish the command.
1506  */
1507 static void ub_state_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd, int rc)
1508 {
1509
1510         cmd->error = rc;
1511         cmd->state = UB_CMDST_DONE;
1512         ub_cmdtr_state(sc, cmd);
1513         ub_cmdq_pop(sc);
1514         (*cmd->done)(sc, cmd);
1515 }
1516
1517 /*
1518  * Factorization helper for the command state machine:
1519  * Submit a CSW read.
1520  */
1521 static int __ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1522 {
1523         int rc;
1524
1525         UB_INIT_COMPLETION(sc->work_done);
1526
1527         sc->last_pipe = sc->recv_bulk_pipe;
1528         usb_fill_bulk_urb(&sc->work_urb, sc->dev, sc->recv_bulk_pipe,
1529             &sc->work_bcs, US_BULK_CS_WRAP_LEN, ub_urb_complete, sc);
1530         sc->work_urb.actual_length = 0;
1531         sc->work_urb.error_count = 0;
1532         sc->work_urb.status = 0;
1533
1534         if ((rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC)) != 0) {
1535                 /* XXX Clear stalls */
1536                 ub_complete(&sc->work_done);
1537                 ub_state_done(sc, cmd, rc);
1538                 return -1;
1539         }
1540
1541         sc->work_timer.expires = jiffies + UB_STAT_TIMEOUT;
1542         add_timer(&sc->work_timer);
1543         return 0;
1544 }
1545
1546 /*
1547  * Factorization helper for the command state machine:
1548  * Submit a CSW read and go to STAT state.
1549  */
1550 static void ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1551 {
1552
1553         if (__ub_state_stat(sc, cmd) != 0)
1554                 return;
1555
1556         cmd->stat_count = 0;
1557         cmd->state = UB_CMDST_STAT;
1558         ub_cmdtr_state(sc, cmd);
1559 }
1560
1561 /*
1562  * Factorization helper for the command state machine:
1563  * Submit a CSW read and go to STAT state with counter (along [C] path).
1564  */
1565 static void ub_state_stat_counted(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1566 {
1567
1568         if (++cmd->stat_count >= 4) {
1569                 ub_state_sense(sc, cmd);
1570                 return;
1571         }
1572
1573         if (__ub_state_stat(sc, cmd) != 0)
1574                 return;
1575
1576         cmd->state = UB_CMDST_STAT;
1577         ub_cmdtr_state(sc, cmd);
1578 }
1579
1580 /*
1581  * Factorization helper for the command state machine:
1582  * Submit a REQUEST SENSE and go to SENSE state.
1583  */
1584 static void ub_state_sense(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1585 {
1586         struct ub_scsi_cmd *scmd;
1587         struct scatterlist *sg;
1588         int rc;
1589
1590         if (cmd->cdb[0] == REQUEST_SENSE) {
1591                 rc = -EPIPE;
1592                 goto error;
1593         }
1594
1595         scmd = &sc->top_rqs_cmd;
1596         memset(scmd, 0, sizeof(struct ub_scsi_cmd));
1597         scmd->cdb[0] = REQUEST_SENSE;
1598         scmd->cdb[4] = UB_SENSE_SIZE;
1599         scmd->cdb_len = 6;
1600         scmd->dir = UB_DIR_READ;
1601         scmd->state = UB_CMDST_INIT;
1602         scmd->nsg = 1;
1603         sg = &scmd->sgv[0];
1604         sg->page = virt_to_page(sc->top_sense);
1605         sg->offset = (unsigned long)sc->top_sense & (PAGE_SIZE-1);
1606         sg->length = UB_SENSE_SIZE;
1607         scmd->len = UB_SENSE_SIZE;
1608         scmd->lun = cmd->lun;
1609         scmd->done = ub_top_sense_done;
1610         scmd->back = cmd;
1611
1612         scmd->tag = sc->tagcnt++;
1613
1614         cmd->state = UB_CMDST_SENSE;
1615         ub_cmdtr_state(sc, cmd);
1616
1617         ub_cmdq_insert(sc, scmd);
1618         return;
1619
1620 error:
1621         ub_state_done(sc, cmd, rc);
1622 }
1623
1624 /*
1625  * A helper for the command's state machine:
1626  * Submit a stall clear.
1627  */
1628 static int ub_submit_clear_stall(struct ub_dev *sc, struct ub_scsi_cmd *cmd,
1629     int stalled_pipe)
1630 {
1631         int endp;
1632         struct usb_ctrlrequest *cr;
1633         int rc;
1634
1635         endp = usb_pipeendpoint(stalled_pipe);
1636         if (usb_pipein (stalled_pipe))
1637                 endp |= USB_DIR_IN;
1638
1639         cr = &sc->work_cr;
1640         cr->bRequestType = USB_RECIP_ENDPOINT;
1641         cr->bRequest = USB_REQ_CLEAR_FEATURE;
1642         cr->wValue = cpu_to_le16(USB_ENDPOINT_HALT);
1643         cr->wIndex = cpu_to_le16(endp);
1644         cr->wLength = cpu_to_le16(0);
1645
1646         UB_INIT_COMPLETION(sc->work_done);
1647
1648         usb_fill_control_urb(&sc->work_urb, sc->dev, sc->send_ctrl_pipe,
1649             (unsigned char*) cr, NULL, 0, ub_urb_complete, sc);
1650         sc->work_urb.actual_length = 0;
1651         sc->work_urb.error_count = 0;
1652         sc->work_urb.status = 0;
1653
1654         if ((rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC)) != 0) {
1655                 ub_complete(&sc->work_done);
1656                 return rc;
1657         }
1658
1659         sc->work_timer.expires = jiffies + UB_CTRL_TIMEOUT;
1660         add_timer(&sc->work_timer);
1661         return 0;
1662 }
1663
1664 /*
1665  */
1666 static void ub_top_sense_done(struct ub_dev *sc, struct ub_scsi_cmd *scmd)
1667 {
1668         unsigned char *sense = sc->top_sense;
1669         struct ub_scsi_cmd *cmd;
1670
1671         /*
1672          * Ignoring scmd->act_len, because the buffer was pre-zeroed.
1673          */
1674         ub_cmdtr_sense(sc, scmd, sense);
1675
1676         /*
1677          * Find the command which triggered the unit attention or a check,
1678          * save the sense into it, and advance its state machine.
1679          */
1680         if ((cmd = ub_cmdq_peek(sc)) == NULL) {
1681                 printk(KERN_WARNING "%s: sense done while idle\n", sc->name);
1682                 return;
1683         }
1684         if (cmd != scmd->back) {
1685                 printk(KERN_WARNING "%s: "
1686                     "sense done for wrong command 0x%x\n",
1687                     sc->name, cmd->tag);
1688                 return;
1689         }
1690         if (cmd->state != UB_CMDST_SENSE) {
1691                 printk(KERN_WARNING "%s: "
1692                     "sense done with bad cmd state %d\n",
1693                     sc->name, cmd->state);
1694                 return;
1695         }
1696
1697         cmd->key = sense[2] & 0x0F;
1698         cmd->asc = sense[12];
1699         cmd->ascq = sense[13];
1700
1701         ub_scsi_urb_compl(sc, cmd);
1702 }
1703
1704 /*
1705  * Reset management
1706  */
1707
1708 static void ub_reset_enter(struct ub_dev *sc)
1709 {
1710
1711         if (sc->reset) {
1712                 /* This happens often on multi-LUN devices. */
1713                 return;
1714         }
1715         sc->reset = 1;
1716
1717 #if 0 /* Not needed because the disconnect waits for us. */
1718         unsigned long flags;
1719         spin_lock_irqsave(&ub_lock, flags);
1720         sc->openc++;
1721         spin_unlock_irqrestore(&ub_lock, flags);
1722 #endif
1723
1724 #if 0 /* We let them stop themselves. */
1725         struct list_head *p;
1726         struct ub_lun *lun;
1727         list_for_each(p, &sc->luns) {
1728                 lun = list_entry(p, struct ub_lun, link);
1729                 blk_stop_queue(lun->disk->queue);
1730         }
1731 #endif
1732
1733         schedule_work(&sc->reset_work);
1734 }
1735
1736 static void ub_reset_task(void *arg)
1737 {
1738         struct ub_dev *sc = arg;
1739         unsigned long flags;
1740         struct list_head *p;
1741         struct ub_lun *lun;
1742         int lkr, rc;
1743
1744         if (!sc->reset) {
1745                 printk(KERN_WARNING "%s: Running reset unrequested\n",
1746                     sc->name);
1747                 return;
1748         }
1749
1750         if (atomic_read(&sc->poison)) {
1751                 printk(KERN_NOTICE "%s: Not resetting disconnected device\n",
1752                     sc->name); /* P3 This floods. Remove soon. XXX */
1753         } else if (sc->dev->actconfig->desc.bNumInterfaces != 1) {
1754                 printk(KERN_NOTICE "%s: Not resetting multi-interface device\n",
1755                     sc->name); /* P3 This floods. Remove soon. XXX */
1756         } else {
1757                 if ((lkr = usb_lock_device_for_reset(sc->dev, sc->intf)) < 0) {
1758                         printk(KERN_NOTICE
1759                             "%s: usb_lock_device_for_reset failed (%d)\n",
1760                             sc->name, lkr);
1761                 } else {
1762                         rc = usb_reset_device(sc->dev);
1763                         if (rc < 0) {
1764                                 printk(KERN_NOTICE "%s: "
1765                                     "usb_lock_device_for_reset failed (%d)\n",
1766                                     sc->name, rc);
1767                         }
1768
1769                         if (lkr)
1770                                 usb_unlock_device(sc->dev);
1771                 }
1772         }
1773
1774         /*
1775          * In theory, no commands can be running while reset is active,
1776          * so nobody can ask for another reset, and so we do not need any
1777          * queues of resets or anything. We do need a spinlock though,
1778          * to interact with block layer.
1779          */
1780         spin_lock_irqsave(sc->lock, flags);
1781         sc->reset = 0;
1782         tasklet_schedule(&sc->tasklet);
1783         list_for_each(p, &sc->luns) {
1784                 lun = list_entry(p, struct ub_lun, link);
1785                 blk_start_queue(lun->disk->queue);
1786         }
1787         wake_up(&sc->reset_wait);
1788         spin_unlock_irqrestore(sc->lock, flags);
1789 }
1790
1791 /*
1792  * This is called from a process context.
1793  */
1794 static void ub_revalidate(struct ub_dev *sc, struct ub_lun *lun)
1795 {
1796
1797         lun->readonly = 0;      /* XXX Query this from the device */
1798
1799         lun->capacity.nsec = 0;
1800         lun->capacity.bsize = 512;
1801         lun->capacity.bshift = 0;
1802
1803         if (ub_sync_tur(sc, lun) != 0)
1804                 return;                 /* Not ready */
1805         lun->changed = 0;
1806
1807         if (ub_sync_read_cap(sc, lun, &lun->capacity) != 0) {
1808                 /*
1809                  * The retry here means something is wrong, either with the
1810                  * device, with the transport, or with our code.
1811                  * We keep this because sd.c has retries for capacity.
1812                  */
1813                 if (ub_sync_read_cap(sc, lun, &lun->capacity) != 0) {
1814                         lun->capacity.nsec = 0;
1815                         lun->capacity.bsize = 512;
1816                         lun->capacity.bshift = 0;
1817                 }
1818         }
1819 }
1820
1821 /*
1822  * The open funcion.
1823  * This is mostly needed to keep refcounting, but also to support
1824  * media checks on removable media drives.
1825  */
1826 static int ub_bd_open(struct inode *inode, struct file *filp)
1827 {
1828         struct gendisk *disk = inode->i_bdev->bd_disk;
1829         struct ub_lun *lun;
1830         struct ub_dev *sc;
1831         unsigned long flags;
1832         int rc;
1833
1834         if ((lun = disk->private_data) == NULL)
1835                 return -ENXIO;
1836         sc = lun->udev;
1837
1838         spin_lock_irqsave(&ub_lock, flags);
1839         if (atomic_read(&sc->poison)) {
1840                 spin_unlock_irqrestore(&ub_lock, flags);
1841                 return -ENXIO;
1842         }
1843         sc->openc++;
1844         spin_unlock_irqrestore(&ub_lock, flags);
1845
1846         /*
1847          * This is a workaround for a specific problem in our block layer.
1848          * In 2.6.9, register_disk duplicates the code from rescan_partitions.
1849          * However, if we do add_disk with a device which persistently reports
1850          * a changed media, add_disk calls register_disk, which does do_open,
1851          * which will call rescan_paritions for changed media. After that,
1852          * register_disk attempts to do it all again and causes double kobject
1853          * registration and a eventually an oops on module removal.
1854          *
1855          * The bottom line is, Al Viro says that we should not allow
1856          * bdev->bd_invalidated to be set when doing add_disk no matter what.
1857          */
1858         if (lun->first_open) {
1859                 lun->first_open = 0;
1860                 if (lun->changed) {
1861                         rc = -ENOMEDIUM;
1862                         goto err_open;
1863                 }
1864         }
1865
1866         if (lun->removable || lun->readonly)
1867                 check_disk_change(inode->i_bdev);
1868
1869         /*
1870          * The sd.c considers ->media_present and ->changed not equivalent,
1871          * under some pretty murky conditions (a failure of READ CAPACITY).
1872          * We may need it one day.
1873          */
1874         if (lun->removable && lun->changed && !(filp->f_flags & O_NDELAY)) {
1875                 rc = -ENOMEDIUM;
1876                 goto err_open;
1877         }
1878
1879         if (lun->readonly && (filp->f_mode & FMODE_WRITE)) {
1880                 rc = -EROFS;
1881                 goto err_open;
1882         }
1883
1884         return 0;
1885
1886 err_open:
1887         ub_put(sc);
1888         return rc;
1889 }
1890
1891 /*
1892  */
1893 static int ub_bd_release(struct inode *inode, struct file *filp)
1894 {
1895         struct gendisk *disk = inode->i_bdev->bd_disk;
1896         struct ub_lun *lun = disk->private_data;
1897         struct ub_dev *sc = lun->udev;
1898
1899         ub_put(sc);
1900         return 0;
1901 }
1902
1903 /*
1904  * The ioctl interface.
1905  */
1906 static int ub_bd_ioctl(struct inode *inode, struct file *filp,
1907     unsigned int cmd, unsigned long arg)
1908 {
1909         struct gendisk *disk = inode->i_bdev->bd_disk;
1910         void __user *usermem = (void __user *) arg;
1911
1912         return scsi_cmd_ioctl(filp, disk, cmd, usermem);
1913 }
1914
1915 /*
1916  * This is called once a new disk was seen by the block layer or by ub_probe().
1917  * The main onjective here is to discover the features of the media such as
1918  * the capacity, read-only status, etc. USB storage generally does not
1919  * need to be spun up, but if we needed it, this would be the place.
1920  *
1921  * This call can sleep.
1922  *
1923  * The return code is not used.
1924  */
1925 static int ub_bd_revalidate(struct gendisk *disk)
1926 {
1927         struct ub_lun *lun = disk->private_data;
1928
1929         ub_revalidate(lun->udev, lun);
1930
1931         /* XXX Support sector size switching like in sr.c */
1932         blk_queue_hardsect_size(disk->queue, lun->capacity.bsize);
1933         set_capacity(disk, lun->capacity.nsec);
1934         // set_disk_ro(sdkp->disk, lun->readonly);
1935
1936         return 0;
1937 }
1938
1939 /*
1940  * The check is called by the block layer to verify if the media
1941  * is still available. It is supposed to be harmless, lightweight and
1942  * non-intrusive in case the media was not changed.
1943  *
1944  * This call can sleep.
1945  *
1946  * The return code is bool!
1947  */
1948 static int ub_bd_media_changed(struct gendisk *disk)
1949 {
1950         struct ub_lun *lun = disk->private_data;
1951
1952         if (!lun->removable)
1953                 return 0;
1954
1955         /*
1956          * We clean checks always after every command, so this is not
1957          * as dangerous as it looks. If the TEST_UNIT_READY fails here,
1958          * the device is actually not ready with operator or software
1959          * intervention required. One dangerous item might be a drive which
1960          * spins itself down, and come the time to write dirty pages, this
1961          * will fail, then block layer discards the data. Since we never
1962          * spin drives up, such devices simply cannot be used with ub anyway.
1963          */
1964         if (ub_sync_tur(lun->udev, lun) != 0) {
1965                 lun->changed = 1;
1966                 return 1;
1967         }
1968
1969         return lun->changed;
1970 }
1971
1972 static struct block_device_operations ub_bd_fops = {
1973         .owner          = THIS_MODULE,
1974         .open           = ub_bd_open,
1975         .release        = ub_bd_release,
1976         .ioctl          = ub_bd_ioctl,
1977         .media_changed  = ub_bd_media_changed,
1978         .revalidate_disk = ub_bd_revalidate,
1979 };
1980
1981 /*
1982  * Common ->done routine for commands executed synchronously.
1983  */
1984 static void ub_probe_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1985 {
1986         struct completion *cop = cmd->back;
1987         complete(cop);
1988 }
1989
1990 /*
1991  * Test if the device has a check condition on it, synchronously.
1992  */
1993 static int ub_sync_tur(struct ub_dev *sc, struct ub_lun *lun)
1994 {
1995         struct ub_scsi_cmd *cmd;
1996         enum { ALLOC_SIZE = sizeof(struct ub_scsi_cmd) };
1997         unsigned long flags;
1998         struct completion compl;
1999         int rc;
2000
2001         init_completion(&compl);
2002
2003         rc = -ENOMEM;
2004         if ((cmd = kmalloc(ALLOC_SIZE, GFP_KERNEL)) == NULL)
2005                 goto err_alloc;
2006         memset(cmd, 0, ALLOC_SIZE);
2007
2008         cmd->cdb[0] = TEST_UNIT_READY;
2009         cmd->cdb_len = 6;
2010         cmd->dir = UB_DIR_NONE;
2011         cmd->state = UB_CMDST_INIT;
2012         cmd->lun = lun;                 /* This may be NULL, but that's ok */
2013         cmd->done = ub_probe_done;
2014         cmd->back = &compl;
2015
2016         spin_lock_irqsave(sc->lock, flags);
2017         cmd->tag = sc->tagcnt++;
2018
2019         rc = ub_submit_scsi(sc, cmd);
2020         spin_unlock_irqrestore(sc->lock, flags);
2021
2022         if (rc != 0) {
2023                 printk("ub: testing ready: submit error (%d)\n", rc); /* P3 */
2024                 goto err_submit;
2025         }
2026
2027         wait_for_completion(&compl);
2028
2029         rc = cmd->error;
2030
2031         if (rc == -EIO && cmd->key != 0)        /* Retries for benh's key */
2032                 rc = cmd->key;
2033
2034 err_submit:
2035         kfree(cmd);
2036 err_alloc:
2037         return rc;
2038 }
2039
2040 /*
2041  * Read the SCSI capacity synchronously (for probing).
2042  */
2043 static int ub_sync_read_cap(struct ub_dev *sc, struct ub_lun *lun,
2044     struct ub_capacity *ret)
2045 {
2046         struct ub_scsi_cmd *cmd;
2047         struct scatterlist *sg;
2048         char *p;
2049         enum { ALLOC_SIZE = sizeof(struct ub_scsi_cmd) + 8 };
2050         unsigned long flags;
2051         unsigned int bsize, shift;
2052         unsigned long nsec;
2053         struct completion compl;
2054         int rc;
2055
2056         init_completion(&compl);
2057
2058         rc = -ENOMEM;
2059         if ((cmd = kmalloc(ALLOC_SIZE, GFP_KERNEL)) == NULL)
2060                 goto err_alloc;
2061         memset(cmd, 0, ALLOC_SIZE);
2062         p = (char *)cmd + sizeof(struct ub_scsi_cmd);
2063
2064         cmd->cdb[0] = 0x25;
2065         cmd->cdb_len = 10;
2066         cmd->dir = UB_DIR_READ;
2067         cmd->state = UB_CMDST_INIT;
2068         cmd->nsg = 1;
2069         sg = &cmd->sgv[0];
2070         sg->page = virt_to_page(p);
2071         sg->offset = (unsigned long)p & (PAGE_SIZE-1);
2072         sg->length = 8;
2073         cmd->len = 8;
2074         cmd->lun = lun;
2075         cmd->done = ub_probe_done;
2076         cmd->back = &compl;
2077
2078         spin_lock_irqsave(sc->lock, flags);
2079         cmd->tag = sc->tagcnt++;
2080
2081         rc = ub_submit_scsi(sc, cmd);
2082         spin_unlock_irqrestore(sc->lock, flags);
2083
2084         if (rc != 0) {
2085                 printk("ub: reading capacity: submit error (%d)\n", rc); /* P3 */
2086                 goto err_submit;
2087         }
2088
2089         wait_for_completion(&compl);
2090
2091         if (cmd->error != 0) {
2092                 printk("ub: reading capacity: error %d\n", cmd->error); /* P3 */
2093                 rc = -EIO;
2094                 goto err_read;
2095         }
2096         if (cmd->act_len != 8) {
2097                 printk("ub: reading capacity: size %d\n", cmd->act_len); /* P3 */
2098                 rc = -EIO;
2099                 goto err_read;
2100         }
2101
2102         /* sd.c special-cases sector size of 0 to mean 512. Needed? Safe? */
2103         nsec = be32_to_cpu(*(__be32 *)p) + 1;
2104         bsize = be32_to_cpu(*(__be32 *)(p + 4));
2105         switch (bsize) {
2106         case 512:       shift = 0;      break;
2107         case 1024:      shift = 1;      break;
2108         case 2048:      shift = 2;      break;
2109         case 4096:      shift = 3;      break;
2110         default:
2111                 printk("ub: Bad sector size %u\n", bsize); /* P3 */
2112                 rc = -EDOM;
2113                 goto err_inv_bsize;
2114         }
2115
2116         ret->bsize = bsize;
2117         ret->bshift = shift;
2118         ret->nsec = nsec << shift;
2119         rc = 0;
2120
2121 err_inv_bsize:
2122 err_read:
2123 err_submit:
2124         kfree(cmd);
2125 err_alloc:
2126         return rc;
2127 }
2128
2129 /*
2130  */
2131 static void ub_probe_urb_complete(struct urb *urb, struct pt_regs *pt)
2132 {
2133         struct completion *cop = urb->context;
2134         complete(cop);
2135 }
2136
2137 static void ub_probe_timeout(unsigned long arg)
2138 {
2139         struct completion *cop = (struct completion *) arg;
2140         complete(cop);
2141 }
2142
2143 /*
2144  * Get number of LUNs by the way of Bulk GetMaxLUN command.
2145  */
2146 static int ub_sync_getmaxlun(struct ub_dev *sc)
2147 {
2148         int ifnum = sc->intf->cur_altsetting->desc.bInterfaceNumber;
2149         unsigned char *p;
2150         enum { ALLOC_SIZE = 1 };
2151         struct usb_ctrlrequest *cr;
2152         struct completion compl;
2153         struct timer_list timer;
2154         int nluns;
2155         int rc;
2156
2157         init_completion(&compl);
2158
2159         rc = -ENOMEM;
2160         if ((p = kmalloc(ALLOC_SIZE, GFP_KERNEL)) == NULL)
2161                 goto err_alloc;
2162         *p = 55;
2163
2164         cr = &sc->work_cr;
2165         cr->bRequestType = USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE;
2166         cr->bRequest = US_BULK_GET_MAX_LUN;
2167         cr->wValue = cpu_to_le16(0);
2168         cr->wIndex = cpu_to_le16(ifnum);
2169         cr->wLength = cpu_to_le16(1);
2170
2171         usb_fill_control_urb(&sc->work_urb, sc->dev, sc->recv_ctrl_pipe,
2172             (unsigned char*) cr, p, 1, ub_probe_urb_complete, &compl);
2173         sc->work_urb.actual_length = 0;
2174         sc->work_urb.error_count = 0;
2175         sc->work_urb.status = 0;
2176
2177         if ((rc = usb_submit_urb(&sc->work_urb, GFP_KERNEL)) != 0) {
2178                 if (rc == -EPIPE) {
2179                         printk("%s: Stall submitting GetMaxLUN, using 1 LUN\n",
2180                              sc->name); /* P3 */
2181                 } else {
2182                         printk(KERN_NOTICE
2183                              "%s: Unable to submit GetMaxLUN (%d)\n",
2184                              sc->name, rc);
2185                 }
2186                 goto err_submit;
2187         }
2188
2189         init_timer(&timer);
2190         timer.function = ub_probe_timeout;
2191         timer.data = (unsigned long) &compl;
2192         timer.expires = jiffies + UB_CTRL_TIMEOUT;
2193         add_timer(&timer);
2194
2195         wait_for_completion(&compl);
2196
2197         del_timer_sync(&timer);
2198         usb_kill_urb(&sc->work_urb);
2199
2200         if ((rc = sc->work_urb.status) < 0) {
2201                 if (rc == -EPIPE) {
2202                         printk("%s: Stall at GetMaxLUN, using 1 LUN\n",
2203                              sc->name); /* P3 */
2204                 } else {
2205                         printk(KERN_NOTICE
2206                              "%s: Error at GetMaxLUN (%d)\n",
2207                              sc->name, rc);
2208                 }
2209                 goto err_io;
2210         }
2211
2212         if (sc->work_urb.actual_length != 1) {
2213                 printk("%s: GetMaxLUN returned %d bytes\n", sc->name,
2214                     sc->work_urb.actual_length); /* P3 */
2215                 nluns = 0;
2216         } else {
2217                 if ((nluns = *p) == 55) {
2218                         nluns = 0;
2219                 } else {
2220                         /* GetMaxLUN returns the maximum LUN number */
2221                         nluns += 1;
2222                         if (nluns > UB_MAX_LUNS)
2223                                 nluns = UB_MAX_LUNS;
2224                 }
2225                 printk("%s: GetMaxLUN returned %d, using %d LUNs\n", sc->name,
2226                     *p, nluns); /* P3 */
2227         }
2228
2229         kfree(p);
2230         return nluns;
2231
2232 err_io:
2233 err_submit:
2234         kfree(p);
2235 err_alloc:
2236         return rc;
2237 }
2238
2239 /*
2240  * Clear initial stalls.
2241  */
2242 static int ub_probe_clear_stall(struct ub_dev *sc, int stalled_pipe)
2243 {
2244         int endp;
2245         struct usb_ctrlrequest *cr;
2246         struct completion compl;
2247         struct timer_list timer;
2248         int rc;
2249
2250         init_completion(&compl);
2251
2252         endp = usb_pipeendpoint(stalled_pipe);
2253         if (usb_pipein (stalled_pipe))
2254                 endp |= USB_DIR_IN;
2255
2256         cr = &sc->work_cr;
2257         cr->bRequestType = USB_RECIP_ENDPOINT;
2258         cr->bRequest = USB_REQ_CLEAR_FEATURE;
2259         cr->wValue = cpu_to_le16(USB_ENDPOINT_HALT);
2260         cr->wIndex = cpu_to_le16(endp);
2261         cr->wLength = cpu_to_le16(0);
2262
2263         usb_fill_control_urb(&sc->work_urb, sc->dev, sc->send_ctrl_pipe,
2264             (unsigned char*) cr, NULL, 0, ub_probe_urb_complete, &compl);
2265         sc->work_urb.actual_length = 0;
2266         sc->work_urb.error_count = 0;
2267         sc->work_urb.status = 0;
2268
2269         if ((rc = usb_submit_urb(&sc->work_urb, GFP_KERNEL)) != 0) {
2270                 printk(KERN_WARNING
2271                      "%s: Unable to submit a probe clear (%d)\n", sc->name, rc);
2272                 return rc;
2273         }
2274
2275         init_timer(&timer);
2276         timer.function = ub_probe_timeout;
2277         timer.data = (unsigned long) &compl;
2278         timer.expires = jiffies + UB_CTRL_TIMEOUT;
2279         add_timer(&timer);
2280
2281         wait_for_completion(&compl);
2282
2283         del_timer_sync(&timer);
2284         usb_kill_urb(&sc->work_urb);
2285
2286         /* reset the endpoint toggle */
2287         usb_settoggle(sc->dev, endp, usb_pipeout(sc->last_pipe), 0);
2288
2289         return 0;
2290 }
2291
2292 /*
2293  * Get the pipe settings.
2294  */
2295 static int ub_get_pipes(struct ub_dev *sc, struct usb_device *dev,
2296     struct usb_interface *intf)
2297 {
2298         struct usb_host_interface *altsetting = intf->cur_altsetting;
2299         struct usb_endpoint_descriptor *ep_in = NULL;
2300         struct usb_endpoint_descriptor *ep_out = NULL;
2301         struct usb_endpoint_descriptor *ep;
2302         int i;
2303
2304         /*
2305          * Find the endpoints we need.
2306          * We are expecting a minimum of 2 endpoints - in and out (bulk).
2307          * We will ignore any others.
2308          */
2309         for (i = 0; i < altsetting->desc.bNumEndpoints; i++) {
2310                 ep = &altsetting->endpoint[i].desc;
2311
2312                 /* Is it a BULK endpoint? */
2313                 if ((ep->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
2314                                 == USB_ENDPOINT_XFER_BULK) {
2315                         /* BULK in or out? */
2316                         if (ep->bEndpointAddress & USB_DIR_IN)
2317                                 ep_in = ep;
2318                         else
2319                                 ep_out = ep;
2320                 }
2321         }
2322
2323         if (ep_in == NULL || ep_out == NULL) {
2324                 printk(KERN_NOTICE "%s: failed endpoint check\n",
2325                     sc->name);
2326                 return -ENODEV;
2327         }
2328
2329         /* Calculate and store the pipe values */
2330         sc->send_ctrl_pipe = usb_sndctrlpipe(dev, 0);
2331         sc->recv_ctrl_pipe = usb_rcvctrlpipe(dev, 0);
2332         sc->send_bulk_pipe = usb_sndbulkpipe(dev,
2333                 ep_out->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
2334         sc->recv_bulk_pipe = usb_rcvbulkpipe(dev,
2335                 ep_in->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
2336
2337         return 0;
2338 }
2339
2340 /*
2341  * Probing is done in the process context, which allows us to cheat
2342  * and not to build a state machine for the discovery.
2343  */
2344 static int ub_probe(struct usb_interface *intf,
2345     const struct usb_device_id *dev_id)
2346 {
2347         struct ub_dev *sc;
2348         int nluns;
2349         int rc;
2350         int i;
2351
2352         if (usb_usual_check_type(dev_id, USB_US_TYPE_UB))
2353                 return -ENXIO;
2354
2355         rc = -ENOMEM;
2356         if ((sc = kmalloc(sizeof(struct ub_dev), GFP_KERNEL)) == NULL)
2357                 goto err_core;
2358         memset(sc, 0, sizeof(struct ub_dev));
2359         sc->lock = ub_next_lock();
2360         INIT_LIST_HEAD(&sc->luns);
2361         usb_init_urb(&sc->work_urb);
2362         tasklet_init(&sc->tasklet, ub_scsi_action, (unsigned long)sc);
2363         atomic_set(&sc->poison, 0);
2364         INIT_WORK(&sc->reset_work, ub_reset_task, sc);
2365         init_waitqueue_head(&sc->reset_wait);
2366
2367         init_timer(&sc->work_timer);
2368         sc->work_timer.data = (unsigned long) sc;
2369         sc->work_timer.function = ub_urb_timeout;
2370
2371         ub_init_completion(&sc->work_done);
2372         sc->work_done.done = 1;         /* A little yuk, but oh well... */
2373
2374         sc->dev = interface_to_usbdev(intf);
2375         sc->intf = intf;
2376         // sc->ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
2377         usb_set_intfdata(intf, sc);
2378         usb_get_dev(sc->dev);
2379         // usb_get_intf(sc->intf);      /* Do we need this? */
2380
2381         snprintf(sc->name, 12, DRV_NAME "(%d.%d)",
2382             sc->dev->bus->busnum, sc->dev->devnum);
2383
2384         /* XXX Verify that we can handle the device (from descriptors) */
2385
2386         if (ub_get_pipes(sc, sc->dev, intf) != 0)
2387                 goto err_dev_desc;
2388
2389         if (device_create_file(&sc->intf->dev, &dev_attr_diag) != 0)
2390                 goto err_diag;
2391
2392         /*
2393          * At this point, all USB initialization is done, do upper layer.
2394          * We really hate halfway initialized structures, so from the
2395          * invariants perspective, this ub_dev is fully constructed at
2396          * this point.
2397          */
2398
2399         /*
2400          * This is needed to clear toggles. It is a problem only if we do
2401          * `rmmod ub && modprobe ub` without disconnects, but we like that.
2402          */
2403 #if 0 /* iPod Mini fails if we do this (big white iPod works) */
2404         ub_probe_clear_stall(sc, sc->recv_bulk_pipe);
2405         ub_probe_clear_stall(sc, sc->send_bulk_pipe);
2406 #endif
2407
2408         /*
2409          * The way this is used by the startup code is a little specific.
2410          * A SCSI check causes a USB stall. Our common case code sees it
2411          * and clears the check, after which the device is ready for use.
2412          * But if a check was not present, any command other than
2413          * TEST_UNIT_READY ends with a lockup (including REQUEST_SENSE).
2414          *
2415          * If we neglect to clear the SCSI check, the first real command fails
2416          * (which is the capacity readout). We clear that and retry, but why
2417          * causing spurious retries for no reason.
2418          *
2419          * Revalidation may start with its own TEST_UNIT_READY, but that one
2420          * has to succeed, so we clear checks with an additional one here.
2421          * In any case it's not our business how revaliadation is implemented.
2422          */
2423         for (i = 0; i < 3; i++) {       /* Retries for benh's key */
2424                 if ((rc = ub_sync_tur(sc, NULL)) <= 0) break;
2425                 if (rc != 0x6) break;
2426                 msleep(10);
2427         }
2428
2429         nluns = 1;
2430         for (i = 0; i < 3; i++) {
2431                 if ((rc = ub_sync_getmaxlun(sc)) < 0) {
2432                         /*
2433                          * This segment is taken from usb-storage. They say
2434                          * that ZIP-100 needs this, but my own ZIP-100 works
2435                          * fine without this.
2436                          * Still, it does not seem to hurt anything.
2437                          */
2438                         if (rc == -EPIPE) {
2439                                 ub_probe_clear_stall(sc, sc->recv_bulk_pipe);
2440                                 ub_probe_clear_stall(sc, sc->send_bulk_pipe);
2441                         }
2442                         break;
2443                 }
2444                 if (rc != 0) {
2445                         nluns = rc;
2446                         break;
2447                 }
2448                 msleep(100);
2449         }
2450
2451         for (i = 0; i < nluns; i++) {
2452                 ub_probe_lun(sc, i);
2453         }
2454         return 0;
2455
2456         /* device_remove_file(&sc->intf->dev, &dev_attr_diag); */
2457 err_diag:
2458 err_dev_desc:
2459         usb_set_intfdata(intf, NULL);
2460         // usb_put_intf(sc->intf);
2461         usb_put_dev(sc->dev);
2462         kfree(sc);
2463 err_core:
2464         return rc;
2465 }
2466
2467 static int ub_probe_lun(struct ub_dev *sc, int lnum)
2468 {
2469         struct ub_lun *lun;
2470         request_queue_t *q;
2471         struct gendisk *disk;
2472         int rc;
2473
2474         rc = -ENOMEM;
2475         if ((lun = kmalloc(sizeof(struct ub_lun), GFP_KERNEL)) == NULL)
2476                 goto err_alloc;
2477         memset(lun, 0, sizeof(struct ub_lun));
2478         lun->num = lnum;
2479
2480         rc = -ENOSR;
2481         if ((lun->id = ub_id_get()) == -1)
2482                 goto err_id;
2483
2484         lun->udev = sc;
2485         list_add(&lun->link, &sc->luns);
2486
2487         snprintf(lun->name, 16, DRV_NAME "%c(%d.%d.%d)",
2488             lun->id + 'a', sc->dev->bus->busnum, sc->dev->devnum, lun->num);
2489
2490         lun->removable = 1;             /* XXX Query this from the device */
2491         lun->changed = 1;               /* ub_revalidate clears only */
2492         lun->first_open = 1;
2493         ub_revalidate(sc, lun);
2494
2495         rc = -ENOMEM;
2496         if ((disk = alloc_disk(UB_PARTS_PER_LUN)) == NULL)
2497                 goto err_diskalloc;
2498
2499         lun->disk = disk;
2500         sprintf(disk->disk_name, DRV_NAME "%c", lun->id + 'a');
2501         sprintf(disk->devfs_name, DEVFS_NAME "/%c", lun->id + 'a');
2502         disk->major = UB_MAJOR;
2503         disk->first_minor = lun->id * UB_PARTS_PER_LUN;
2504         disk->fops = &ub_bd_fops;
2505         disk->private_data = lun;
2506         disk->driverfs_dev = &sc->intf->dev;
2507
2508         rc = -ENOMEM;
2509         if ((q = blk_init_queue(ub_request_fn, sc->lock)) == NULL)
2510                 goto err_blkqinit;
2511
2512         disk->queue = q;
2513
2514         blk_queue_bounce_limit(q, BLK_BOUNCE_HIGH);
2515         blk_queue_max_hw_segments(q, UB_MAX_REQ_SG);
2516         blk_queue_max_phys_segments(q, UB_MAX_REQ_SG);
2517         blk_queue_segment_boundary(q, 0xffffffff);      /* Dubious. */
2518         blk_queue_max_sectors(q, UB_MAX_SECTORS);
2519         blk_queue_hardsect_size(q, lun->capacity.bsize);
2520
2521         q->queuedata = lun;
2522
2523         set_capacity(disk, lun->capacity.nsec);
2524         if (lun->removable)
2525                 disk->flags |= GENHD_FL_REMOVABLE;
2526
2527         add_disk(disk);
2528
2529         return 0;
2530
2531 err_blkqinit:
2532         put_disk(disk);
2533 err_diskalloc:
2534         list_del(&lun->link);
2535         ub_id_put(lun->id);
2536 err_id:
2537         kfree(lun);
2538 err_alloc:
2539         return rc;
2540 }
2541
2542 static void ub_disconnect(struct usb_interface *intf)
2543 {
2544         struct ub_dev *sc = usb_get_intfdata(intf);
2545         struct list_head *p;
2546         struct ub_lun *lun;
2547         struct gendisk *disk;
2548         unsigned long flags;
2549
2550         /*
2551          * Prevent ub_bd_release from pulling the rug from under us.
2552          * XXX This is starting to look like a kref.
2553          * XXX Why not to take this ref at probe time?
2554          */
2555         spin_lock_irqsave(&ub_lock, flags);
2556         sc->openc++;
2557         spin_unlock_irqrestore(&ub_lock, flags);
2558
2559         /*
2560          * Fence stall clearnings, operations triggered by unlinkings and so on.
2561          * We do not attempt to unlink any URBs, because we do not trust the
2562          * unlink paths in HC drivers. Also, we get -84 upon disconnect anyway.
2563          */
2564         atomic_set(&sc->poison, 1);
2565
2566         /*
2567          * Wait for reset to end, if any.
2568          */
2569         wait_event(sc->reset_wait, !sc->reset);
2570
2571         /*
2572          * Blow away queued commands.
2573          *
2574          * Actually, this never works, because before we get here
2575          * the HCD terminates outstanding URB(s). It causes our
2576          * SCSI command queue to advance, commands fail to submit,
2577          * and the whole queue drains. So, we just use this code to
2578          * print warnings.
2579          */
2580         spin_lock_irqsave(sc->lock, flags);
2581         {
2582                 struct ub_scsi_cmd *cmd;
2583                 int cnt = 0;
2584                 while ((cmd = ub_cmdq_peek(sc)) != NULL) {
2585                         cmd->error = -ENOTCONN;
2586                         cmd->state = UB_CMDST_DONE;
2587                         ub_cmdtr_state(sc, cmd);
2588                         ub_cmdq_pop(sc);
2589                         (*cmd->done)(sc, cmd);
2590                         cnt++;
2591                 }
2592                 if (cnt != 0) {
2593                         printk(KERN_WARNING "%s: "
2594                             "%d was queued after shutdown\n", sc->name, cnt);
2595                 }
2596         }
2597         spin_unlock_irqrestore(sc->lock, flags);
2598
2599         /*
2600          * Unregister the upper layer.
2601          */
2602         list_for_each (p, &sc->luns) {
2603                 lun = list_entry(p, struct ub_lun, link);
2604                 disk = lun->disk;
2605                 if (disk->flags & GENHD_FL_UP)
2606                         del_gendisk(disk);
2607                 /*
2608                  * I wish I could do:
2609                  *    set_bit(QUEUE_FLAG_DEAD, &q->queue_flags);
2610                  * As it is, we rely on our internal poisoning and let
2611                  * the upper levels to spin furiously failing all the I/O.
2612                  */
2613         }
2614
2615         /*
2616          * Testing for -EINPROGRESS is always a bug, so we are bending
2617          * the rules a little.
2618          */
2619         spin_lock_irqsave(sc->lock, flags);
2620         if (sc->work_urb.status == -EINPROGRESS) {      /* janitors: ignore */
2621                 printk(KERN_WARNING "%s: "
2622                     "URB is active after disconnect\n", sc->name);
2623         }
2624         spin_unlock_irqrestore(sc->lock, flags);
2625
2626         /*
2627          * There is virtually no chance that other CPU runs times so long
2628          * after ub_urb_complete should have called del_timer, but only if HCD
2629          * didn't forget to deliver a callback on unlink.
2630          */
2631         del_timer_sync(&sc->work_timer);
2632
2633         /*
2634          * At this point there must be no commands coming from anyone
2635          * and no URBs left in transit.
2636          */
2637
2638         device_remove_file(&sc->intf->dev, &dev_attr_diag);
2639         usb_set_intfdata(intf, NULL);
2640         // usb_put_intf(sc->intf);
2641         sc->intf = NULL;
2642         usb_put_dev(sc->dev);
2643         sc->dev = NULL;
2644
2645         ub_put(sc);
2646 }
2647
2648 static struct usb_driver ub_driver = {
2649         .name =         "ub",
2650         .probe =        ub_probe,
2651         .disconnect =   ub_disconnect,
2652         .id_table =     ub_usb_ids,
2653 };
2654
2655 static int __init ub_init(void)
2656 {
2657         int rc;
2658         int i;
2659
2660         for (i = 0; i < UB_QLOCK_NUM; i++)
2661                 spin_lock_init(&ub_qlockv[i]);
2662
2663         if ((rc = register_blkdev(UB_MAJOR, DRV_NAME)) != 0)
2664                 goto err_regblkdev;
2665         devfs_mk_dir(DEVFS_NAME);
2666
2667         if ((rc = usb_register(&ub_driver)) != 0)
2668                 goto err_register;
2669
2670         usb_usual_set_present(USB_US_TYPE_UB);
2671         return 0;
2672
2673 err_register:
2674         devfs_remove(DEVFS_NAME);
2675         unregister_blkdev(UB_MAJOR, DRV_NAME);
2676 err_regblkdev:
2677         return rc;
2678 }
2679
2680 static void __exit ub_exit(void)
2681 {
2682         usb_deregister(&ub_driver);
2683
2684         devfs_remove(DEVFS_NAME);
2685         unregister_blkdev(UB_MAJOR, DRV_NAME);
2686         usb_usual_clear_present(USB_US_TYPE_UB);
2687 }
2688
2689 module_init(ub_init);
2690 module_exit(ub_exit);
2691
2692 MODULE_LICENSE("GPL");