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         usb_unlink_urb(&sc->work_urb);
1110         spin_unlock_irqrestore(sc->lock, flags);
1111 }
1112
1113 /*
1114  * Completion routine for the work URB.
1115  *
1116  * This can be called directly from usb_submit_urb (while we have
1117  * the sc->lock taken) and from an interrupt (while we do NOT have
1118  * the sc->lock taken). Therefore, bounce this off to a tasklet.
1119  */
1120 static void ub_urb_complete(struct urb *urb, struct pt_regs *pt)
1121 {
1122         struct ub_dev *sc = urb->context;
1123
1124         ub_complete(&sc->work_done);
1125         tasklet_schedule(&sc->tasklet);
1126 }
1127
1128 static void ub_scsi_action(unsigned long _dev)
1129 {
1130         struct ub_dev *sc = (struct ub_dev *) _dev;
1131         unsigned long flags;
1132
1133         spin_lock_irqsave(sc->lock, flags);
1134         del_timer(&sc->work_timer);
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                         ub_scsi_urb_compl(sc, cmd);
1159                 }
1160         }
1161 }
1162
1163 static void ub_scsi_urb_compl(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1164 {
1165         struct urb *urb = &sc->work_urb;
1166         struct bulk_cs_wrap *bcs;
1167         int len;
1168         int rc;
1169
1170         if (atomic_read(&sc->poison)) {
1171                 ub_state_done(sc, cmd, -ENODEV);
1172                 return;
1173         }
1174
1175         if (cmd->state == UB_CMDST_CLEAR) {
1176                 if (urb->status == -EPIPE) {
1177                         /*
1178                          * STALL while clearning STALL.
1179                          * The control pipe clears itself - nothing to do.
1180                          */
1181                         printk(KERN_NOTICE "%s: stall on control pipe\n",
1182                             sc->name);
1183                         goto Bad_End;
1184                 }
1185
1186                 /*
1187                  * We ignore the result for the halt clear.
1188                  */
1189
1190                 /* reset the endpoint toggle */
1191                 usb_settoggle(sc->dev, usb_pipeendpoint(sc->last_pipe),
1192                         usb_pipeout(sc->last_pipe), 0);
1193
1194                 ub_state_sense(sc, cmd);
1195
1196         } else if (cmd->state == UB_CMDST_CLR2STS) {
1197                 if (urb->status == -EPIPE) {
1198                         printk(KERN_NOTICE "%s: stall on control pipe\n",
1199                             sc->name);
1200                         goto Bad_End;
1201                 }
1202
1203                 /*
1204                  * We ignore the result for the halt clear.
1205                  */
1206
1207                 /* reset the endpoint toggle */
1208                 usb_settoggle(sc->dev, usb_pipeendpoint(sc->last_pipe),
1209                         usb_pipeout(sc->last_pipe), 0);
1210
1211                 ub_state_stat(sc, cmd);
1212
1213         } else if (cmd->state == UB_CMDST_CLRRS) {
1214                 if (urb->status == -EPIPE) {
1215                         printk(KERN_NOTICE "%s: stall on control pipe\n",
1216                             sc->name);
1217                         goto Bad_End;
1218                 }
1219
1220                 /*
1221                  * We ignore the result for the halt clear.
1222                  */
1223
1224                 /* reset the endpoint toggle */
1225                 usb_settoggle(sc->dev, usb_pipeendpoint(sc->last_pipe),
1226                         usb_pipeout(sc->last_pipe), 0);
1227
1228                 ub_state_stat_counted(sc, cmd);
1229
1230         } else if (cmd->state == UB_CMDST_CMD) {
1231                 switch (urb->status) {
1232                 case 0:
1233                         break;
1234                 case -EOVERFLOW:
1235                         goto Bad_End;
1236                 case -EPIPE:
1237                         rc = ub_submit_clear_stall(sc, cmd, sc->last_pipe);
1238                         if (rc != 0) {
1239                                 printk(KERN_NOTICE "%s: "
1240                                     "unable to submit clear (%d)\n",
1241                                     sc->name, rc);
1242                                 /*
1243                                  * This is typically ENOMEM or some other such shit.
1244                                  * Retrying is pointless. Just do Bad End on it...
1245                                  */
1246                                 ub_state_done(sc, cmd, rc);
1247                                 return;
1248                         }
1249                         cmd->state = UB_CMDST_CLEAR;
1250                         ub_cmdtr_state(sc, cmd);
1251                         return;
1252                 case -ESHUTDOWN:        /* unplug */
1253                 case -EILSEQ:           /* unplug timeout on uhci */
1254                         ub_state_done(sc, cmd, -ENODEV);
1255                         return;
1256                 default:
1257                         goto Bad_End;
1258                 }
1259                 if (urb->actual_length != US_BULK_CB_WRAP_LEN) {
1260                         goto Bad_End;
1261                 }
1262
1263                 if (cmd->dir == UB_DIR_NONE || cmd->nsg < 1) {
1264                         ub_state_stat(sc, cmd);
1265                         return;
1266                 }
1267
1268                 // udelay(125);         // usb-storage has this
1269                 ub_data_start(sc, cmd);
1270
1271         } else if (cmd->state == UB_CMDST_DATA) {
1272                 if (urb->status == -EPIPE) {
1273                         rc = ub_submit_clear_stall(sc, cmd, sc->last_pipe);
1274                         if (rc != 0) {
1275                                 printk(KERN_NOTICE "%s: "
1276                                     "unable to submit clear (%d)\n",
1277                                     sc->name, rc);
1278                                 ub_state_done(sc, cmd, rc);
1279                                 return;
1280                         }
1281                         cmd->state = UB_CMDST_CLR2STS;
1282                         ub_cmdtr_state(sc, cmd);
1283                         return;
1284                 }
1285                 if (urb->status == -EOVERFLOW) {
1286                         /*
1287                          * A babble? Failure, but we must transfer CSW now.
1288                          */
1289                         cmd->error = -EOVERFLOW;        /* A cheap trick... */
1290                         ub_state_stat(sc, cmd);
1291                         return;
1292                 }
1293
1294                 if (cmd->dir == UB_DIR_WRITE) {
1295                         /*
1296                          * Do not continue writes in case of a failure.
1297                          * Doing so would cause sectors to be mixed up,
1298                          * which is worse than sectors lost.
1299                          *
1300                          * We must try to read the CSW, or many devices
1301                          * get confused.
1302                          */
1303                         len = urb->actual_length;
1304                         if (urb->status != 0 ||
1305                             len != cmd->sgv[cmd->current_sg].length) {
1306                                 cmd->act_len += len;
1307                                 ub_cmdtr_act_len(sc, cmd);
1308
1309                                 cmd->error = -EIO;
1310                                 ub_state_stat(sc, cmd);
1311                                 return;
1312                         }
1313
1314                 } else {
1315                         /*
1316                          * If an error occurs on read, we record it, and
1317                          * continue to fetch data in order to avoid bubble.
1318                          *
1319                          * As a small shortcut, we stop if we detect that
1320                          * a CSW mixed into data.
1321                          */
1322                         if (urb->status != 0)
1323                                 cmd->error = -EIO;
1324
1325                         len = urb->actual_length;
1326                         if (urb->status != 0 ||
1327                             len != cmd->sgv[cmd->current_sg].length) {
1328                                 if ((len & 0x1FF) == US_BULK_CS_WRAP_LEN)
1329                                         goto Bad_End;
1330                         }
1331                 }
1332
1333                 cmd->act_len += urb->actual_length;
1334                 ub_cmdtr_act_len(sc, cmd);
1335
1336                 if (++cmd->current_sg < cmd->nsg) {
1337                         ub_data_start(sc, cmd);
1338                         return;
1339                 }
1340                 ub_state_stat(sc, cmd);
1341
1342         } else if (cmd->state == UB_CMDST_STAT) {
1343                 if (urb->status == -EPIPE) {
1344                         rc = ub_submit_clear_stall(sc, cmd, sc->last_pipe);
1345                         if (rc != 0) {
1346                                 printk(KERN_NOTICE "%s: "
1347                                     "unable to submit clear (%d)\n",
1348                                     sc->name, rc);
1349                                 ub_state_done(sc, cmd, rc);
1350                                 return;
1351                         }
1352
1353                         /*
1354                          * Having a stall when getting CSW is an error, so
1355                          * make sure uppper levels are not oblivious to it.
1356                          */
1357                         cmd->error = -EIO;              /* A cheap trick... */
1358
1359                         cmd->state = UB_CMDST_CLRRS;
1360                         ub_cmdtr_state(sc, cmd);
1361                         return;
1362                 }
1363
1364                 /* Catch everything, including -EOVERFLOW and other nasties. */
1365                 if (urb->status != 0)
1366                         goto Bad_End;
1367
1368                 if (urb->actual_length == 0) {
1369                         ub_state_stat_counted(sc, cmd);
1370                         return;
1371                 }
1372
1373                 /*
1374                  * Check the returned Bulk protocol status.
1375                  * The status block has to be validated first.
1376                  */
1377
1378                 bcs = &sc->work_bcs;
1379
1380                 if (sc->signature == cpu_to_le32(0)) {
1381                         /*
1382                          * This is the first reply, so do not perform the check.
1383                          * Instead, remember the signature the device uses
1384                          * for future checks. But do not allow a nul.
1385                          */
1386                         sc->signature = bcs->Signature;
1387                         if (sc->signature == cpu_to_le32(0)) {
1388                                 ub_state_stat_counted(sc, cmd);
1389                                 return;
1390                         }
1391                 } else {
1392                         if (bcs->Signature != sc->signature) {
1393                                 ub_state_stat_counted(sc, cmd);
1394                                 return;
1395                         }
1396                 }
1397
1398                 if (bcs->Tag != cmd->tag) {
1399                         /*
1400                          * This usually happens when we disagree with the
1401                          * device's microcode about something. For instance,
1402                          * a few of them throw this after timeouts. They buffer
1403                          * commands and reply at commands we timed out before.
1404                          * Without flushing these replies we loop forever.
1405                          */
1406                         ub_state_stat_counted(sc, cmd);
1407                         return;
1408                 }
1409
1410                 len = le32_to_cpu(bcs->Residue);
1411                 if (len != cmd->len - cmd->act_len) {
1412                         /*
1413                          * It is all right to transfer less, the caller has
1414                          * to check. But it's not all right if the device
1415                          * counts disagree with our counts.
1416                          */
1417                         /* P3 */ printk("%s: resid %d len %d act %d\n",
1418                             sc->name, len, cmd->len, cmd->act_len);
1419                         goto Bad_End;
1420                 }
1421
1422                 switch (bcs->Status) {
1423                 case US_BULK_STAT_OK:
1424                         break;
1425                 case US_BULK_STAT_FAIL:
1426                         ub_state_sense(sc, cmd);
1427                         return;
1428                 case US_BULK_STAT_PHASE:
1429                         /* P3 */ printk("%s: status PHASE\n", sc->name);
1430                         goto Bad_End;
1431                 default:
1432                         printk(KERN_INFO "%s: unknown CSW status 0x%x\n",
1433                             sc->name, bcs->Status);
1434                         ub_state_done(sc, cmd, -EINVAL);
1435                         return;
1436                 }
1437
1438                 /* Not zeroing error to preserve a babble indicator */
1439                 if (cmd->error != 0) {
1440                         ub_state_sense(sc, cmd);
1441                         return;
1442                 }
1443                 cmd->state = UB_CMDST_DONE;
1444                 ub_cmdtr_state(sc, cmd);
1445                 ub_cmdq_pop(sc);
1446                 (*cmd->done)(sc, cmd);
1447
1448         } else if (cmd->state == UB_CMDST_SENSE) {
1449                 ub_state_done(sc, cmd, -EIO);
1450
1451         } else {
1452                 printk(KERN_WARNING "%s: "
1453                     "wrong command state %d\n",
1454                     sc->name, cmd->state);
1455                 ub_state_done(sc, cmd, -EINVAL);
1456                 return;
1457         }
1458         return;
1459
1460 Bad_End: /* Little Excel is dead */
1461         ub_state_done(sc, cmd, -EIO);
1462 }
1463
1464 /*
1465  * Factorization helper for the command state machine:
1466  * Initiate a data segment transfer.
1467  */
1468 static void ub_data_start(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1469 {
1470         struct scatterlist *sg = &cmd->sgv[cmd->current_sg];
1471         int pipe;
1472         int rc;
1473
1474         UB_INIT_COMPLETION(sc->work_done);
1475
1476         if (cmd->dir == UB_DIR_READ)
1477                 pipe = sc->recv_bulk_pipe;
1478         else
1479                 pipe = sc->send_bulk_pipe;
1480         sc->last_pipe = pipe;
1481         usb_fill_bulk_urb(&sc->work_urb, sc->dev, pipe,
1482             page_address(sg->page) + sg->offset, sg->length,
1483             ub_urb_complete, sc);
1484         sc->work_urb.actual_length = 0;
1485         sc->work_urb.error_count = 0;
1486         sc->work_urb.status = 0;
1487
1488         if ((rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC)) != 0) {
1489                 /* XXX Clear stalls */
1490                 ub_complete(&sc->work_done);
1491                 ub_state_done(sc, cmd, rc);
1492                 return;
1493         }
1494
1495         sc->work_timer.expires = jiffies + UB_DATA_TIMEOUT;
1496         add_timer(&sc->work_timer);
1497
1498         cmd->state = UB_CMDST_DATA;
1499         ub_cmdtr_state(sc, cmd);
1500 }
1501
1502 /*
1503  * Factorization helper for the command state machine:
1504  * Finish the command.
1505  */
1506 static void ub_state_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd, int rc)
1507 {
1508
1509         cmd->error = rc;
1510         cmd->state = UB_CMDST_DONE;
1511         ub_cmdtr_state(sc, cmd);
1512         ub_cmdq_pop(sc);
1513         (*cmd->done)(sc, cmd);
1514 }
1515
1516 /*
1517  * Factorization helper for the command state machine:
1518  * Submit a CSW read.
1519  */
1520 static int __ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1521 {
1522         int rc;
1523
1524         UB_INIT_COMPLETION(sc->work_done);
1525
1526         sc->last_pipe = sc->recv_bulk_pipe;
1527         usb_fill_bulk_urb(&sc->work_urb, sc->dev, sc->recv_bulk_pipe,
1528             &sc->work_bcs, US_BULK_CS_WRAP_LEN, ub_urb_complete, sc);
1529         sc->work_urb.actual_length = 0;
1530         sc->work_urb.error_count = 0;
1531         sc->work_urb.status = 0;
1532
1533         if ((rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC)) != 0) {
1534                 /* XXX Clear stalls */
1535                 ub_complete(&sc->work_done);
1536                 ub_state_done(sc, cmd, rc);
1537                 return -1;
1538         }
1539
1540         sc->work_timer.expires = jiffies + UB_STAT_TIMEOUT;
1541         add_timer(&sc->work_timer);
1542         return 0;
1543 }
1544
1545 /*
1546  * Factorization helper for the command state machine:
1547  * Submit a CSW read and go to STAT state.
1548  */
1549 static void ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1550 {
1551
1552         if (__ub_state_stat(sc, cmd) != 0)
1553                 return;
1554
1555         cmd->stat_count = 0;
1556         cmd->state = UB_CMDST_STAT;
1557         ub_cmdtr_state(sc, cmd);
1558 }
1559
1560 /*
1561  * Factorization helper for the command state machine:
1562  * Submit a CSW read and go to STAT state with counter (along [C] path).
1563  */
1564 static void ub_state_stat_counted(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1565 {
1566
1567         if (++cmd->stat_count >= 4) {
1568                 ub_state_sense(sc, cmd);
1569                 return;
1570         }
1571
1572         if (__ub_state_stat(sc, cmd) != 0)
1573                 return;
1574
1575         cmd->state = UB_CMDST_STAT;
1576         ub_cmdtr_state(sc, cmd);
1577 }
1578
1579 /*
1580  * Factorization helper for the command state machine:
1581  * Submit a REQUEST SENSE and go to SENSE state.
1582  */
1583 static void ub_state_sense(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1584 {
1585         struct ub_scsi_cmd *scmd;
1586         struct scatterlist *sg;
1587         int rc;
1588
1589         if (cmd->cdb[0] == REQUEST_SENSE) {
1590                 rc = -EPIPE;
1591                 goto error;
1592         }
1593
1594         scmd = &sc->top_rqs_cmd;
1595         memset(scmd, 0, sizeof(struct ub_scsi_cmd));
1596         scmd->cdb[0] = REQUEST_SENSE;
1597         scmd->cdb[4] = UB_SENSE_SIZE;
1598         scmd->cdb_len = 6;
1599         scmd->dir = UB_DIR_READ;
1600         scmd->state = UB_CMDST_INIT;
1601         scmd->nsg = 1;
1602         sg = &scmd->sgv[0];
1603         sg->page = virt_to_page(sc->top_sense);
1604         sg->offset = (unsigned long)sc->top_sense & (PAGE_SIZE-1);
1605         sg->length = UB_SENSE_SIZE;
1606         scmd->len = UB_SENSE_SIZE;
1607         scmd->lun = cmd->lun;
1608         scmd->done = ub_top_sense_done;
1609         scmd->back = cmd;
1610
1611         scmd->tag = sc->tagcnt++;
1612
1613         cmd->state = UB_CMDST_SENSE;
1614         ub_cmdtr_state(sc, cmd);
1615
1616         ub_cmdq_insert(sc, scmd);
1617         return;
1618
1619 error:
1620         ub_state_done(sc, cmd, rc);
1621 }
1622
1623 /*
1624  * A helper for the command's state machine:
1625  * Submit a stall clear.
1626  */
1627 static int ub_submit_clear_stall(struct ub_dev *sc, struct ub_scsi_cmd *cmd,
1628     int stalled_pipe)
1629 {
1630         int endp;
1631         struct usb_ctrlrequest *cr;
1632         int rc;
1633
1634         endp = usb_pipeendpoint(stalled_pipe);
1635         if (usb_pipein (stalled_pipe))
1636                 endp |= USB_DIR_IN;
1637
1638         cr = &sc->work_cr;
1639         cr->bRequestType = USB_RECIP_ENDPOINT;
1640         cr->bRequest = USB_REQ_CLEAR_FEATURE;
1641         cr->wValue = cpu_to_le16(USB_ENDPOINT_HALT);
1642         cr->wIndex = cpu_to_le16(endp);
1643         cr->wLength = cpu_to_le16(0);
1644
1645         UB_INIT_COMPLETION(sc->work_done);
1646
1647         usb_fill_control_urb(&sc->work_urb, sc->dev, sc->send_ctrl_pipe,
1648             (unsigned char*) cr, NULL, 0, ub_urb_complete, sc);
1649         sc->work_urb.actual_length = 0;
1650         sc->work_urb.error_count = 0;
1651         sc->work_urb.status = 0;
1652
1653         if ((rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC)) != 0) {
1654                 ub_complete(&sc->work_done);
1655                 return rc;
1656         }
1657
1658         sc->work_timer.expires = jiffies + UB_CTRL_TIMEOUT;
1659         add_timer(&sc->work_timer);
1660         return 0;
1661 }
1662
1663 /*
1664  */
1665 static void ub_top_sense_done(struct ub_dev *sc, struct ub_scsi_cmd *scmd)
1666 {
1667         unsigned char *sense = sc->top_sense;
1668         struct ub_scsi_cmd *cmd;
1669
1670         /*
1671          * Ignoring scmd->act_len, because the buffer was pre-zeroed.
1672          */
1673         ub_cmdtr_sense(sc, scmd, sense);
1674
1675         /*
1676          * Find the command which triggered the unit attention or a check,
1677          * save the sense into it, and advance its state machine.
1678          */
1679         if ((cmd = ub_cmdq_peek(sc)) == NULL) {
1680                 printk(KERN_WARNING "%s: sense done while idle\n", sc->name);
1681                 return;
1682         }
1683         if (cmd != scmd->back) {
1684                 printk(KERN_WARNING "%s: "
1685                     "sense done for wrong command 0x%x\n",
1686                     sc->name, cmd->tag);
1687                 return;
1688         }
1689         if (cmd->state != UB_CMDST_SENSE) {
1690                 printk(KERN_WARNING "%s: "
1691                     "sense done with bad cmd state %d\n",
1692                     sc->name, cmd->state);
1693                 return;
1694         }
1695
1696         cmd->key = sense[2] & 0x0F;
1697         cmd->asc = sense[12];
1698         cmd->ascq = sense[13];
1699
1700         ub_scsi_urb_compl(sc, cmd);
1701 }
1702
1703 /*
1704  * Reset management
1705  */
1706
1707 static void ub_reset_enter(struct ub_dev *sc)
1708 {
1709
1710         if (sc->reset) {
1711                 /* This happens often on multi-LUN devices. */
1712                 return;
1713         }
1714         sc->reset = 1;
1715
1716 #if 0 /* Not needed because the disconnect waits for us. */
1717         unsigned long flags;
1718         spin_lock_irqsave(&ub_lock, flags);
1719         sc->openc++;
1720         spin_unlock_irqrestore(&ub_lock, flags);
1721 #endif
1722
1723 #if 0 /* We let them stop themselves. */
1724         struct list_head *p;
1725         struct ub_lun *lun;
1726         list_for_each(p, &sc->luns) {
1727                 lun = list_entry(p, struct ub_lun, link);
1728                 blk_stop_queue(lun->disk->queue);
1729         }
1730 #endif
1731
1732         schedule_work(&sc->reset_work);
1733 }
1734
1735 static void ub_reset_task(void *arg)
1736 {
1737         struct ub_dev *sc = arg;
1738         unsigned long flags;
1739         struct list_head *p;
1740         struct ub_lun *lun;
1741         int lkr, rc;
1742
1743         if (!sc->reset) {
1744                 printk(KERN_WARNING "%s: Running reset unrequested\n",
1745                     sc->name);
1746                 return;
1747         }
1748
1749         if (atomic_read(&sc->poison)) {
1750                 printk(KERN_NOTICE "%s: Not resetting disconnected device\n",
1751                     sc->name); /* P3 This floods. Remove soon. XXX */
1752         } else if (sc->dev->actconfig->desc.bNumInterfaces != 1) {
1753                 printk(KERN_NOTICE "%s: Not resetting multi-interface device\n",
1754                     sc->name); /* P3 This floods. Remove soon. XXX */
1755         } else {
1756                 if ((lkr = usb_lock_device_for_reset(sc->dev, sc->intf)) < 0) {
1757                         printk(KERN_NOTICE
1758                             "%s: usb_lock_device_for_reset failed (%d)\n",
1759                             sc->name, lkr);
1760                 } else {
1761                         rc = usb_reset_device(sc->dev);
1762                         if (rc < 0) {
1763                                 printk(KERN_NOTICE "%s: "
1764                                     "usb_lock_device_for_reset failed (%d)\n",
1765                                     sc->name, rc);
1766                         }
1767
1768                         if (lkr)
1769                                 usb_unlock_device(sc->dev);
1770                 }
1771         }
1772
1773         /*
1774          * In theory, no commands can be running while reset is active,
1775          * so nobody can ask for another reset, and so we do not need any
1776          * queues of resets or anything. We do need a spinlock though,
1777          * to interact with block layer.
1778          */
1779         spin_lock_irqsave(sc->lock, flags);
1780         sc->reset = 0;
1781         tasklet_schedule(&sc->tasklet);
1782         list_for_each(p, &sc->luns) {
1783                 lun = list_entry(p, struct ub_lun, link);
1784                 blk_start_queue(lun->disk->queue);
1785         }
1786         wake_up(&sc->reset_wait);
1787         spin_unlock_irqrestore(sc->lock, flags);
1788 }
1789
1790 /*
1791  * This is called from a process context.
1792  */
1793 static void ub_revalidate(struct ub_dev *sc, struct ub_lun *lun)
1794 {
1795
1796         lun->readonly = 0;      /* XXX Query this from the device */
1797
1798         lun->capacity.nsec = 0;
1799         lun->capacity.bsize = 512;
1800         lun->capacity.bshift = 0;
1801
1802         if (ub_sync_tur(sc, lun) != 0)
1803                 return;                 /* Not ready */
1804         lun->changed = 0;
1805
1806         if (ub_sync_read_cap(sc, lun, &lun->capacity) != 0) {
1807                 /*
1808                  * The retry here means something is wrong, either with the
1809                  * device, with the transport, or with our code.
1810                  * We keep this because sd.c has retries for capacity.
1811                  */
1812                 if (ub_sync_read_cap(sc, lun, &lun->capacity) != 0) {
1813                         lun->capacity.nsec = 0;
1814                         lun->capacity.bsize = 512;
1815                         lun->capacity.bshift = 0;
1816                 }
1817         }
1818 }
1819
1820 /*
1821  * The open funcion.
1822  * This is mostly needed to keep refcounting, but also to support
1823  * media checks on removable media drives.
1824  */
1825 static int ub_bd_open(struct inode *inode, struct file *filp)
1826 {
1827         struct gendisk *disk = inode->i_bdev->bd_disk;
1828         struct ub_lun *lun;
1829         struct ub_dev *sc;
1830         unsigned long flags;
1831         int rc;
1832
1833         if ((lun = disk->private_data) == NULL)
1834                 return -ENXIO;
1835         sc = lun->udev;
1836
1837         spin_lock_irqsave(&ub_lock, flags);
1838         if (atomic_read(&sc->poison)) {
1839                 spin_unlock_irqrestore(&ub_lock, flags);
1840                 return -ENXIO;
1841         }
1842         sc->openc++;
1843         spin_unlock_irqrestore(&ub_lock, flags);
1844
1845         /*
1846          * This is a workaround for a specific problem in our block layer.
1847          * In 2.6.9, register_disk duplicates the code from rescan_partitions.
1848          * However, if we do add_disk with a device which persistently reports
1849          * a changed media, add_disk calls register_disk, which does do_open,
1850          * which will call rescan_paritions for changed media. After that,
1851          * register_disk attempts to do it all again and causes double kobject
1852          * registration and a eventually an oops on module removal.
1853          *
1854          * The bottom line is, Al Viro says that we should not allow
1855          * bdev->bd_invalidated to be set when doing add_disk no matter what.
1856          */
1857         if (lun->first_open) {
1858                 lun->first_open = 0;
1859                 if (lun->changed) {
1860                         rc = -ENOMEDIUM;
1861                         goto err_open;
1862                 }
1863         }
1864
1865         if (lun->removable || lun->readonly)
1866                 check_disk_change(inode->i_bdev);
1867
1868         /*
1869          * The sd.c considers ->media_present and ->changed not equivalent,
1870          * under some pretty murky conditions (a failure of READ CAPACITY).
1871          * We may need it one day.
1872          */
1873         if (lun->removable && lun->changed && !(filp->f_flags & O_NDELAY)) {
1874                 rc = -ENOMEDIUM;
1875                 goto err_open;
1876         }
1877
1878         if (lun->readonly && (filp->f_mode & FMODE_WRITE)) {
1879                 rc = -EROFS;
1880                 goto err_open;
1881         }
1882
1883         return 0;
1884
1885 err_open:
1886         ub_put(sc);
1887         return rc;
1888 }
1889
1890 /*
1891  */
1892 static int ub_bd_release(struct inode *inode, struct file *filp)
1893 {
1894         struct gendisk *disk = inode->i_bdev->bd_disk;
1895         struct ub_lun *lun = disk->private_data;
1896         struct ub_dev *sc = lun->udev;
1897
1898         ub_put(sc);
1899         return 0;
1900 }
1901
1902 /*
1903  * The ioctl interface.
1904  */
1905 static int ub_bd_ioctl(struct inode *inode, struct file *filp,
1906     unsigned int cmd, unsigned long arg)
1907 {
1908         struct gendisk *disk = inode->i_bdev->bd_disk;
1909         void __user *usermem = (void __user *) arg;
1910
1911         return scsi_cmd_ioctl(filp, disk, cmd, usermem);
1912 }
1913
1914 /*
1915  * This is called once a new disk was seen by the block layer or by ub_probe().
1916  * The main onjective here is to discover the features of the media such as
1917  * the capacity, read-only status, etc. USB storage generally does not
1918  * need to be spun up, but if we needed it, this would be the place.
1919  *
1920  * This call can sleep.
1921  *
1922  * The return code is not used.
1923  */
1924 static int ub_bd_revalidate(struct gendisk *disk)
1925 {
1926         struct ub_lun *lun = disk->private_data;
1927
1928         ub_revalidate(lun->udev, lun);
1929
1930         /* XXX Support sector size switching like in sr.c */
1931         blk_queue_hardsect_size(disk->queue, lun->capacity.bsize);
1932         set_capacity(disk, lun->capacity.nsec);
1933         // set_disk_ro(sdkp->disk, lun->readonly);
1934
1935         return 0;
1936 }
1937
1938 /*
1939  * The check is called by the block layer to verify if the media
1940  * is still available. It is supposed to be harmless, lightweight and
1941  * non-intrusive in case the media was not changed.
1942  *
1943  * This call can sleep.
1944  *
1945  * The return code is bool!
1946  */
1947 static int ub_bd_media_changed(struct gendisk *disk)
1948 {
1949         struct ub_lun *lun = disk->private_data;
1950
1951         if (!lun->removable)
1952                 return 0;
1953
1954         /*
1955          * We clean checks always after every command, so this is not
1956          * as dangerous as it looks. If the TEST_UNIT_READY fails here,
1957          * the device is actually not ready with operator or software
1958          * intervention required. One dangerous item might be a drive which
1959          * spins itself down, and come the time to write dirty pages, this
1960          * will fail, then block layer discards the data. Since we never
1961          * spin drives up, such devices simply cannot be used with ub anyway.
1962          */
1963         if (ub_sync_tur(lun->udev, lun) != 0) {
1964                 lun->changed = 1;
1965                 return 1;
1966         }
1967
1968         return lun->changed;
1969 }
1970
1971 static struct block_device_operations ub_bd_fops = {
1972         .owner          = THIS_MODULE,
1973         .open           = ub_bd_open,
1974         .release        = ub_bd_release,
1975         .ioctl          = ub_bd_ioctl,
1976         .media_changed  = ub_bd_media_changed,
1977         .revalidate_disk = ub_bd_revalidate,
1978 };
1979
1980 /*
1981  * Common ->done routine for commands executed synchronously.
1982  */
1983 static void ub_probe_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
1984 {
1985         struct completion *cop = cmd->back;
1986         complete(cop);
1987 }
1988
1989 /*
1990  * Test if the device has a check condition on it, synchronously.
1991  */
1992 static int ub_sync_tur(struct ub_dev *sc, struct ub_lun *lun)
1993 {
1994         struct ub_scsi_cmd *cmd;
1995         enum { ALLOC_SIZE = sizeof(struct ub_scsi_cmd) };
1996         unsigned long flags;
1997         struct completion compl;
1998         int rc;
1999
2000         init_completion(&compl);
2001
2002         rc = -ENOMEM;
2003         if ((cmd = kmalloc(ALLOC_SIZE, GFP_KERNEL)) == NULL)
2004                 goto err_alloc;
2005         memset(cmd, 0, ALLOC_SIZE);
2006
2007         cmd->cdb[0] = TEST_UNIT_READY;
2008         cmd->cdb_len = 6;
2009         cmd->dir = UB_DIR_NONE;
2010         cmd->state = UB_CMDST_INIT;
2011         cmd->lun = lun;                 /* This may be NULL, but that's ok */
2012         cmd->done = ub_probe_done;
2013         cmd->back = &compl;
2014
2015         spin_lock_irqsave(sc->lock, flags);
2016         cmd->tag = sc->tagcnt++;
2017
2018         rc = ub_submit_scsi(sc, cmd);
2019         spin_unlock_irqrestore(sc->lock, flags);
2020
2021         if (rc != 0) {
2022                 printk("ub: testing ready: submit error (%d)\n", rc); /* P3 */
2023                 goto err_submit;
2024         }
2025
2026         wait_for_completion(&compl);
2027
2028         rc = cmd->error;
2029
2030         if (rc == -EIO && cmd->key != 0)        /* Retries for benh's key */
2031                 rc = cmd->key;
2032
2033 err_submit:
2034         kfree(cmd);
2035 err_alloc:
2036         return rc;
2037 }
2038
2039 /*
2040  * Read the SCSI capacity synchronously (for probing).
2041  */
2042 static int ub_sync_read_cap(struct ub_dev *sc, struct ub_lun *lun,
2043     struct ub_capacity *ret)
2044 {
2045         struct ub_scsi_cmd *cmd;
2046         struct scatterlist *sg;
2047         char *p;
2048         enum { ALLOC_SIZE = sizeof(struct ub_scsi_cmd) + 8 };
2049         unsigned long flags;
2050         unsigned int bsize, shift;
2051         unsigned long nsec;
2052         struct completion compl;
2053         int rc;
2054
2055         init_completion(&compl);
2056
2057         rc = -ENOMEM;
2058         if ((cmd = kmalloc(ALLOC_SIZE, GFP_KERNEL)) == NULL)
2059                 goto err_alloc;
2060         memset(cmd, 0, ALLOC_SIZE);
2061         p = (char *)cmd + sizeof(struct ub_scsi_cmd);
2062
2063         cmd->cdb[0] = 0x25;
2064         cmd->cdb_len = 10;
2065         cmd->dir = UB_DIR_READ;
2066         cmd->state = UB_CMDST_INIT;
2067         cmd->nsg = 1;
2068         sg = &cmd->sgv[0];
2069         sg->page = virt_to_page(p);
2070         sg->offset = (unsigned long)p & (PAGE_SIZE-1);
2071         sg->length = 8;
2072         cmd->len = 8;
2073         cmd->lun = lun;
2074         cmd->done = ub_probe_done;
2075         cmd->back = &compl;
2076
2077         spin_lock_irqsave(sc->lock, flags);
2078         cmd->tag = sc->tagcnt++;
2079
2080         rc = ub_submit_scsi(sc, cmd);
2081         spin_unlock_irqrestore(sc->lock, flags);
2082
2083         if (rc != 0) {
2084                 printk("ub: reading capacity: submit error (%d)\n", rc); /* P3 */
2085                 goto err_submit;
2086         }
2087
2088         wait_for_completion(&compl);
2089
2090         if (cmd->error != 0) {
2091                 printk("ub: reading capacity: error %d\n", cmd->error); /* P3 */
2092                 rc = -EIO;
2093                 goto err_read;
2094         }
2095         if (cmd->act_len != 8) {
2096                 printk("ub: reading capacity: size %d\n", cmd->act_len); /* P3 */
2097                 rc = -EIO;
2098                 goto err_read;
2099         }
2100
2101         /* sd.c special-cases sector size of 0 to mean 512. Needed? Safe? */
2102         nsec = be32_to_cpu(*(__be32 *)p) + 1;
2103         bsize = be32_to_cpu(*(__be32 *)(p + 4));
2104         switch (bsize) {
2105         case 512:       shift = 0;      break;
2106         case 1024:      shift = 1;      break;
2107         case 2048:      shift = 2;      break;
2108         case 4096:      shift = 3;      break;
2109         default:
2110                 printk("ub: Bad sector size %u\n", bsize); /* P3 */
2111                 rc = -EDOM;
2112                 goto err_inv_bsize;
2113         }
2114
2115         ret->bsize = bsize;
2116         ret->bshift = shift;
2117         ret->nsec = nsec << shift;
2118         rc = 0;
2119
2120 err_inv_bsize:
2121 err_read:
2122 err_submit:
2123         kfree(cmd);
2124 err_alloc:
2125         return rc;
2126 }
2127
2128 /*
2129  */
2130 static void ub_probe_urb_complete(struct urb *urb, struct pt_regs *pt)
2131 {
2132         struct completion *cop = urb->context;
2133         complete(cop);
2134 }
2135
2136 static void ub_probe_timeout(unsigned long arg)
2137 {
2138         struct completion *cop = (struct completion *) arg;
2139         complete(cop);
2140 }
2141
2142 /*
2143  * Get number of LUNs by the way of Bulk GetMaxLUN command.
2144  */
2145 static int ub_sync_getmaxlun(struct ub_dev *sc)
2146 {
2147         int ifnum = sc->intf->cur_altsetting->desc.bInterfaceNumber;
2148         unsigned char *p;
2149         enum { ALLOC_SIZE = 1 };
2150         struct usb_ctrlrequest *cr;
2151         struct completion compl;
2152         struct timer_list timer;
2153         int nluns;
2154         int rc;
2155
2156         init_completion(&compl);
2157
2158         rc = -ENOMEM;
2159         if ((p = kmalloc(ALLOC_SIZE, GFP_KERNEL)) == NULL)
2160                 goto err_alloc;
2161         *p = 55;
2162
2163         cr = &sc->work_cr;
2164         cr->bRequestType = USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE;
2165         cr->bRequest = US_BULK_GET_MAX_LUN;
2166         cr->wValue = cpu_to_le16(0);
2167         cr->wIndex = cpu_to_le16(ifnum);
2168         cr->wLength = cpu_to_le16(1);
2169
2170         usb_fill_control_urb(&sc->work_urb, sc->dev, sc->recv_ctrl_pipe,
2171             (unsigned char*) cr, p, 1, ub_probe_urb_complete, &compl);
2172         sc->work_urb.actual_length = 0;
2173         sc->work_urb.error_count = 0;
2174         sc->work_urb.status = 0;
2175
2176         if ((rc = usb_submit_urb(&sc->work_urb, GFP_KERNEL)) != 0) {
2177                 if (rc == -EPIPE) {
2178                         printk("%s: Stall submitting GetMaxLUN, using 1 LUN\n",
2179                              sc->name); /* P3 */
2180                 } else {
2181                         printk(KERN_NOTICE
2182                              "%s: Unable to submit GetMaxLUN (%d)\n",
2183                              sc->name, rc);
2184                 }
2185                 goto err_submit;
2186         }
2187
2188         init_timer(&timer);
2189         timer.function = ub_probe_timeout;
2190         timer.data = (unsigned long) &compl;
2191         timer.expires = jiffies + UB_CTRL_TIMEOUT;
2192         add_timer(&timer);
2193
2194         wait_for_completion(&compl);
2195
2196         del_timer_sync(&timer);
2197         usb_kill_urb(&sc->work_urb);
2198
2199         if ((rc = sc->work_urb.status) < 0) {
2200                 if (rc == -EPIPE) {
2201                         printk("%s: Stall at GetMaxLUN, using 1 LUN\n",
2202                              sc->name); /* P3 */
2203                 } else {
2204                         printk(KERN_NOTICE
2205                              "%s: Error at GetMaxLUN (%d)\n",
2206                              sc->name, rc);
2207                 }
2208                 goto err_io;
2209         }
2210
2211         if (sc->work_urb.actual_length != 1) {
2212                 printk("%s: GetMaxLUN returned %d bytes\n", sc->name,
2213                     sc->work_urb.actual_length); /* P3 */
2214                 nluns = 0;
2215         } else {
2216                 if ((nluns = *p) == 55) {
2217                         nluns = 0;
2218                 } else {
2219                         /* GetMaxLUN returns the maximum LUN number */
2220                         nluns += 1;
2221                         if (nluns > UB_MAX_LUNS)
2222                                 nluns = UB_MAX_LUNS;
2223                 }
2224                 printk("%s: GetMaxLUN returned %d, using %d LUNs\n", sc->name,
2225                     *p, nluns); /* P3 */
2226         }
2227
2228         kfree(p);
2229         return nluns;
2230
2231 err_io:
2232 err_submit:
2233         kfree(p);
2234 err_alloc:
2235         return rc;
2236 }
2237
2238 /*
2239  * Clear initial stalls.
2240  */
2241 static int ub_probe_clear_stall(struct ub_dev *sc, int stalled_pipe)
2242 {
2243         int endp;
2244         struct usb_ctrlrequest *cr;
2245         struct completion compl;
2246         struct timer_list timer;
2247         int rc;
2248
2249         init_completion(&compl);
2250
2251         endp = usb_pipeendpoint(stalled_pipe);
2252         if (usb_pipein (stalled_pipe))
2253                 endp |= USB_DIR_IN;
2254
2255         cr = &sc->work_cr;
2256         cr->bRequestType = USB_RECIP_ENDPOINT;
2257         cr->bRequest = USB_REQ_CLEAR_FEATURE;
2258         cr->wValue = cpu_to_le16(USB_ENDPOINT_HALT);
2259         cr->wIndex = cpu_to_le16(endp);
2260         cr->wLength = cpu_to_le16(0);
2261
2262         usb_fill_control_urb(&sc->work_urb, sc->dev, sc->send_ctrl_pipe,
2263             (unsigned char*) cr, NULL, 0, ub_probe_urb_complete, &compl);
2264         sc->work_urb.actual_length = 0;
2265         sc->work_urb.error_count = 0;
2266         sc->work_urb.status = 0;
2267
2268         if ((rc = usb_submit_urb(&sc->work_urb, GFP_KERNEL)) != 0) {
2269                 printk(KERN_WARNING
2270                      "%s: Unable to submit a probe clear (%d)\n", sc->name, rc);
2271                 return rc;
2272         }
2273
2274         init_timer(&timer);
2275         timer.function = ub_probe_timeout;
2276         timer.data = (unsigned long) &compl;
2277         timer.expires = jiffies + UB_CTRL_TIMEOUT;
2278         add_timer(&timer);
2279
2280         wait_for_completion(&compl);
2281
2282         del_timer_sync(&timer);
2283         usb_kill_urb(&sc->work_urb);
2284
2285         /* reset the endpoint toggle */
2286         usb_settoggle(sc->dev, endp, usb_pipeout(sc->last_pipe), 0);
2287
2288         return 0;
2289 }
2290
2291 /*
2292  * Get the pipe settings.
2293  */
2294 static int ub_get_pipes(struct ub_dev *sc, struct usb_device *dev,
2295     struct usb_interface *intf)
2296 {
2297         struct usb_host_interface *altsetting = intf->cur_altsetting;
2298         struct usb_endpoint_descriptor *ep_in = NULL;
2299         struct usb_endpoint_descriptor *ep_out = NULL;
2300         struct usb_endpoint_descriptor *ep;
2301         int i;
2302
2303         /*
2304          * Find the endpoints we need.
2305          * We are expecting a minimum of 2 endpoints - in and out (bulk).
2306          * We will ignore any others.
2307          */
2308         for (i = 0; i < altsetting->desc.bNumEndpoints; i++) {
2309                 ep = &altsetting->endpoint[i].desc;
2310
2311                 /* Is it a BULK endpoint? */
2312                 if ((ep->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
2313                                 == USB_ENDPOINT_XFER_BULK) {
2314                         /* BULK in or out? */
2315                         if (ep->bEndpointAddress & USB_DIR_IN)
2316                                 ep_in = ep;
2317                         else
2318                                 ep_out = ep;
2319                 }
2320         }
2321
2322         if (ep_in == NULL || ep_out == NULL) {
2323                 printk(KERN_NOTICE "%s: failed endpoint check\n",
2324                     sc->name);
2325                 return -ENODEV;
2326         }
2327
2328         /* Calculate and store the pipe values */
2329         sc->send_ctrl_pipe = usb_sndctrlpipe(dev, 0);
2330         sc->recv_ctrl_pipe = usb_rcvctrlpipe(dev, 0);
2331         sc->send_bulk_pipe = usb_sndbulkpipe(dev,
2332                 ep_out->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
2333         sc->recv_bulk_pipe = usb_rcvbulkpipe(dev,
2334                 ep_in->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
2335
2336         return 0;
2337 }
2338
2339 /*
2340  * Probing is done in the process context, which allows us to cheat
2341  * and not to build a state machine for the discovery.
2342  */
2343 static int ub_probe(struct usb_interface *intf,
2344     const struct usb_device_id *dev_id)
2345 {
2346         struct ub_dev *sc;
2347         int nluns;
2348         int rc;
2349         int i;
2350
2351         if (usb_usual_check_type(dev_id, USB_US_TYPE_UB))
2352                 return -ENXIO;
2353
2354         rc = -ENOMEM;
2355         if ((sc = kmalloc(sizeof(struct ub_dev), GFP_KERNEL)) == NULL)
2356                 goto err_core;
2357         memset(sc, 0, sizeof(struct ub_dev));
2358         sc->lock = ub_next_lock();
2359         INIT_LIST_HEAD(&sc->luns);
2360         usb_init_urb(&sc->work_urb);
2361         tasklet_init(&sc->tasklet, ub_scsi_action, (unsigned long)sc);
2362         atomic_set(&sc->poison, 0);
2363         INIT_WORK(&sc->reset_work, ub_reset_task, sc);
2364         init_waitqueue_head(&sc->reset_wait);
2365
2366         init_timer(&sc->work_timer);
2367         sc->work_timer.data = (unsigned long) sc;
2368         sc->work_timer.function = ub_urb_timeout;
2369
2370         ub_init_completion(&sc->work_done);
2371         sc->work_done.done = 1;         /* A little yuk, but oh well... */
2372
2373         sc->dev = interface_to_usbdev(intf);
2374         sc->intf = intf;
2375         // sc->ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
2376         usb_set_intfdata(intf, sc);
2377         usb_get_dev(sc->dev);
2378         // usb_get_intf(sc->intf);      /* Do we need this? */
2379
2380         snprintf(sc->name, 12, DRV_NAME "(%d.%d)",
2381             sc->dev->bus->busnum, sc->dev->devnum);
2382
2383         /* XXX Verify that we can handle the device (from descriptors) */
2384
2385         if (ub_get_pipes(sc, sc->dev, intf) != 0)
2386                 goto err_dev_desc;
2387
2388         if (device_create_file(&sc->intf->dev, &dev_attr_diag) != 0)
2389                 goto err_diag;
2390
2391         /*
2392          * At this point, all USB initialization is done, do upper layer.
2393          * We really hate halfway initialized structures, so from the
2394          * invariants perspective, this ub_dev is fully constructed at
2395          * this point.
2396          */
2397
2398         /*
2399          * This is needed to clear toggles. It is a problem only if we do
2400          * `rmmod ub && modprobe ub` without disconnects, but we like that.
2401          */
2402 #if 0 /* iPod Mini fails if we do this (big white iPod works) */
2403         ub_probe_clear_stall(sc, sc->recv_bulk_pipe);
2404         ub_probe_clear_stall(sc, sc->send_bulk_pipe);
2405 #endif
2406
2407         /*
2408          * The way this is used by the startup code is a little specific.
2409          * A SCSI check causes a USB stall. Our common case code sees it
2410          * and clears the check, after which the device is ready for use.
2411          * But if a check was not present, any command other than
2412          * TEST_UNIT_READY ends with a lockup (including REQUEST_SENSE).
2413          *
2414          * If we neglect to clear the SCSI check, the first real command fails
2415          * (which is the capacity readout). We clear that and retry, but why
2416          * causing spurious retries for no reason.
2417          *
2418          * Revalidation may start with its own TEST_UNIT_READY, but that one
2419          * has to succeed, so we clear checks with an additional one here.
2420          * In any case it's not our business how revaliadation is implemented.
2421          */
2422         for (i = 0; i < 3; i++) {       /* Retries for benh's key */
2423                 if ((rc = ub_sync_tur(sc, NULL)) <= 0) break;
2424                 if (rc != 0x6) break;
2425                 msleep(10);
2426         }
2427
2428         nluns = 1;
2429         for (i = 0; i < 3; i++) {
2430                 if ((rc = ub_sync_getmaxlun(sc)) < 0) {
2431                         /*
2432                          * This segment is taken from usb-storage. They say
2433                          * that ZIP-100 needs this, but my own ZIP-100 works
2434                          * fine without this.
2435                          * Still, it does not seem to hurt anything.
2436                          */
2437                         if (rc == -EPIPE) {
2438                                 ub_probe_clear_stall(sc, sc->recv_bulk_pipe);
2439                                 ub_probe_clear_stall(sc, sc->send_bulk_pipe);
2440                         }
2441                         break;
2442                 }
2443                 if (rc != 0) {
2444                         nluns = rc;
2445                         break;
2446                 }
2447                 msleep(100);
2448         }
2449
2450         for (i = 0; i < nluns; i++) {
2451                 ub_probe_lun(sc, i);
2452         }
2453         return 0;
2454
2455         /* device_remove_file(&sc->intf->dev, &dev_attr_diag); */
2456 err_diag:
2457 err_dev_desc:
2458         usb_set_intfdata(intf, NULL);
2459         // usb_put_intf(sc->intf);
2460         usb_put_dev(sc->dev);
2461         kfree(sc);
2462 err_core:
2463         return rc;
2464 }
2465
2466 static int ub_probe_lun(struct ub_dev *sc, int lnum)
2467 {
2468         struct ub_lun *lun;
2469         request_queue_t *q;
2470         struct gendisk *disk;
2471         int rc;
2472
2473         rc = -ENOMEM;
2474         if ((lun = kmalloc(sizeof(struct ub_lun), GFP_KERNEL)) == NULL)
2475                 goto err_alloc;
2476         memset(lun, 0, sizeof(struct ub_lun));
2477         lun->num = lnum;
2478
2479         rc = -ENOSR;
2480         if ((lun->id = ub_id_get()) == -1)
2481                 goto err_id;
2482
2483         lun->udev = sc;
2484         list_add(&lun->link, &sc->luns);
2485
2486         snprintf(lun->name, 16, DRV_NAME "%c(%d.%d.%d)",
2487             lun->id + 'a', sc->dev->bus->busnum, sc->dev->devnum, lun->num);
2488
2489         lun->removable = 1;             /* XXX Query this from the device */
2490         lun->changed = 1;               /* ub_revalidate clears only */
2491         lun->first_open = 1;
2492         ub_revalidate(sc, lun);
2493
2494         rc = -ENOMEM;
2495         if ((disk = alloc_disk(UB_PARTS_PER_LUN)) == NULL)
2496                 goto err_diskalloc;
2497
2498         lun->disk = disk;
2499         sprintf(disk->disk_name, DRV_NAME "%c", lun->id + 'a');
2500         sprintf(disk->devfs_name, DEVFS_NAME "/%c", lun->id + 'a');
2501         disk->major = UB_MAJOR;
2502         disk->first_minor = lun->id * UB_PARTS_PER_LUN;
2503         disk->fops = &ub_bd_fops;
2504         disk->private_data = lun;
2505         disk->driverfs_dev = &sc->intf->dev;
2506
2507         rc = -ENOMEM;
2508         if ((q = blk_init_queue(ub_request_fn, sc->lock)) == NULL)
2509                 goto err_blkqinit;
2510
2511         disk->queue = q;
2512
2513         blk_queue_bounce_limit(q, BLK_BOUNCE_HIGH);
2514         blk_queue_max_hw_segments(q, UB_MAX_REQ_SG);
2515         blk_queue_max_phys_segments(q, UB_MAX_REQ_SG);
2516         blk_queue_segment_boundary(q, 0xffffffff);      /* Dubious. */
2517         blk_queue_max_sectors(q, UB_MAX_SECTORS);
2518         blk_queue_hardsect_size(q, lun->capacity.bsize);
2519
2520         q->queuedata = lun;
2521
2522         set_capacity(disk, lun->capacity.nsec);
2523         if (lun->removable)
2524                 disk->flags |= GENHD_FL_REMOVABLE;
2525
2526         add_disk(disk);
2527
2528         return 0;
2529
2530 err_blkqinit:
2531         put_disk(disk);
2532 err_diskalloc:
2533         list_del(&lun->link);
2534         ub_id_put(lun->id);
2535 err_id:
2536         kfree(lun);
2537 err_alloc:
2538         return rc;
2539 }
2540
2541 static void ub_disconnect(struct usb_interface *intf)
2542 {
2543         struct ub_dev *sc = usb_get_intfdata(intf);
2544         struct list_head *p;
2545         struct ub_lun *lun;
2546         struct gendisk *disk;
2547         unsigned long flags;
2548
2549         /*
2550          * Prevent ub_bd_release from pulling the rug from under us.
2551          * XXX This is starting to look like a kref.
2552          * XXX Why not to take this ref at probe time?
2553          */
2554         spin_lock_irqsave(&ub_lock, flags);
2555         sc->openc++;
2556         spin_unlock_irqrestore(&ub_lock, flags);
2557
2558         /*
2559          * Fence stall clearnings, operations triggered by unlinkings and so on.
2560          * We do not attempt to unlink any URBs, because we do not trust the
2561          * unlink paths in HC drivers. Also, we get -84 upon disconnect anyway.
2562          */
2563         atomic_set(&sc->poison, 1);
2564
2565         /*
2566          * Wait for reset to end, if any.
2567          */
2568         wait_event(sc->reset_wait, !sc->reset);
2569
2570         /*
2571          * Blow away queued commands.
2572          *
2573          * Actually, this never works, because before we get here
2574          * the HCD terminates outstanding URB(s). It causes our
2575          * SCSI command queue to advance, commands fail to submit,
2576          * and the whole queue drains. So, we just use this code to
2577          * print warnings.
2578          */
2579         spin_lock_irqsave(sc->lock, flags);
2580         {
2581                 struct ub_scsi_cmd *cmd;
2582                 int cnt = 0;
2583                 while ((cmd = ub_cmdq_peek(sc)) != NULL) {
2584                         cmd->error = -ENOTCONN;
2585                         cmd->state = UB_CMDST_DONE;
2586                         ub_cmdtr_state(sc, cmd);
2587                         ub_cmdq_pop(sc);
2588                         (*cmd->done)(sc, cmd);
2589                         cnt++;
2590                 }
2591                 if (cnt != 0) {
2592                         printk(KERN_WARNING "%s: "
2593                             "%d was queued after shutdown\n", sc->name, cnt);
2594                 }
2595         }
2596         spin_unlock_irqrestore(sc->lock, flags);
2597
2598         /*
2599          * Unregister the upper layer.
2600          */
2601         list_for_each (p, &sc->luns) {
2602                 lun = list_entry(p, struct ub_lun, link);
2603                 disk = lun->disk;
2604                 if (disk->flags & GENHD_FL_UP)
2605                         del_gendisk(disk);
2606                 /*
2607                  * I wish I could do:
2608                  *    set_bit(QUEUE_FLAG_DEAD, &q->queue_flags);
2609                  * As it is, we rely on our internal poisoning and let
2610                  * the upper levels to spin furiously failing all the I/O.
2611                  */
2612         }
2613
2614         /*
2615          * Testing for -EINPROGRESS is always a bug, so we are bending
2616          * the rules a little.
2617          */
2618         spin_lock_irqsave(sc->lock, flags);
2619         if (sc->work_urb.status == -EINPROGRESS) {      /* janitors: ignore */
2620                 printk(KERN_WARNING "%s: "
2621                     "URB is active after disconnect\n", sc->name);
2622         }
2623         spin_unlock_irqrestore(sc->lock, flags);
2624
2625         /*
2626          * There is virtually no chance that other CPU runs times so long
2627          * after ub_urb_complete should have called del_timer, but only if HCD
2628          * didn't forget to deliver a callback on unlink.
2629          */
2630         del_timer_sync(&sc->work_timer);
2631
2632         /*
2633          * At this point there must be no commands coming from anyone
2634          * and no URBs left in transit.
2635          */
2636
2637         device_remove_file(&sc->intf->dev, &dev_attr_diag);
2638         usb_set_intfdata(intf, NULL);
2639         // usb_put_intf(sc->intf);
2640         sc->intf = NULL;
2641         usb_put_dev(sc->dev);
2642         sc->dev = NULL;
2643
2644         ub_put(sc);
2645 }
2646
2647 static struct usb_driver ub_driver = {
2648         .name =         "ub",
2649         .probe =        ub_probe,
2650         .disconnect =   ub_disconnect,
2651         .id_table =     ub_usb_ids,
2652 };
2653
2654 static int __init ub_init(void)
2655 {
2656         int rc;
2657         int i;
2658
2659         for (i = 0; i < UB_QLOCK_NUM; i++)
2660                 spin_lock_init(&ub_qlockv[i]);
2661
2662         if ((rc = register_blkdev(UB_MAJOR, DRV_NAME)) != 0)
2663                 goto err_regblkdev;
2664         devfs_mk_dir(DEVFS_NAME);
2665
2666         if ((rc = usb_register(&ub_driver)) != 0)
2667                 goto err_register;
2668
2669         usb_usual_set_present(USB_US_TYPE_UB);
2670         return 0;
2671
2672 err_register:
2673         devfs_remove(DEVFS_NAME);
2674         unregister_blkdev(UB_MAJOR, DRV_NAME);
2675 err_regblkdev:
2676         return rc;
2677 }
2678
2679 static void __exit ub_exit(void)
2680 {
2681         usb_deregister(&ub_driver);
2682
2683         devfs_remove(DEVFS_NAME);
2684         unregister_blkdev(UB_MAJOR, DRV_NAME);
2685         usb_usual_clear_present(USB_US_TYPE_UB);
2686 }
2687
2688 module_init(ub_init);
2689 module_exit(ub_exit);
2690
2691 MODULE_LICENSE("GPL");