drivers/usb/storage/uas.c

   1 /*
   2  * USB Attached SCSI
   3  * Note that this is not the same as the USB Mass Storage driver
   4  *
   5  * Copyright Hans de Goede <hdegoede@redhat.com> for Red Hat, Inc. 2013 - 2016
   6  * Copyright Matthew Wilcox for Intel Corp, 2010
   7  * Copyright Sarah Sharp for Intel Corp, 2010
   8  *
   9  * Distributed under the terms of the GNU GPL, version two.
  10  */
  11
  12 #include <linux/blkdev.h>
  13 #include <linux/slab.h>
  14 #include <linux/types.h>
  15 #include <linux/module.h>
  16 #include <linux/usb.h>
  17 #include <linux/usb_usual.h>
  18 #include <linux/usb/hcd.h>
  19 #include <linux/usb/storage.h>
  20 #include <linux/usb/uas.h>
  21
  22 #include <scsi/scsi.h>
  23 #include <scsi/scsi_eh.h>
  24 #include <scsi/scsi_dbg.h>
  25 #include <scsi/scsi_cmnd.h>
  26 #include <scsi/scsi_device.h>
  27 #include <scsi/scsi_host.h>
  28 #include <scsi/scsi_tcq.h>
  29
  30 #include "uas-detect.h"
  31 #include "scsiglue.h"
  32
  33 #define MAX_CMNDS 256
  34
  35 struct uas_dev_info {
  36         struct usb_interface *intf;
  37         struct usb_device *udev;
  38         struct usb_anchor cmd_urbs;
  39         struct usb_anchor sense_urbs;
  40         struct usb_anchor data_urbs;
  41         unsigned long flags;
  42         int qdepth, resetting;
  43         unsigned cmd_pipe, status_pipe, data_in_pipe, data_out_pipe;
  44         unsigned use_streams:1;
  45         unsigned shutdown:1;
  46         struct scsi_cmnd *cmnd[MAX_CMNDS];
  47         spinlock_t lock;
  48         struct work_struct work;
  49 };
  50
  51 enum {
  52         SUBMIT_STATUS_URB       = BIT(1),
  53         ALLOC_DATA_IN_URB       = BIT(2),
  54         SUBMIT_DATA_IN_URB      = BIT(3),
  55         ALLOC_DATA_OUT_URB      = BIT(4),
  56         SUBMIT_DATA_OUT_URB     = BIT(5),
  57         ALLOC_CMD_URB           = BIT(6),
  58         SUBMIT_CMD_URB          = BIT(7),
  59         COMMAND_INFLIGHT        = BIT(8),
  60         DATA_IN_URB_INFLIGHT    = BIT(9),
  61         DATA_OUT_URB_INFLIGHT   = BIT(10),
  62         COMMAND_ABORTED         = BIT(11),
  63         IS_IN_WORK_LIST         = BIT(12),
  64 };
  65
  66 /* Overrides scsi_pointer */
  67 struct uas_cmd_info {
  68         unsigned int state;
  69         unsigned int uas_tag;
  70         struct urb *cmd_urb;
  71         struct urb *data_in_urb;
  72         struct urb *data_out_urb;
  73 };
  74
  75 /* I hate forward declarations, but I actually have a loop */
  76 static int uas_submit_urbs(struct scsi_cmnd *cmnd,
  77                                 struct uas_dev_info *devinfo);
  78 static void uas_do_work(struct work_struct *work);
  79 static int uas_try_complete(struct scsi_cmnd *cmnd, const char *caller);
  80 static void uas_free_streams(struct uas_dev_info *devinfo);
  81 static void uas_log_cmd_state(struct scsi_cmnd *cmnd, const char *prefix,
  82                                 int status);
  83
  84 static void uas_do_work(struct work_struct *work)
  85 {
  86         struct uas_dev_info *devinfo =
  87                 container_of(work, struct uas_dev_info, work);
  88         struct uas_cmd_info *cmdinfo;
  89         struct scsi_cmnd *cmnd;
  90         unsigned long flags;
  91         int i, err;
  92
  93         spin_lock_irqsave(&devinfo->lock, flags);
  94
  95         if (devinfo->resetting)
  96                 goto out;
  97
  98         for (i = 0; i < devinfo->qdepth; i++) {
  99                 if (!devinfo->cmnd[i])
 100                         continue;
 101
 102                 cmnd = devinfo->cmnd[i];
 103                 cmdinfo = (void *)&cmnd->SCp;
 104
 105                 if (!(cmdinfo->state & IS_IN_WORK_LIST))
 106                         continue;
 107
 108                 err = uas_submit_urbs(cmnd, cmnd->device->hostdata);
 109                 if (!err)
 110                         cmdinfo->state &= ~IS_IN_WORK_LIST;
 111                 else
 112                         schedule_work(&devinfo->work);
 113         }
 114 out:
 115         spin_unlock_irqrestore(&devinfo->lock, flags);
 116 }
 117
 118 static void uas_add_work(struct uas_cmd_info *cmdinfo)
 119 {
 120         struct scsi_pointer *scp = (void *)cmdinfo;
 121         struct scsi_cmnd *cmnd = container_of(scp, struct scsi_cmnd, SCp);
 122         struct uas_dev_info *devinfo = cmnd->device->hostdata;
 123
 124         lockdep_assert_held(&devinfo->lock);
 125         cmdinfo->state |= IS_IN_WORK_LIST;
 126         schedule_work(&devinfo->work);
 127 }
 128
 129 static void uas_zap_pending(struct uas_dev_info *devinfo, int result)
 130 {
 131         struct uas_cmd_info *cmdinfo;
 132         struct scsi_cmnd *cmnd;
 133         unsigned long flags;
 134         int i, err;
 135
 136         spin_lock_irqsave(&devinfo->lock, flags);
 137         for (i = 0; i < devinfo->qdepth; i++) {
 138                 if (!devinfo->cmnd[i])
 139                         continue;
 140
 141                 cmnd = devinfo->cmnd[i];
 142                 cmdinfo = (void *)&cmnd->SCp;
 143                 uas_log_cmd_state(cmnd, __func__, 0);
 144                 /* Sense urbs were killed, clear COMMAND_INFLIGHT manually */
 145                 cmdinfo->state &= ~COMMAND_INFLIGHT;
 146                 cmnd->result = result << 16;
 147                 err = uas_try_complete(cmnd, __func__);
 148                 WARN_ON(err != 0);
 149         }
 150         spin_unlock_irqrestore(&devinfo->lock, flags);
 151 }
 152
 153 static void uas_sense(struct urb *urb, struct scsi_cmnd *cmnd)
 154 {
 155         struct sense_iu *sense_iu = urb->transfer_buffer;
 156         struct scsi_device *sdev = cmnd->device;
 157
 158         if (urb->actual_length > 16) {
 159                 unsigned len = be16_to_cpup(&sense_iu->len);
 160                 if (len + 16 != urb->actual_length) {
 161                         int newlen = min(len + 16, urb->actual_length) - 16;
 162                         if (newlen < 0)
 163                                 newlen = 0;
 164                         sdev_printk(KERN_INFO, sdev, "%s: urb length %d "
 165                                 "disagrees with IU sense data length %d, "
 166                                 "using %d bytes of sense data\n", __func__,
 167                                         urb->actual_length, len, newlen);
 168                         len = newlen;
 169                 }
 170                 memcpy(cmnd->sense_buffer, sense_iu->sense, len);
 171         }
 172
 173         cmnd->result = sense_iu->status;
 174 }
 175
 176 static void uas_log_cmd_state(struct scsi_cmnd *cmnd, const char *prefix,
 177                               int status)
 178 {
 179         struct uas_cmd_info *ci = (void *)&cmnd->SCp;
 180         struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
 181
 182         scmd_printk(KERN_INFO, cmnd,
 183                     "%s %d uas-tag %d inflight:%s%s%s%s%s%s%s%s%s%s%s%s ",
 184                     prefix, status, cmdinfo->uas_tag,
 185                     (ci->state & SUBMIT_STATUS_URB)     ? " s-st"  : "",
 186                     (ci->state & ALLOC_DATA_IN_URB)     ? " a-in"  : "",
 187                     (ci->state & SUBMIT_DATA_IN_URB)    ? " s-in"  : "",
 188                     (ci->state & ALLOC_DATA_OUT_URB)    ? " a-out" : "",
 189                     (ci->state & SUBMIT_DATA_OUT_URB)   ? " s-out" : "",
 190                     (ci->state & ALLOC_CMD_URB)         ? " a-cmd" : "",
 191                     (ci->state & SUBMIT_CMD_URB)        ? " s-cmd" : "",
 192                     (ci->state & COMMAND_INFLIGHT)      ? " CMD"   : "",
 193                     (ci->state & DATA_IN_URB_INFLIGHT)  ? " IN"    : "",
 194                     (ci->state & DATA_OUT_URB_INFLIGHT) ? " OUT"   : "",
 195                     (ci->state & COMMAND_ABORTED)       ? " abort" : "",
 196                     (ci->state & IS_IN_WORK_LIST)       ? " work"  : "");
 197         scsi_print_command(cmnd);
 198 }
 199
 200 static void uas_free_unsubmitted_urbs(struct scsi_cmnd *cmnd)
 201 {
 202         struct uas_cmd_info *cmdinfo;
 203
 204         if (!cmnd)
 205                 return;
 206
 207         cmdinfo = (void *)&cmnd->SCp;
 208
 209         if (cmdinfo->state & SUBMIT_CMD_URB)
 210                 usb_free_urb(cmdinfo->cmd_urb);
 211
 212         /* data urbs may have never gotten their submit flag set */
 213         if (!(cmdinfo->state & DATA_IN_URB_INFLIGHT))
 214                 usb_free_urb(cmdinfo->data_in_urb);
 215         if (!(cmdinfo->state & DATA_OUT_URB_INFLIGHT))
 216                 usb_free_urb(cmdinfo->data_out_urb);
 217 }
 218
 219 static int uas_try_complete(struct scsi_cmnd *cmnd, const char *caller)
 220 {
 221         struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
 222         struct uas_dev_info *devinfo = (void *)cmnd->device->hostdata;
 223
 224         lockdep_assert_held(&devinfo->lock);
 225         if (cmdinfo->state & (COMMAND_INFLIGHT |
 226                               DATA_IN_URB_INFLIGHT |
 227                               DATA_OUT_URB_INFLIGHT |
 228                               COMMAND_ABORTED))
 229                 return -EBUSY;
 230         devinfo->cmnd[cmdinfo->uas_tag - 1] = NULL;
 231         uas_free_unsubmitted_urbs(cmnd);
 232         cmnd->scsi_done(cmnd);
 233         return 0;
 234 }
 235
 236 static void uas_xfer_data(struct urb *urb, struct scsi_cmnd *cmnd,
 237                           unsigned direction)
 238 {
 239         struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
 240         int err;
 241
 242         cmdinfo->state |= direction | SUBMIT_STATUS_URB;
 243         err = uas_submit_urbs(cmnd, cmnd->device->hostdata);
 244         if (err) {
 245                 uas_add_work(cmdinfo);
 246         }
 247 }
 248
 249 static bool uas_evaluate_response_iu(struct response_iu *riu, struct scsi_cmnd *cmnd)
 250 {
 251         u8 response_code = riu->response_code;
 252
 253         switch (response_code) {
 254         case RC_INCORRECT_LUN:
 255                 cmnd->result = DID_BAD_TARGET << 16;
 256                 break;
 257         case RC_TMF_SUCCEEDED:
 258                 cmnd->result = DID_OK << 16;
 259                 break;
 260         case RC_TMF_NOT_SUPPORTED:
 261                 cmnd->result = DID_TARGET_FAILURE << 16;
 262                 break;
 263         default:
 264                 uas_log_cmd_state(cmnd, "response iu", response_code);
 265                 cmnd->result = DID_ERROR << 16;
 266                 break;
 267         }
 268
 269         return response_code == RC_TMF_SUCCEEDED;
 270 }
 271
 272 static void uas_stat_cmplt(struct urb *urb)
 273 {
 274         struct iu *iu = urb->transfer_buffer;
 275         struct Scsi_Host *shost = urb->context;
 276         struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
 277         struct urb *data_in_urb = NULL;
 278         struct urb *data_out_urb = NULL;
 279         struct scsi_cmnd *cmnd;
 280         struct uas_cmd_info *cmdinfo;
 281         unsigned long flags;
 282         unsigned int idx;
 283         int status = urb->status;
 284         bool success;
 285
 286         spin_lock_irqsave(&devinfo->lock, flags);
 287
 288         if (devinfo->resetting)
 289                 goto out;
 290
 291         if (status) {
 292                 if (status != -ENOENT && status != -ECONNRESET && status != -ESHUTDOWN)
 293                         dev_err(&urb->dev->dev, "stat urb: status %d\n", status);
 294                 goto out;
 295         }
 296
 297         idx = be16_to_cpup(&iu->tag) - 1;
 298         if (idx >= MAX_CMNDS || !devinfo->cmnd[idx]) {
 299                 dev_err(&urb->dev->dev,
 300                         "stat urb: no pending cmd for uas-tag %d\n", idx + 1);
 301                 goto out;
 302         }
 303
 304         cmnd = devinfo->cmnd[idx];
 305         cmdinfo = (void *)&cmnd->SCp;
 306
 307         if (!(cmdinfo->state & COMMAND_INFLIGHT)) {
 308                 uas_log_cmd_state(cmnd, "unexpected status cmplt", 0);
 309                 goto out;
 310         }
 311
 312         switch (iu->iu_id) {
 313         case IU_ID_STATUS:
 314                 uas_sense(urb, cmnd);
 315                 if (cmnd->result != 0) {
 316                         /* cancel data transfers on error */
 317                         data_in_urb = usb_get_urb(cmdinfo->data_in_urb);
 318                         data_out_urb = usb_get_urb(cmdinfo->data_out_urb);
 319                 }
 320                 cmdinfo->state &= ~COMMAND_INFLIGHT;
 321                 uas_try_complete(cmnd, __func__);
 322                 break;
 323         case IU_ID_READ_READY:
 324                 if (!cmdinfo->data_in_urb ||
 325                                 (cmdinfo->state & DATA_IN_URB_INFLIGHT)) {
 326                         uas_log_cmd_state(cmnd, "unexpected read rdy", 0);
 327                         break;
 328                 }
 329                 uas_xfer_data(urb, cmnd, SUBMIT_DATA_IN_URB);
 330                 break;
 331         case IU_ID_WRITE_READY:
 332                 if (!cmdinfo->data_out_urb ||
 333                                 (cmdinfo->state & DATA_OUT_URB_INFLIGHT)) {
 334                         uas_log_cmd_state(cmnd, "unexpected write rdy", 0);
 335                         break;
 336                 }
 337                 uas_xfer_data(urb, cmnd, SUBMIT_DATA_OUT_URB);
 338                 break;
 339         case IU_ID_RESPONSE:
 340                 cmdinfo->state &= ~COMMAND_INFLIGHT;
 341                 success = uas_evaluate_response_iu((struct response_iu *)iu, cmnd);
 342                 if (!success) {
 343                         /* Error, cancel data transfers */
 344                         data_in_urb = usb_get_urb(cmdinfo->data_in_urb);
 345                         data_out_urb = usb_get_urb(cmdinfo->data_out_urb);
 346                 }
 347                 uas_try_complete(cmnd, __func__);
 348                 break;
 349         default:
 350                 uas_log_cmd_state(cmnd, "bogus IU", iu->iu_id);
 351         }
 352 out:
 353         usb_free_urb(urb);
 354         spin_unlock_irqrestore(&devinfo->lock, flags);
 355
 356         /* Unlinking of data urbs must be done without holding the lock */
 357         if (data_in_urb) {
 358                 usb_unlink_urb(data_in_urb);
 359                 usb_put_urb(data_in_urb);
 360         }
 361         if (data_out_urb) {
 362                 usb_unlink_urb(data_out_urb);
 363                 usb_put_urb(data_out_urb);
 364         }
 365 }
 366
 367 static void uas_data_cmplt(struct urb *urb)
 368 {
 369         struct scsi_cmnd *cmnd = urb->context;
 370         struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
 371         struct uas_dev_info *devinfo = (void *)cmnd->device->hostdata;
 372         struct scsi_data_buffer *sdb = NULL;
 373         unsigned long flags;
 374         int status = urb->status;
 375
 376         spin_lock_irqsave(&devinfo->lock, flags);
 377
 378         if (cmdinfo->data_in_urb == urb) {
 379                 sdb = scsi_in(cmnd);
 380                 cmdinfo->state &= ~DATA_IN_URB_INFLIGHT;
 381                 cmdinfo->data_in_urb = NULL;
 382         } else if (cmdinfo->data_out_urb == urb) {
 383                 sdb = scsi_out(cmnd);
 384                 cmdinfo->state &= ~DATA_OUT_URB_INFLIGHT;
 385                 cmdinfo->data_out_urb = NULL;
 386         }
 387         if (sdb == NULL) {
 388                 WARN_ON_ONCE(1);
 389                 goto out;
 390         }
 391
 392         if (devinfo->resetting)
 393                 goto out;
 394
 395         /* Data urbs should not complete before the cmd urb is submitted */
 396         if (cmdinfo->state & SUBMIT_CMD_URB) {
 397                 uas_log_cmd_state(cmnd, "unexpected data cmplt", 0);
 398                 goto out;
 399         }
 400
 401         if (status) {
 402                 if (status != -ENOENT && status != -ECONNRESET && status != -ESHUTDOWN)
 403                         uas_log_cmd_state(cmnd, "data cmplt err", status);
 404                 /* error: no data transfered */
 405                 sdb->resid = sdb->length;
 406         } else {
 407                 sdb->resid = sdb->length - urb->actual_length;
 408         }
 409         uas_try_complete(cmnd, __func__);
 410 out:
 411         usb_free_urb(urb);
 412         spin_unlock_irqrestore(&devinfo->lock, flags);
 413 }
 414
 415 static void uas_cmd_cmplt(struct urb *urb)
 416 {
 417         if (urb->status)
 418                 dev_err(&urb->dev->dev, "cmd cmplt err %d\n", urb->status);
 419
 420         usb_free_urb(urb);
 421 }
 422
 423 static struct urb *uas_alloc_data_urb(struct uas_dev_info *devinfo, gfp_t gfp,
 424                                       struct scsi_cmnd *cmnd,
 425                                       enum dma_data_direction dir)
 426 {
 427         struct usb_device *udev = devinfo->udev;
 428         struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
 429         struct urb *urb = usb_alloc_urb(0, gfp);
 430         struct scsi_data_buffer *sdb = (dir == DMA_FROM_DEVICE)
 431                 ? scsi_in(cmnd) : scsi_out(cmnd);
 432         unsigned int pipe = (dir == DMA_FROM_DEVICE)
 433                 ? devinfo->data_in_pipe : devinfo->data_out_pipe;
 434
 435         if (!urb)
 436                 goto out;
 437         usb_fill_bulk_urb(urb, udev, pipe, NULL, sdb->length,
 438                           uas_data_cmplt, cmnd);
 439         if (devinfo->use_streams)
 440                 urb->stream_id = cmdinfo->uas_tag;
 441         urb->num_sgs = udev->bus->sg_tablesize ? sdb->table.nents : 0;
 442         urb->sg = sdb->table.sgl;
 443  out:
 444         return urb;
 445 }
 446
 447 static struct urb *uas_alloc_sense_urb(struct uas_dev_info *devinfo, gfp_t gfp,
 448                                        struct scsi_cmnd *cmnd)
 449 {
 450         struct usb_device *udev = devinfo->udev;
 451         struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
 452         struct urb *urb = usb_alloc_urb(0, gfp);
 453         struct sense_iu *iu;
 454
 455         if (!urb)
 456                 goto out;
 457
 458         iu = kzalloc(sizeof(*iu), gfp);
 459         if (!iu)
 460                 goto free;
 461
 462         usb_fill_bulk_urb(urb, udev, devinfo->status_pipe, iu, sizeof(*iu),
 463                           uas_stat_cmplt, cmnd->device->host);
 464         if (devinfo->use_streams)
 465                 urb->stream_id = cmdinfo->uas_tag;
 466         urb->transfer_flags |= URB_FREE_BUFFER;
 467  out:
 468         return urb;
 469  free:
 470         usb_free_urb(urb);
 471         return NULL;
 472 }
 473
 474 static struct urb *uas_alloc_cmd_urb(struct uas_dev_info *devinfo, gfp_t gfp,
 475                                         struct scsi_cmnd *cmnd)
 476 {
 477         struct usb_device *udev = devinfo->udev;
 478         struct scsi_device *sdev = cmnd->device;
 479         struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
 480         struct urb *urb = usb_alloc_urb(0, gfp);
 481         struct command_iu *iu;
 482         int len;
 483
 484         if (!urb)
 485                 goto out;
 486
 487         len = cmnd->cmd_len - 16;
 488         if (len < 0)
 489                 len = 0;
 490         len = ALIGN(len, 4);
 491         iu = kzalloc(sizeof(*iu) + len, gfp);
 492         if (!iu)
 493                 goto free;
 494
 495         iu->iu_id = IU_ID_COMMAND;
 496         iu->tag = cpu_to_be16(cmdinfo->uas_tag);
 497         iu->prio_attr = UAS_SIMPLE_TAG;
 498         iu->len = len;
 499         int_to_scsilun(sdev->lun, &iu->lun);
 500         memcpy(iu->cdb, cmnd->cmnd, cmnd->cmd_len);
 501
 502         usb_fill_bulk_urb(urb, udev, devinfo->cmd_pipe, iu, sizeof(*iu) + len,
 503                                                         uas_cmd_cmplt, NULL);
 504         urb->transfer_flags |= URB_FREE_BUFFER;
 505  out:
 506         return urb;
 507  free:
 508         usb_free_urb(urb);
 509         return NULL;
 510 }
 511
 512 /*
 513  * Why should I request the Status IU before sending the Command IU?  Spec
 514  * says to, but also says the device may receive them in any order.  Seems
 515  * daft to me.
 516  */
 517
 518 static struct urb *uas_submit_sense_urb(struct scsi_cmnd *cmnd, gfp_t gfp)
 519 {
 520         struct uas_dev_info *devinfo = cmnd->device->hostdata;
 521         struct urb *urb;
 522         int err;
 523
 524         urb = uas_alloc_sense_urb(devinfo, gfp, cmnd);
 525         if (!urb)
 526                 return NULL;
 527         usb_anchor_urb(urb, &devinfo->sense_urbs);
 528         err = usb_submit_urb(urb, gfp);
 529         if (err) {
 530                 usb_unanchor_urb(urb);
 531                 uas_log_cmd_state(cmnd, "sense submit err", err);
 532                 usb_free_urb(urb);
 533                 return NULL;
 534         }
 535         return urb;
 536 }
 537
 538 static int uas_submit_urbs(struct scsi_cmnd *cmnd,
 539                            struct uas_dev_info *devinfo)
 540 {
 541         struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
 542         struct urb *urb;
 543         int err;
 544
 545         lockdep_assert_held(&devinfo->lock);
 546         if (cmdinfo->state & SUBMIT_STATUS_URB) {
 547                 urb = uas_submit_sense_urb(cmnd, GFP_ATOMIC);
 548                 if (!urb)
 549                         return SCSI_MLQUEUE_DEVICE_BUSY;
 550                 cmdinfo->state &= ~SUBMIT_STATUS_URB;
 551         }
 552
 553         if (cmdinfo->state & ALLOC_DATA_IN_URB) {
 554                 cmdinfo->data_in_urb = uas_alloc_data_urb(devinfo, GFP_ATOMIC,
 555                                                         cmnd, DMA_FROM_DEVICE);
 556                 if (!cmdinfo->data_in_urb)
 557                         return SCSI_MLQUEUE_DEVICE_BUSY;
 558                 cmdinfo->state &= ~ALLOC_DATA_IN_URB;
 559         }
 560
 561         if (cmdinfo->state & SUBMIT_DATA_IN_URB) {
 562                 usb_anchor_urb(cmdinfo->data_in_urb, &devinfo->data_urbs);
 563                 err = usb_submit_urb(cmdinfo->data_in_urb, GFP_ATOMIC);
 564                 if (err) {
 565                         usb_unanchor_urb(cmdinfo->data_in_urb);
 566                         uas_log_cmd_state(cmnd, "data in submit err", err);
 567                         return SCSI_MLQUEUE_DEVICE_BUSY;
 568                 }
 569                 cmdinfo->state &= ~SUBMIT_DATA_IN_URB;
 570                 cmdinfo->state |= DATA_IN_URB_INFLIGHT;
 571         }
 572
 573         if (cmdinfo->state & ALLOC_DATA_OUT_URB) {
 574                 cmdinfo->data_out_urb = uas_alloc_data_urb(devinfo, GFP_ATOMIC,
 575                                                         cmnd, DMA_TO_DEVICE);
 576                 if (!cmdinfo->data_out_urb)
 577                         return SCSI_MLQUEUE_DEVICE_BUSY;
 578                 cmdinfo->state &= ~ALLOC_DATA_OUT_URB;
 579         }
 580
 581         if (cmdinfo->state & SUBMIT_DATA_OUT_URB) {
 582                 usb_anchor_urb(cmdinfo->data_out_urb, &devinfo->data_urbs);
 583                 err = usb_submit_urb(cmdinfo->data_out_urb, GFP_ATOMIC);
 584                 if (err) {
 585                         usb_unanchor_urb(cmdinfo->data_out_urb);
 586                         uas_log_cmd_state(cmnd, "data out submit err", err);
 587                         return SCSI_MLQUEUE_DEVICE_BUSY;
 588                 }
 589                 cmdinfo->state &= ~SUBMIT_DATA_OUT_URB;
 590                 cmdinfo->state |= DATA_OUT_URB_INFLIGHT;
 591         }
 592
 593         if (cmdinfo->state & ALLOC_CMD_URB) {
 594                 cmdinfo->cmd_urb = uas_alloc_cmd_urb(devinfo, GFP_ATOMIC, cmnd);
 595                 if (!cmdinfo->cmd_urb)
 596                         return SCSI_MLQUEUE_DEVICE_BUSY;
 597                 cmdinfo->state &= ~ALLOC_CMD_URB;
 598         }
 599
 600         if (cmdinfo->state & SUBMIT_CMD_URB) {
 601                 usb_anchor_urb(cmdinfo->cmd_urb, &devinfo->cmd_urbs);
 602                 err = usb_submit_urb(cmdinfo->cmd_urb, GFP_ATOMIC);
 603                 if (err) {
 604                         usb_unanchor_urb(cmdinfo->cmd_urb);
 605                         uas_log_cmd_state(cmnd, "cmd submit err", err);
 606                         return SCSI_MLQUEUE_DEVICE_BUSY;
 607                 }
 608                 cmdinfo->cmd_urb = NULL;
 609                 cmdinfo->state &= ~SUBMIT_CMD_URB;
 610                 cmdinfo->state |= COMMAND_INFLIGHT;
 611         }
 612
 613         return 0;
 614 }
 615
 616 static int uas_queuecommand_lck(struct scsi_cmnd *cmnd,
 617                                         void (*done)(struct scsi_cmnd *))
 618 {
 619         struct scsi_device *sdev = cmnd->device;
 620         struct uas_dev_info *devinfo = sdev->hostdata;
 621         struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
 622         unsigned long flags;
 623         int idx, err;
 624
 625         BUILD_BUG_ON(sizeof(struct uas_cmd_info) > sizeof(struct scsi_pointer));
 626
 627         /* Re-check scsi_block_requests now that we've the host-lock */
 628         if (cmnd->device->host->host_self_blocked)
 629                 return SCSI_MLQUEUE_DEVICE_BUSY;
 630
 631         if ((devinfo->flags & US_FL_NO_ATA_1X) &&
 632                         (cmnd->cmnd[0] == ATA_12 || cmnd->cmnd[0] == ATA_16)) {
 633                 memcpy(cmnd->sense_buffer, usb_stor_sense_invalidCDB,
 634                        sizeof(usb_stor_sense_invalidCDB));
 635                 cmnd->result = SAM_STAT_CHECK_CONDITION;
 636                 cmnd->scsi_done(cmnd);
 637                 return 0;
 638         }
 639
 640         spin_lock_irqsave(&devinfo->lock, flags);
 641
 642         if (devinfo->resetting) {
 643                 cmnd->result = DID_ERROR << 16;
 644                 cmnd->scsi_done(cmnd);
 645                 spin_unlock_irqrestore(&devinfo->lock, flags);
 646                 return 0;
 647         }
 648
 649         /* Find a free uas-tag */
 650         for (idx = 0; idx < devinfo->qdepth; idx++) {
 651                 if (!devinfo->cmnd[idx])
 652                         break;
 653         }
 654         if (idx == devinfo->qdepth) {
 655                 spin_unlock_irqrestore(&devinfo->lock, flags);
 656                 return SCSI_MLQUEUE_DEVICE_BUSY;
 657         }
 658
 659         cmnd->scsi_done = done;
 660
 661         memset(cmdinfo, 0, sizeof(*cmdinfo));
 662         cmdinfo->uas_tag = idx + 1; /* uas-tag == usb-stream-id, so 1 based */
 663         cmdinfo->state = SUBMIT_STATUS_URB | ALLOC_CMD_URB | SUBMIT_CMD_URB;
 664
 665         switch (cmnd->sc_data_direction) {
 666         case DMA_FROM_DEVICE:
 667                 cmdinfo->state |= ALLOC_DATA_IN_URB | SUBMIT_DATA_IN_URB;
 668                 break;
 669         case DMA_BIDIRECTIONAL:
 670                 cmdinfo->state |= ALLOC_DATA_IN_URB | SUBMIT_DATA_IN_URB;
 671         case DMA_TO_DEVICE:
 672                 cmdinfo->state |= ALLOC_DATA_OUT_URB | SUBMIT_DATA_OUT_URB;
 673         case DMA_NONE:
 674                 break;
 675         }
 676
 677         if (!devinfo->use_streams)
 678                 cmdinfo->state &= ~(SUBMIT_DATA_IN_URB | SUBMIT_DATA_OUT_URB);
 679
 680         err = uas_submit_urbs(cmnd, devinfo);
 681         if (err) {
 682                 /* If we did nothing, give up now */
 683                 if (cmdinfo->state & SUBMIT_STATUS_URB) {
 684                         spin_unlock_irqrestore(&devinfo->lock, flags);
 685                         return SCSI_MLQUEUE_DEVICE_BUSY;
 686                 }
 687                 uas_add_work(cmdinfo);
 688         }
 689
 690         devinfo->cmnd[idx] = cmnd;
 691         spin_unlock_irqrestore(&devinfo->lock, flags);
 692         return 0;
 693 }
 694
 695 static DEF_SCSI_QCMD(uas_queuecommand)
 696
 697 /*
 698  * For now we do not support actually sending an abort to the device, so
 699  * this eh always fails. Still we must define it to make sure that we've
 700  * dropped all references to the cmnd in question once this function exits.
 701  */
 702 static int uas_eh_abort_handler(struct scsi_cmnd *cmnd)
 703 {
 704         struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
 705         struct uas_dev_info *devinfo = (void *)cmnd->device->hostdata;
 706         struct urb *data_in_urb = NULL;
 707         struct urb *data_out_urb = NULL;
 708         unsigned long flags;
 709
 710         spin_lock_irqsave(&devinfo->lock, flags);
 711
 712         uas_log_cmd_state(cmnd, __func__, 0);
 713
 714         /* Ensure that try_complete does not call scsi_done */
 715         cmdinfo->state |= COMMAND_ABORTED;
 716
 717         /* Drop all refs to this cmnd, kill data urbs to break their ref */
 718         devinfo->cmnd[cmdinfo->uas_tag - 1] = NULL;
 719         if (cmdinfo->state & DATA_IN_URB_INFLIGHT)
 720                 data_in_urb = usb_get_urb(cmdinfo->data_in_urb);
 721         if (cmdinfo->state & DATA_OUT_URB_INFLIGHT)
 722                 data_out_urb = usb_get_urb(cmdinfo->data_out_urb);
 723
 724         uas_free_unsubmitted_urbs(cmnd);
 725
 726         spin_unlock_irqrestore(&devinfo->lock, flags);
 727
 728         if (data_in_urb) {
 729                 usb_kill_urb(data_in_urb);
 730                 usb_put_urb(data_in_urb);
 731         }
 732         if (data_out_urb) {
 733                 usb_kill_urb(data_out_urb);
 734                 usb_put_urb(data_out_urb);
 735         }
 736
 737         return FAILED;
 738 }
 739
 740 static int uas_eh_device_reset_handler(struct scsi_cmnd *cmnd)
 741 {
 742         struct scsi_device *sdev = cmnd->device;
 743         struct uas_dev_info *devinfo = sdev->hostdata;
 744         struct usb_device *udev = devinfo->udev;
 745         unsigned long flags;
 746         int err;
 747
 748         err = usb_lock_device_for_reset(udev, devinfo->intf);
 749         if (err) {
 750                 shost_printk(KERN_ERR, sdev->host,
 751                              "%s FAILED to get lock err %d\n", __func__, err);
 752                 return FAILED;
 753         }
 754
 755         shost_printk(KERN_INFO, sdev->host, "%s start\n", __func__);
 756
 757         spin_lock_irqsave(&devinfo->lock, flags);
 758         devinfo->resetting = 1;
 759         spin_unlock_irqrestore(&devinfo->lock, flags);
 760
 761         usb_kill_anchored_urbs(&devinfo->cmd_urbs);
 762         usb_kill_anchored_urbs(&devinfo->sense_urbs);
 763         usb_kill_anchored_urbs(&devinfo->data_urbs);
 764         uas_zap_pending(devinfo, DID_RESET);
 765
 766         err = usb_reset_device(udev);
 767
 768         spin_lock_irqsave(&devinfo->lock, flags);
 769         devinfo->resetting = 0;
 770         spin_unlock_irqrestore(&devinfo->lock, flags);
 771
 772         usb_unlock_device(udev);
 773
 774         if (err) {
 775                 shost_printk(KERN_INFO, sdev->host, "%s FAILED err %d\n",
 776                              __func__, err);
 777                 return FAILED;
 778         }
 779
 780         shost_printk(KERN_INFO, sdev->host, "%s success\n", __func__);
 781         return SUCCESS;
 782 }
 783
 784 static int uas_target_alloc(struct scsi_target *starget)
 785 {
 786         struct uas_dev_info *devinfo = (struct uas_dev_info *)
 787                         dev_to_shost(starget->dev.parent)->hostdata;
 788
 789         if (devinfo->flags & US_FL_NO_REPORT_LUNS)
 790                 starget->no_report_luns = 1;
 791
 792         return 0;
 793 }
 794
 795 static int uas_slave_alloc(struct scsi_device *sdev)
 796 {
 797         struct uas_dev_info *devinfo =
 798                 (struct uas_dev_info *)sdev->host->hostdata;
 799
 800         sdev->hostdata = devinfo;
 801
 802         /*
 803          * USB has unusual DMA-alignment requirements: Although the
 804          * starting address of each scatter-gather element doesn't matter,
 805          * the length of each element except the last must be divisible
 806          * by the Bulk maxpacket value.  There's currently no way to
 807          * express this by block-layer constraints, so we'll cop out
 808          * and simply require addresses to be aligned at 512-byte
 809          * boundaries.  This is okay since most block I/O involves
 810          * hardware sectors that are multiples of 512 bytes in length,
 811          * and since host controllers up through USB 2.0 have maxpacket
 812          * values no larger than 512.
 813          *
 814          * But it doesn't suffice for Wireless USB, where Bulk maxpacket
 815          * values can be as large as 2048.  To make that work properly
 816          * will require changes to the block layer.
 817          */
 818         blk_queue_update_dma_alignment(sdev->request_queue, (512 - 1));
 819
 820         if (devinfo->flags & US_FL_MAX_SECTORS_64)
 821                 blk_queue_max_hw_sectors(sdev->request_queue, 64);
 822         else if (devinfo->flags & US_FL_MAX_SECTORS_240)
 823                 blk_queue_max_hw_sectors(sdev->request_queue, 240);
 824
 825         return 0;
 826 }
 827
 828 static int uas_slave_configure(struct scsi_device *sdev)
 829 {
 830         struct uas_dev_info *devinfo = sdev->hostdata;
 831
 832         if (devinfo->flags & US_FL_NO_REPORT_OPCODES)
 833                 sdev->no_report_opcodes = 1;
 834
 835         /* A few buggy USB-ATA bridges don't understand FUA */
 836         if (devinfo->flags & US_FL_BROKEN_FUA)
 837                 sdev->broken_fua = 1;
 838
 839         scsi_change_queue_depth(sdev, devinfo->qdepth - 2);
 840         return 0;
 841 }
 842
 843 static struct scsi_host_template uas_host_template = {
 844         .module = THIS_MODULE,
 845         .name = "uas",
 846         .queuecommand = uas_queuecommand,
 847         .target_alloc = uas_target_alloc,
 848         .slave_alloc = uas_slave_alloc,
 849         .slave_configure = uas_slave_configure,
 850         .eh_abort_handler = uas_eh_abort_handler,
 851         .eh_device_reset_handler = uas_eh_device_reset_handler,
 852         .this_id = -1,
 853         .sg_tablesize = SG_NONE,
 854         .skip_settle_delay = 1,
 855 };
 856
 857 #define UNUSUAL_DEV(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax, \
 858                     vendorName, productName, useProtocol, useTransport, \
 859                     initFunction, flags) \
 860 { USB_DEVICE_VER(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax), \
 861         .driver_info = (flags) }
 862
 863 static struct usb_device_id uas_usb_ids[] = {
 864 #       include "unusual_uas.h"
 865         { USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, USB_SC_SCSI, USB_PR_BULK) },
 866         { USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, USB_SC_SCSI, USB_PR_UAS) },
 867         { }
 868 };
 869 MODULE_DEVICE_TABLE(usb, uas_usb_ids);
 870
 871 #undef UNUSUAL_DEV
 872
 873 static int uas_switch_interface(struct usb_device *udev,
 874                                 struct usb_interface *intf)
 875 {
 876         struct usb_host_interface *alt;
 877
 878         alt = uas_find_uas_alt_setting(intf);
 879         if (!alt)
 880                 return -ENODEV;
 881
 882         return usb_set_interface(udev, alt->desc.bInterfaceNumber,
 883                         alt->desc.bAlternateSetting);
 884 }
 885
 886 static int uas_configure_endpoints(struct uas_dev_info *devinfo)
 887 {
 888         struct usb_host_endpoint *eps[4] = { };
 889         struct usb_device *udev = devinfo->udev;
 890         int r;
 891
 892         r = uas_find_endpoints(devinfo->intf->cur_altsetting, eps);
 893         if (r)
 894                 return r;
 895
 896         devinfo->cmd_pipe = usb_sndbulkpipe(udev,
 897                                             usb_endpoint_num(&eps[0]->desc));
 898         devinfo->status_pipe = usb_rcvbulkpipe(udev,
 899                                             usb_endpoint_num(&eps[1]->desc));
 900         devinfo->data_in_pipe = usb_rcvbulkpipe(udev,
 901                                             usb_endpoint_num(&eps[2]->desc));
 902         devinfo->data_out_pipe = usb_sndbulkpipe(udev,
 903                                             usb_endpoint_num(&eps[3]->desc));
 904
 905         if (udev->speed < USB_SPEED_SUPER) {
 906                 devinfo->qdepth = 32;
 907                 devinfo->use_streams = 0;
 908         } else {
 909                 devinfo->qdepth = usb_alloc_streams(devinfo->intf, eps + 1,
 910                                                     3, MAX_CMNDS, GFP_NOIO);
 911                 if (devinfo->qdepth < 0)
 912                         return devinfo->qdepth;
 913                 devinfo->use_streams = 1;
 914         }
 915
 916         return 0;
 917 }
 918
 919 static void uas_free_streams(struct uas_dev_info *devinfo)
 920 {
 921         struct usb_device *udev = devinfo->udev;
 922         struct usb_host_endpoint *eps[3];
 923
 924         eps[0] = usb_pipe_endpoint(udev, devinfo->status_pipe);
 925         eps[1] = usb_pipe_endpoint(udev, devinfo->data_in_pipe);
 926         eps[2] = usb_pipe_endpoint(udev, devinfo->data_out_pipe);
 927         usb_free_streams(devinfo->intf, eps, 3, GFP_NOIO);
 928 }
 929
 930 static int uas_probe(struct usb_interface *intf, const struct usb_device_id *id)
 931 {
 932         int result = -ENOMEM;
 933         struct Scsi_Host *shost = NULL;
 934         struct uas_dev_info *devinfo;
 935         struct usb_device *udev = interface_to_usbdev(intf);
 936         unsigned long dev_flags;
 937
 938         if (!uas_use_uas_driver(intf, id, &dev_flags))
 939                 return -ENODEV;
 940
 941         if (uas_switch_interface(udev, intf))
 942                 return -ENODEV;
 943
 944         shost = scsi_host_alloc(&uas_host_template,
 945                                 sizeof(struct uas_dev_info));
 946         if (!shost)
 947                 goto set_alt0;
 948
 949         shost->max_cmd_len = 16 + 252;
 950         shost->max_id = 1;
 951         shost->max_lun = 256;
 952         shost->max_channel = 0;
 953         shost->sg_tablesize = udev->bus->sg_tablesize;
 954
 955         devinfo = (struct uas_dev_info *)shost->hostdata;
 956         devinfo->intf = intf;
 957         devinfo->udev = udev;
 958         devinfo->resetting = 0;
 959         devinfo->shutdown = 0;
 960         devinfo->flags = dev_flags;
 961         init_usb_anchor(&devinfo->cmd_urbs);
 962         init_usb_anchor(&devinfo->sense_urbs);
 963         init_usb_anchor(&devinfo->data_urbs);
 964         spin_lock_init(&devinfo->lock);
 965         INIT_WORK(&devinfo->work, uas_do_work);
 966
 967         result = uas_configure_endpoints(devinfo);
 968         if (result)
 969                 goto set_alt0;
 970
 971         /*
 972          * 1 tag is reserved for untagged commands +
 973          * 1 tag to avoid off by one errors in some bridge firmwares
 974          */
 975         shost->can_queue = devinfo->qdepth - 2;
 976
 977         usb_set_intfdata(intf, shost);
 978         result = scsi_add_host(shost, &intf->dev);
 979         if (result)
 980                 goto free_streams;
 981
 982         scsi_scan_host(shost);
 983         return result;
 984
 985 free_streams:
 986         uas_free_streams(devinfo);
 987         usb_set_intfdata(intf, NULL);
 988 set_alt0:
 989         usb_set_interface(udev, intf->altsetting[0].desc.bInterfaceNumber, 0);
 990         if (shost)
 991                 scsi_host_put(shost);
 992         return result;
 993 }
 994
 995 static int uas_cmnd_list_empty(struct uas_dev_info *devinfo)
 996 {
 997         unsigned long flags;
 998         int i, r = 1;
 999
1000         spin_lock_irqsave(&devinfo->lock, flags);
1001
1002         for (i = 0; i < devinfo->qdepth; i++) {
1003                 if (devinfo->cmnd[i]) {
1004                         r = 0; /* Not empty */
1005                         break;
1006                 }
1007         }
1008
1009         spin_unlock_irqrestore(&devinfo->lock, flags);
1010
1011         return r;
1012 }
1013
1014 /*
1015  * Wait for any pending cmnds to complete, on usb-2 sense_urbs may temporarily
1016  * get empty while there still is more work to do due to sense-urbs completing
1017  * with a READ/WRITE_READY iu code, so keep waiting until the list gets empty.
1018  */
1019 static int uas_wait_for_pending_cmnds(struct uas_dev_info *devinfo)
1020 {
1021         unsigned long start_time;
1022         int r;
1023
1024         start_time = jiffies;
1025         do {
1026                 flush_work(&devinfo->work);
1027
1028                 r = usb_wait_anchor_empty_timeout(&devinfo->sense_urbs, 5000);
1029                 if (r == 0)
1030                         return -ETIME;
1031
1032                 r = usb_wait_anchor_empty_timeout(&devinfo->data_urbs, 500);
1033                 if (r == 0)
1034                         return -ETIME;
1035
1036                 if (time_after(jiffies, start_time + 5 * HZ))
1037                         return -ETIME;
1038         } while (!uas_cmnd_list_empty(devinfo));
1039
1040         return 0;
1041 }
1042
1043 static int uas_pre_reset(struct usb_interface *intf)
1044 {
1045         struct Scsi_Host *shost = usb_get_intfdata(intf);
1046         struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
1047         unsigned long flags;
1048
1049         if (devinfo->shutdown)
1050                 return 0;
1051
1052         /* Block new requests */
1053         spin_lock_irqsave(shost->host_lock, flags);
1054         scsi_block_requests(shost);
1055         spin_unlock_irqrestore(shost->host_lock, flags);
1056
1057         if (uas_wait_for_pending_cmnds(devinfo) != 0) {
1058                 shost_printk(KERN_ERR, shost, "%s: timed out\n", __func__);
1059                 scsi_unblock_requests(shost);
1060                 return 1;
1061         }
1062
1063         uas_free_streams(devinfo);
1064
1065         return 0;
1066 }
1067
1068 static int uas_post_reset(struct usb_interface *intf)
1069 {
1070         struct Scsi_Host *shost = usb_get_intfdata(intf);
1071         struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
1072         unsigned long flags;
1073         int err;
1074
1075         if (devinfo->shutdown)
1076                 return 0;
1077
1078         err = uas_configure_endpoints(devinfo);
1079         if (err) {
1080                 shost_printk(KERN_ERR, shost,
1081                              "%s: alloc streams error %d after reset",
1082                              __func__, err);
1083                 return 1;
1084         }
1085
1086         spin_lock_irqsave(shost->host_lock, flags);
1087         scsi_report_bus_reset(shost, 0);
1088         spin_unlock_irqrestore(shost->host_lock, flags);
1089
1090         scsi_unblock_requests(shost);
1091
1092         return 0;
1093 }
1094
1095 static int uas_suspend(struct usb_interface *intf, pm_message_t message)
1096 {
1097         struct Scsi_Host *shost = usb_get_intfdata(intf);
1098         struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
1099
1100         if (uas_wait_for_pending_cmnds(devinfo) != 0) {
1101                 shost_printk(KERN_ERR, shost, "%s: timed out\n", __func__);
1102                 return -ETIME;
1103         }
1104
1105         return 0;
1106 }
1107
1108 static int uas_resume(struct usb_interface *intf)
1109 {
1110         return 0;
1111 }
1112
1113 static int uas_reset_resume(struct usb_interface *intf)
1114 {
1115         struct Scsi_Host *shost = usb_get_intfdata(intf);
1116         struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
1117         unsigned long flags;
1118         int err;
1119
1120         err = uas_configure_endpoints(devinfo);
1121         if (err) {
1122                 shost_printk(KERN_ERR, shost,
1123                              "%s: alloc streams error %d after reset",
1124                              __func__, err);
1125                 return -EIO;
1126         }
1127
1128         spin_lock_irqsave(shost->host_lock, flags);
1129         scsi_report_bus_reset(shost, 0);
1130         spin_unlock_irqrestore(shost->host_lock, flags);
1131
1132         return 0;
1133 }
1134
1135 static void uas_disconnect(struct usb_interface *intf)
1136 {
1137         struct Scsi_Host *shost = usb_get_intfdata(intf);
1138         struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
1139         unsigned long flags;
1140
1141         spin_lock_irqsave(&devinfo->lock, flags);
1142         devinfo->resetting = 1;
1143         spin_unlock_irqrestore(&devinfo->lock, flags);
1144
1145         cancel_work_sync(&devinfo->work);
1146         usb_kill_anchored_urbs(&devinfo->cmd_urbs);
1147         usb_kill_anchored_urbs(&devinfo->sense_urbs);
1148         usb_kill_anchored_urbs(&devinfo->data_urbs);
1149         uas_zap_pending(devinfo, DID_NO_CONNECT);
1150
1151         scsi_remove_host(shost);
1152         uas_free_streams(devinfo);
1153         scsi_host_put(shost);
1154 }
1155
1156 /*
1157  * Put the device back in usb-storage mode on shutdown, as some BIOS-es
1158  * hang on reboot when the device is still in uas mode. Note the reset is
1159  * necessary as some devices won't revert to usb-storage mode without it.
1160  */
1161 static void uas_shutdown(struct device *dev)
1162 {
1163         struct usb_interface *intf = to_usb_interface(dev);
1164         struct usb_device *udev = interface_to_usbdev(intf);
1165         struct Scsi_Host *shost = usb_get_intfdata(intf);
1166         struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
1167
1168         if (system_state != SYSTEM_RESTART)
1169                 return;
1170
1171         devinfo->shutdown = 1;
1172         uas_free_streams(devinfo);
1173         usb_set_interface(udev, intf->altsetting[0].desc.bInterfaceNumber, 0);
1174         usb_reset_device(udev);
1175 }
1176
1177 static struct usb_driver uas_driver = {
1178         .name = "uas",
1179         .probe = uas_probe,
1180         .disconnect = uas_disconnect,
1181         .pre_reset = uas_pre_reset,
1182         .post_reset = uas_post_reset,
1183         .suspend = uas_suspend,
1184         .resume = uas_resume,
1185         .reset_resume = uas_reset_resume,
1186         .drvwrap.driver.shutdown = uas_shutdown,
1187         .id_table = uas_usb_ids,
1188 };
1189
1190 module_usb_driver(uas_driver);
1191
1192 MODULE_LICENSE("GPL");
1193 MODULE_AUTHOR(
1194         "Hans de Goede <hdegoede@redhat.com>, Matthew Wilcox and Sarah Sharp");