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