1/* Driver for USB Mass Storage compliant devices
   2 *
   3 * Current development and maintenance by:
   4 *   (c) 1999-2002 Matthew Dharm (mdharm-usb@one-eyed-alien.net)
   5 *
   6 * Developed with the assistance of:
   7 *   (c) 2000 David L. Brown, Jr. (usb-storage@davidb.org)
   8 *   (c) 2000 Stephen J. Gowdy (SGowdy@lbl.gov)
   9 *   (c) 2002 Alan Stern <stern@rowland.org>
  10 *
  11 * Initial work by:
  12 *   (c) 1999 Michael Gee (michael@linuxspecific.com)
  13 *
  14 * This driver is based on the 'USB Mass Storage Class' document. This
  15 * describes in detail the protocol used to communicate with such
  16 * devices.  Clearly, the designers had SCSI and ATAPI commands in
  17 * mind when they created this document.  The commands are all very
  18 * similar to commands in the SCSI-II and ATAPI specifications.
  19 *
  20 * It is important to note that in a number of cases this class
  21 * exhibits class-specific exemptions from the USB specification.
  22 * Notably the usage of NAK, STALL and ACK differs from the norm, in
  23 * that they are used to communicate wait, failed and OK on commands.
  24 *
  25 * Also, for certain devices, the interrupt endpoint is used to convey
  26 * status of a command.
  27 *
  28 * Please see http://www.one-eyed-alien.net/~mdharm/linux-usb for more
  29 * information about this driver.
  30 *
  31 * This program is free software; you can redistribute it and/or modify it
  32 * under the terms of the GNU General Public License as published by the
  33 * Free Software Foundation; either version 2, or (at your option) any
  34 * later version.
  35 *
  36 * This program is distributed in the hope that it will be useful, but
  37 * WITHOUT ANY WARRANTY; without even the implied warranty of
  38 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  39 * General Public License for more details.
  40 *
  41 * You should have received a copy of the GNU General Public License along
  42 * with this program; if not, write to the Free Software Foundation, Inc.,
  43 * 675 Mass Ave, Cambridge, MA 02139, USA.
  44 */
  45
  46#include <linux/sched.h>
  47#include <linux/gfp.h>
  48#include <linux/errno.h>
 
  49
  50#include <linux/usb/quirks.h>
  51
  52#include <scsi/scsi.h>
  53#include <scsi/scsi_eh.h>
  54#include <scsi/scsi_device.h>
  55
  56#include "usb.h"
  57#include "transport.h"
  58#include "protocol.h"
  59#include "scsiglue.h"
  60#include "debug.h"
  61
  62#include <linux/blkdev.h>
  63#include "../../scsi/sd.h"
  64
  65
  66/***********************************************************************
  67 * Data transfer routines
  68 ***********************************************************************/
  69
  70/*
  71 * This is subtle, so pay attention:
  72 * ---------------------------------
  73 * We're very concerned about races with a command abort.  Hanging this code
  74 * is a sure fire way to hang the kernel.  (Note that this discussion applies
  75 * only to transactions resulting from a scsi queued-command, since only
  76 * these transactions are subject to a scsi abort.  Other transactions, such
  77 * as those occurring during device-specific initialization, must be handled
  78 * by a separate code path.)
  79 *
  80 * The abort function (usb_storage_command_abort() in scsiglue.c) first
  81 * sets the machine state and the ABORTING bit in us->dflags to prevent
  82 * new URBs from being submitted.  It then calls usb_stor_stop_transport()
  83 * below, which atomically tests-and-clears the URB_ACTIVE bit in us->dflags
  84 * to see if the current_urb needs to be stopped.  Likewise, the SG_ACTIVE
  85 * bit is tested to see if the current_sg scatter-gather request needs to be
  86 * stopped.  The timeout callback routine does much the same thing.
  87 *
  88 * When a disconnect occurs, the DISCONNECTING bit in us->dflags is set to
  89 * prevent new URBs from being submitted, and usb_stor_stop_transport() is
  90 * called to stop any ongoing requests.
  91 *
  92 * The submit function first verifies that the submitting is allowed
  93 * (neither ABORTING nor DISCONNECTING bits are set) and that the submit
  94 * completes without errors, and only then sets the URB_ACTIVE bit.  This
  95 * prevents the stop_transport() function from trying to cancel the URB
  96 * while the submit call is underway.  Next, the submit function must test
  97 * the flags to see if an abort or disconnect occurred during the submission
  98 * or before the URB_ACTIVE bit was set.  If so, it's essential to cancel
  99 * the URB if it hasn't been cancelled already (i.e., if the URB_ACTIVE bit
 100 * is still set).  Either way, the function must then wait for the URB to
 101 * finish.  Note that the URB can still be in progress even after a call to
 102 * usb_unlink_urb() returns.
 103 *
 104 * The idea is that (1) once the ABORTING or DISCONNECTING bit is set,
 105 * either the stop_transport() function or the submitting function
 106 * is guaranteed to call usb_unlink_urb() for an active URB,
 107 * and (2) test_and_clear_bit() prevents usb_unlink_urb() from being
 108 * called more than once or from being called during usb_submit_urb().
 109 */
 110
 111/* This is the completion handler which will wake us up when an URB
 112 * completes.
 113 */
 114static void usb_stor_blocking_completion(struct urb *urb)
 115{
 116	struct completion *urb_done_ptr = urb->context;
 117
 118	complete(urb_done_ptr);
 119}
 120
 121/* This is the common part of the URB message submission code
 122 *
 123 * All URBs from the usb-storage driver involved in handling a queued scsi
 124 * command _must_ pass through this function (or something like it) for the
 125 * abort mechanisms to work properly.
 126 */
 127static int usb_stor_msg_common(struct us_data *us, int timeout)
 128{
 129	struct completion urb_done;
 130	long timeleft;
 131	int status;
 132
 133	/* don't submit URBs during abort processing */
 134	if (test_bit(US_FLIDX_ABORTING, &us->dflags))
 135		return -EIO;
 136
 137	/* set up data structures for the wakeup system */
 138	init_completion(&urb_done);
 139
 140	/* fill the common fields in the URB */
 141	us->current_urb->context = &urb_done;
 142	us->current_urb->transfer_flags = 0;
 143
 144	/* we assume that if transfer_buffer isn't us->iobuf then it
 145	 * hasn't been mapped for DMA.  Yes, this is clunky, but it's
 146	 * easier than always having the caller tell us whether the
 147	 * transfer buffer has already been mapped. */
 148	if (us->current_urb->transfer_buffer == us->iobuf)
 149		us->current_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 150	us->current_urb->transfer_dma = us->iobuf_dma;
 151
 152	/* submit the URB */
 153	status = usb_submit_urb(us->current_urb, GFP_NOIO);
 154	if (status) {
 155		/* something went wrong */
 156		return status;
 157	}
 158
 159	/* since the URB has been submitted successfully, it's now okay
 160	 * to cancel it */
 161	set_bit(US_FLIDX_URB_ACTIVE, &us->dflags);
 162
 163	/* did an abort occur during the submission? */
 164	if (test_bit(US_FLIDX_ABORTING, &us->dflags)) {
 165
 166		/* cancel the URB, if it hasn't been cancelled already */
 167		if (test_and_clear_bit(US_FLIDX_URB_ACTIVE, &us->dflags)) {
 168			US_DEBUGP("-- cancelling URB\n");
 169			usb_unlink_urb(us->current_urb);
 170		}
 171	}
 172 
 173	/* wait for the completion of the URB */
 174	timeleft = wait_for_completion_interruptible_timeout(
 175			&urb_done, timeout ? : MAX_SCHEDULE_TIMEOUT);
 176 
 177	clear_bit(US_FLIDX_URB_ACTIVE, &us->dflags);
 178
 179	if (timeleft <= 0) {
 180		US_DEBUGP("%s -- cancelling URB\n",
 181			  timeleft == 0 ? "Timeout" : "Signal");
 182		usb_kill_urb(us->current_urb);
 183	}
 184
 185	/* return the URB status */
 186	return us->current_urb->status;
 187}
 188
 189/*
 190 * Transfer one control message, with timeouts, and allowing early
 191 * termination.  Return codes are usual -Exxx, *not* USB_STOR_XFER_xxx.
 192 */
 193int usb_stor_control_msg(struct us_data *us, unsigned int pipe,
 194		 u8 request, u8 requesttype, u16 value, u16 index, 
 195		 void *data, u16 size, int timeout)
 196{
 197	int status;
 198
 199	US_DEBUGP("%s: rq=%02x rqtype=%02x value=%04x index=%02x len=%u\n",
 200			__func__, request, requesttype,
 201			value, index, size);
 202
 203	/* fill in the devrequest structure */
 204	us->cr->bRequestType = requesttype;
 205	us->cr->bRequest = request;
 206	us->cr->wValue = cpu_to_le16(value);
 207	us->cr->wIndex = cpu_to_le16(index);
 208	us->cr->wLength = cpu_to_le16(size);
 209
 210	/* fill and submit the URB */
 211	usb_fill_control_urb(us->current_urb, us->pusb_dev, pipe, 
 212			 (unsigned char*) us->cr, data, size, 
 213			 usb_stor_blocking_completion, NULL);
 214	status = usb_stor_msg_common(us, timeout);
 215
 216	/* return the actual length of the data transferred if no error */
 217	if (status == 0)
 218		status = us->current_urb->actual_length;
 219	return status;
 220}
 221EXPORT_SYMBOL_GPL(usb_stor_control_msg);
 222
 223/* This is a version of usb_clear_halt() that allows early termination and
 224 * doesn't read the status from the device -- this is because some devices
 225 * crash their internal firmware when the status is requested after a halt.
 226 *
 227 * A definitive list of these 'bad' devices is too difficult to maintain or
 228 * make complete enough to be useful.  This problem was first observed on the
 229 * Hagiwara FlashGate DUAL unit.  However, bus traces reveal that neither
 230 * MacOS nor Windows checks the status after clearing a halt.
 231 *
 232 * Since many vendors in this space limit their testing to interoperability
 233 * with these two OSes, specification violations like this one are common.
 234 */
 235int usb_stor_clear_halt(struct us_data *us, unsigned int pipe)
 236{
 237	int result;
 238	int endp = usb_pipeendpoint(pipe);
 239
 240	if (usb_pipein (pipe))
 241		endp |= USB_DIR_IN;
 242
 243	result = usb_stor_control_msg(us, us->send_ctrl_pipe,
 244		USB_REQ_CLEAR_FEATURE, USB_RECIP_ENDPOINT,
 245		USB_ENDPOINT_HALT, endp,
 246		NULL, 0, 3*HZ);
 247
 248	if (result >= 0)
 249		usb_reset_endpoint(us->pusb_dev, endp);
 250
 251	US_DEBUGP("%s: result = %d\n", __func__, result);
 252	return result;
 253}
 254EXPORT_SYMBOL_GPL(usb_stor_clear_halt);
 255
 256
 257/*
 258 * Interpret the results of a URB transfer
 259 *
 260 * This function prints appropriate debugging messages, clears halts on
 261 * non-control endpoints, and translates the status to the corresponding
 262 * USB_STOR_XFER_xxx return code.
 263 */
 264static int interpret_urb_result(struct us_data *us, unsigned int pipe,
 265		unsigned int length, int result, unsigned int partial)
 266{
 267	US_DEBUGP("Status code %d; transferred %u/%u\n",
 268			result, partial, length);
 269	switch (result) {
 270
 271	/* no error code; did we send all the data? */
 272	case 0:
 273		if (partial != length) {
 274			US_DEBUGP("-- short transfer\n");
 275			return USB_STOR_XFER_SHORT;
 276		}
 277
 278		US_DEBUGP("-- transfer complete\n");
 279		return USB_STOR_XFER_GOOD;
 280
 281	/* stalled */
 282	case -EPIPE:
 283		/* for control endpoints, (used by CB[I]) a stall indicates
 284		 * a failed command */
 285		if (usb_pipecontrol(pipe)) {
 286			US_DEBUGP("-- stall on control pipe\n");
 287			return USB_STOR_XFER_STALLED;
 288		}
 289
 290		/* for other sorts of endpoint, clear the stall */
 291		US_DEBUGP("clearing endpoint halt for pipe 0x%x\n", pipe);
 292		if (usb_stor_clear_halt(us, pipe) < 0)
 293			return USB_STOR_XFER_ERROR;
 294		return USB_STOR_XFER_STALLED;
 295
 296	/* babble - the device tried to send more than we wanted to read */
 297	case -EOVERFLOW:
 298		US_DEBUGP("-- babble\n");
 299		return USB_STOR_XFER_LONG;
 300
 301	/* the transfer was cancelled by abort, disconnect, or timeout */
 302	case -ECONNRESET:
 303		US_DEBUGP("-- transfer cancelled\n");
 304		return USB_STOR_XFER_ERROR;
 305
 306	/* short scatter-gather read transfer */
 307	case -EREMOTEIO:
 308		US_DEBUGP("-- short read transfer\n");
 309		return USB_STOR_XFER_SHORT;
 310
 311	/* abort or disconnect in progress */
 312	case -EIO:
 313		US_DEBUGP("-- abort or disconnect in progress\n");
 314		return USB_STOR_XFER_ERROR;
 315
 316	/* the catch-all error case */
 317	default:
 318		US_DEBUGP("-- unknown error\n");
 319		return USB_STOR_XFER_ERROR;
 320	}
 321}
 322
 323/*
 324 * Transfer one control message, without timeouts, but allowing early
 325 * termination.  Return codes are USB_STOR_XFER_xxx.
 326 */
 327int usb_stor_ctrl_transfer(struct us_data *us, unsigned int pipe,
 328		u8 request, u8 requesttype, u16 value, u16 index,
 329		void *data, u16 size)
 330{
 331	int result;
 332
 333	US_DEBUGP("%s: rq=%02x rqtype=%02x value=%04x index=%02x len=%u\n",
 334			__func__, request, requesttype,
 335			value, index, size);
 336
 337	/* fill in the devrequest structure */
 338	us->cr->bRequestType = requesttype;
 339	us->cr->bRequest = request;
 340	us->cr->wValue = cpu_to_le16(value);
 341	us->cr->wIndex = cpu_to_le16(index);
 342	us->cr->wLength = cpu_to_le16(size);
 343
 344	/* fill and submit the URB */
 345	usb_fill_control_urb(us->current_urb, us->pusb_dev, pipe, 
 346			 (unsigned char*) us->cr, data, size, 
 347			 usb_stor_blocking_completion, NULL);
 348	result = usb_stor_msg_common(us, 0);
 349
 350	return interpret_urb_result(us, pipe, size, result,
 351			us->current_urb->actual_length);
 352}
 353EXPORT_SYMBOL_GPL(usb_stor_ctrl_transfer);
 354
 355/*
 356 * Receive one interrupt buffer, without timeouts, but allowing early
 357 * termination.  Return codes are USB_STOR_XFER_xxx.
 358 *
 359 * This routine always uses us->recv_intr_pipe as the pipe and
 360 * us->ep_bInterval as the interrupt interval.
 361 */
 362static int usb_stor_intr_transfer(struct us_data *us, void *buf,
 363				  unsigned int length)
 364{
 365	int result;
 366	unsigned int pipe = us->recv_intr_pipe;
 367	unsigned int maxp;
 368
 369	US_DEBUGP("%s: xfer %u bytes\n", __func__, length);
 370
 371	/* calculate the max packet size */
 372	maxp = usb_maxpacket(us->pusb_dev, pipe, usb_pipeout(pipe));
 373	if (maxp > length)
 374		maxp = length;
 375
 376	/* fill and submit the URB */
 377	usb_fill_int_urb(us->current_urb, us->pusb_dev, pipe, buf,
 378			maxp, usb_stor_blocking_completion, NULL,
 379			us->ep_bInterval);
 380	result = usb_stor_msg_common(us, 0);
 381
 382	return interpret_urb_result(us, pipe, length, result,
 383			us->current_urb->actual_length);
 384}
 385
 386/*
 387 * Transfer one buffer via bulk pipe, without timeouts, but allowing early
 388 * termination.  Return codes are USB_STOR_XFER_xxx.  If the bulk pipe
 389 * stalls during the transfer, the halt is automatically cleared.
 390 */
 391int usb_stor_bulk_transfer_buf(struct us_data *us, unsigned int pipe,
 392	void *buf, unsigned int length, unsigned int *act_len)
 393{
 394	int result;
 395
 396	US_DEBUGP("%s: xfer %u bytes\n", __func__, length);
 397
 398	/* fill and submit the URB */
 399	usb_fill_bulk_urb(us->current_urb, us->pusb_dev, pipe, buf, length,
 400		      usb_stor_blocking_completion, NULL);
 401	result = usb_stor_msg_common(us, 0);
 402
 403	/* store the actual length of the data transferred */
 404	if (act_len)
 405		*act_len = us->current_urb->actual_length;
 406	return interpret_urb_result(us, pipe, length, result, 
 407			us->current_urb->actual_length);
 408}
 409EXPORT_SYMBOL_GPL(usb_stor_bulk_transfer_buf);
 410
 411/*
 412 * Transfer a scatter-gather list via bulk transfer
 413 *
 414 * This function does basically the same thing as usb_stor_bulk_transfer_buf()
 415 * above, but it uses the usbcore scatter-gather library.
 416 */
 417static int usb_stor_bulk_transfer_sglist(struct us_data *us, unsigned int pipe,
 418		struct scatterlist *sg, int num_sg, unsigned int length,
 419		unsigned int *act_len)
 420{
 421	int result;
 422
 423	/* don't submit s-g requests during abort processing */
 424	if (test_bit(US_FLIDX_ABORTING, &us->dflags))
 425		return USB_STOR_XFER_ERROR;
 426
 427	/* initialize the scatter-gather request block */
 428	US_DEBUGP("%s: xfer %u bytes, %d entries\n", __func__,
 429			length, num_sg);
 430	result = usb_sg_init(&us->current_sg, us->pusb_dev, pipe, 0,
 431			sg, num_sg, length, GFP_NOIO);
 432	if (result) {
 433		US_DEBUGP("usb_sg_init returned %d\n", result);
 434		return USB_STOR_XFER_ERROR;
 435	}
 436
 437	/* since the block has been initialized successfully, it's now
 438	 * okay to cancel it */
 439	set_bit(US_FLIDX_SG_ACTIVE, &us->dflags);
 440
 441	/* did an abort occur during the submission? */
 442	if (test_bit(US_FLIDX_ABORTING, &us->dflags)) {
 443
 444		/* cancel the request, if it hasn't been cancelled already */
 445		if (test_and_clear_bit(US_FLIDX_SG_ACTIVE, &us->dflags)) {
 446			US_DEBUGP("-- cancelling sg request\n");
 447			usb_sg_cancel(&us->current_sg);
 448		}
 449	}
 450
 451	/* wait for the completion of the transfer */
 452	usb_sg_wait(&us->current_sg);
 453	clear_bit(US_FLIDX_SG_ACTIVE, &us->dflags);
 454
 455	result = us->current_sg.status;
 456	if (act_len)
 457		*act_len = us->current_sg.bytes;
 458	return interpret_urb_result(us, pipe, length, result,
 459			us->current_sg.bytes);
 460}
 461
 462/*
 463 * Common used function. Transfer a complete command
 464 * via usb_stor_bulk_transfer_sglist() above. Set cmnd resid
 465 */
 466int usb_stor_bulk_srb(struct us_data* us, unsigned int pipe,
 467		      struct scsi_cmnd* srb)
 468{
 469	unsigned int partial;
 470	int result = usb_stor_bulk_transfer_sglist(us, pipe, scsi_sglist(srb),
 471				      scsi_sg_count(srb), scsi_bufflen(srb),
 472				      &partial);
 473
 474	scsi_set_resid(srb, scsi_bufflen(srb) - partial);
 475	return result;
 476}
 477EXPORT_SYMBOL_GPL(usb_stor_bulk_srb);
 478
 479/*
 480 * Transfer an entire SCSI command's worth of data payload over the bulk
 481 * pipe.
 482 *
 483 * Note that this uses usb_stor_bulk_transfer_buf() and
 484 * usb_stor_bulk_transfer_sglist() to achieve its goals --
 485 * this function simply determines whether we're going to use
 486 * scatter-gather or not, and acts appropriately.
 487 */
 488int usb_stor_bulk_transfer_sg(struct us_data* us, unsigned int pipe,
 489		void *buf, unsigned int length_left, int use_sg, int *residual)
 490{
 491	int result;
 492	unsigned int partial;
 493
 494	/* are we scatter-gathering? */
 495	if (use_sg) {
 496		/* use the usb core scatter-gather primitives */
 497		result = usb_stor_bulk_transfer_sglist(us, pipe,
 498				(struct scatterlist *) buf, use_sg,
 499				length_left, &partial);
 500		length_left -= partial;
 501	} else {
 502		/* no scatter-gather, just make the request */
 503		result = usb_stor_bulk_transfer_buf(us, pipe, buf, 
 504				length_left, &partial);
 505		length_left -= partial;
 506	}
 507
 508	/* store the residual and return the error code */
 509	if (residual)
 510		*residual = length_left;
 511	return result;
 512}
 513EXPORT_SYMBOL_GPL(usb_stor_bulk_transfer_sg);
 514
 515/***********************************************************************
 516 * Transport routines
 517 ***********************************************************************/
 518
 519/* There are so many devices that report the capacity incorrectly,
 520 * this routine was written to counteract some of the resulting
 521 * problems.
 522 */
 523static void last_sector_hacks(struct us_data *us, struct scsi_cmnd *srb)
 524{
 525	struct gendisk *disk;
 526	struct scsi_disk *sdkp;
 527	u32 sector;
 528
 529	/* To Report "Medium Error: Record Not Found */
 530	static unsigned char record_not_found[18] = {
 531		[0]	= 0x70,			/* current error */
 532		[2]	= MEDIUM_ERROR,		/* = 0x03 */
 533		[7]	= 0x0a,			/* additional length */
 534		[12]	= 0x14			/* Record Not Found */
 535	};
 536
 537	/* If last-sector problems can't occur, whether because the
 538	 * capacity was already decremented or because the device is
 539	 * known to report the correct capacity, then we don't need
 540	 * to do anything.
 541	 */
 542	if (!us->use_last_sector_hacks)
 543		return;
 544
 545	/* Was this command a READ(10) or a WRITE(10)? */
 546	if (srb->cmnd[0] != READ_10 && srb->cmnd[0] != WRITE_10)
 547		goto done;
 548
 549	/* Did this command access the last sector? */
 550	sector = (srb->cmnd[2] << 24) | (srb->cmnd[3] << 16) |
 551			(srb->cmnd[4] << 8) | (srb->cmnd[5]);
 552	disk = srb->request->rq_disk;
 553	if (!disk)
 554		goto done;
 555	sdkp = scsi_disk(disk);
 556	if (!sdkp)
 557		goto done;
 558	if (sector + 1 != sdkp->capacity)
 559		goto done;
 560
 561	if (srb->result == SAM_STAT_GOOD && scsi_get_resid(srb) == 0) {
 562
 563		/* The command succeeded.  We know this device doesn't
 564		 * have the last-sector bug, so stop checking it.
 565		 */
 566		us->use_last_sector_hacks = 0;
 567
 568	} else {
 569		/* The command failed.  Allow up to 3 retries in case this
 570		 * is some normal sort of failure.  After that, assume the
 571		 * capacity is wrong and we're trying to access the sector
 572		 * beyond the end.  Replace the result code and sense data
 573		 * with values that will cause the SCSI core to fail the
 574		 * command immediately, instead of going into an infinite
 575		 * (or even just a very long) retry loop.
 576		 */
 577		if (++us->last_sector_retries < 3)
 578			return;
 579		srb->result = SAM_STAT_CHECK_CONDITION;
 580		memcpy(srb->sense_buffer, record_not_found,
 581				sizeof(record_not_found));
 582	}
 583
 584 done:
 585	/* Don't reset the retry counter for TEST UNIT READY commands,
 586	 * because they get issued after device resets which might be
 587	 * caused by a failed last-sector access.
 588	 */
 589	if (srb->cmnd[0] != TEST_UNIT_READY)
 590		us->last_sector_retries = 0;
 591}
 592
 593/* Invoke the transport and basic error-handling/recovery methods
 594 *
 595 * This is used by the protocol layers to actually send the message to
 596 * the device and receive the response.
 597 */
 598void usb_stor_invoke_transport(struct scsi_cmnd *srb, struct us_data *us)
 599{
 600	int need_auto_sense;
 601	int result;
 602
 603	/* send the command to the transport layer */
 604	scsi_set_resid(srb, 0);
 605	result = us->transport(srb, us);
 606
 607	/* if the command gets aborted by the higher layers, we need to
 608	 * short-circuit all other processing
 609	 */
 610	if (test_bit(US_FLIDX_TIMED_OUT, &us->dflags)) {
 611		US_DEBUGP("-- command was aborted\n");
 612		srb->result = DID_ABORT << 16;
 613		goto Handle_Errors;
 614	}
 615
 616	/* if there is a transport error, reset and don't auto-sense */
 617	if (result == USB_STOR_TRANSPORT_ERROR) {
 618		US_DEBUGP("-- transport indicates error, resetting\n");
 619		srb->result = DID_ERROR << 16;
 620		goto Handle_Errors;
 621	}
 622
 623	/* if the transport provided its own sense data, don't auto-sense */
 624	if (result == USB_STOR_TRANSPORT_NO_SENSE) {
 625		srb->result = SAM_STAT_CHECK_CONDITION;
 626		last_sector_hacks(us, srb);
 627		return;
 628	}
 629
 630	srb->result = SAM_STAT_GOOD;
 631
 632	/* Determine if we need to auto-sense
 633	 *
 634	 * I normally don't use a flag like this, but it's almost impossible
 635	 * to understand what's going on here if I don't.
 636	 */
 637	need_auto_sense = 0;
 638
 639	/*
 640	 * If we're running the CB transport, which is incapable
 641	 * of determining status on its own, we will auto-sense
 642	 * unless the operation involved a data-in transfer.  Devices
 643	 * can signal most data-in errors by stalling the bulk-in pipe.
 644	 */
 645	if ((us->protocol == USB_PR_CB || us->protocol == USB_PR_DPCM_USB) &&
 646			srb->sc_data_direction != DMA_FROM_DEVICE) {
 647		US_DEBUGP("-- CB transport device requiring auto-sense\n");
 648		need_auto_sense = 1;
 649	}
 650
 651	/*
 652	 * If we have a failure, we're going to do a REQUEST_SENSE 
 653	 * automatically.  Note that we differentiate between a command
 654	 * "failure" and an "error" in the transport mechanism.
 655	 */
 656	if (result == USB_STOR_TRANSPORT_FAILED) {
 657		US_DEBUGP("-- transport indicates command failure\n");
 658		need_auto_sense = 1;
 659	}
 660
 661	/*
 662	 * Determine if this device is SAT by seeing if the
 663	 * command executed successfully.  Otherwise we'll have
 664	 * to wait for at least one CHECK_CONDITION to determine
 665	 * SANE_SENSE support
 666	 */
 667	if (unlikely((srb->cmnd[0] == ATA_16 || srb->cmnd[0] == ATA_12) &&
 668	    result == USB_STOR_TRANSPORT_GOOD &&
 669	    !(us->fflags & US_FL_SANE_SENSE) &&
 670	    !(us->fflags & US_FL_BAD_SENSE) &&
 671	    !(srb->cmnd[2] & 0x20))) {
 672		US_DEBUGP("-- SAT supported, increasing auto-sense\n");
 673		us->fflags |= US_FL_SANE_SENSE;
 674	}
 675
 676	/*
 677	 * A short transfer on a command where we don't expect it
 678	 * is unusual, but it doesn't mean we need to auto-sense.
 679	 */
 680	if ((scsi_get_resid(srb) > 0) &&
 681	    !((srb->cmnd[0] == REQUEST_SENSE) ||
 682	      (srb->cmnd[0] == INQUIRY) ||
 683	      (srb->cmnd[0] == MODE_SENSE) ||
 684	      (srb->cmnd[0] == LOG_SENSE) ||
 685	      (srb->cmnd[0] == MODE_SENSE_10))) {
 686		US_DEBUGP("-- unexpectedly short transfer\n");
 687	}
 688
 689	/* Now, if we need to do the auto-sense, let's do it */
 690	if (need_auto_sense) {
 691		int temp_result;
 692		struct scsi_eh_save ses;
 693		int sense_size = US_SENSE_SIZE;
 
 
 
 694
 695		/* device supports and needs bigger sense buffer */
 696		if (us->fflags & US_FL_SANE_SENSE)
 697			sense_size = ~0;
 698Retry_Sense:
 699		US_DEBUGP("Issuing auto-REQUEST_SENSE\n");
 700
 701		scsi_eh_prep_cmnd(srb, &ses, NULL, 0, sense_size);
 702
 703		/* FIXME: we must do the protocol translation here */
 704		if (us->subclass == USB_SC_RBC || us->subclass == USB_SC_SCSI ||
 705				us->subclass == USB_SC_CYP_ATACB)
 706			srb->cmd_len = 6;
 707		else
 708			srb->cmd_len = 12;
 709
 710		/* issue the auto-sense command */
 711		scsi_set_resid(srb, 0);
 712		temp_result = us->transport(us->srb, us);
 713
 714		/* let's clean up right away */
 715		scsi_eh_restore_cmnd(srb, &ses);
 716
 717		if (test_bit(US_FLIDX_TIMED_OUT, &us->dflags)) {
 718			US_DEBUGP("-- auto-sense aborted\n");
 719			srb->result = DID_ABORT << 16;
 720
 721			/* If SANE_SENSE caused this problem, disable it */
 722			if (sense_size != US_SENSE_SIZE) {
 723				us->fflags &= ~US_FL_SANE_SENSE;
 724				us->fflags |= US_FL_BAD_SENSE;
 725			}
 726			goto Handle_Errors;
 727		}
 728
 729		/* Some devices claim to support larger sense but fail when
 730		 * trying to request it. When a transport failure happens
 731		 * using US_FS_SANE_SENSE, we always retry with a standard
 732		 * (small) sense request. This fixes some USB GSM modems
 733		 */
 734		if (temp_result == USB_STOR_TRANSPORT_FAILED &&
 735				sense_size != US_SENSE_SIZE) {
 736			US_DEBUGP("-- auto-sense failure, retry small sense\n");
 737			sense_size = US_SENSE_SIZE;
 738			us->fflags &= ~US_FL_SANE_SENSE;
 739			us->fflags |= US_FL_BAD_SENSE;
 740			goto Retry_Sense;
 741		}
 742
 743		/* Other failures */
 744		if (temp_result != USB_STOR_TRANSPORT_GOOD) {
 745			US_DEBUGP("-- auto-sense failure\n");
 746
 747			/* we skip the reset if this happens to be a
 748			 * multi-target device, since failure of an
 749			 * auto-sense is perfectly valid
 750			 */
 751			srb->result = DID_ERROR << 16;
 752			if (!(us->fflags & US_FL_SCM_MULT_TARG))
 753				goto Handle_Errors;
 754			return;
 755		}
 756
 757		/* If the sense data returned is larger than 18-bytes then we
 758		 * assume this device supports requesting more in the future.
 759		 * The response code must be 70h through 73h inclusive.
 760		 */
 761		if (srb->sense_buffer[7] > (US_SENSE_SIZE - 8) &&
 762		    !(us->fflags & US_FL_SANE_SENSE) &&
 763		    !(us->fflags & US_FL_BAD_SENSE) &&
 764		    (srb->sense_buffer[0] & 0x7C) == 0x70) {
 765			US_DEBUGP("-- SANE_SENSE support enabled\n");
 766			us->fflags |= US_FL_SANE_SENSE;
 767
 768			/* Indicate to the user that we truncated their sense
 769			 * because we didn't know it supported larger sense.
 770			 */
 771			US_DEBUGP("-- Sense data truncated to %i from %i\n",
 772			          US_SENSE_SIZE,
 773			          srb->sense_buffer[7] + 8);
 774			srb->sense_buffer[7] = (US_SENSE_SIZE - 8);
 775		}
 776
 
 
 
 777		US_DEBUGP("-- Result from auto-sense is %d\n", temp_result);
 778		US_DEBUGP("-- code: 0x%x, key: 0x%x, ASC: 0x%x, ASCQ: 0x%x\n",
 779			  srb->sense_buffer[0],
 780			  srb->sense_buffer[2] & 0xf,
 781			  srb->sense_buffer[12], 
 782			  srb->sense_buffer[13]);
 783#ifdef CONFIG_USB_STORAGE_DEBUG
 784		usb_stor_show_sense(
 785			  srb->sense_buffer[2] & 0xf,
 786			  srb->sense_buffer[12], 
 787			  srb->sense_buffer[13]);
 788#endif
 789
 790		/* set the result so the higher layers expect this data */
 791		srb->result = SAM_STAT_CHECK_CONDITION;
 792
 
 
 
 
 793		/* We often get empty sense data.  This could indicate that
 794		 * everything worked or that there was an unspecified
 795		 * problem.  We have to decide which.
 796		 */
 797		if (	/* Filemark 0, ignore EOM, ILI 0, no sense */
 798				(srb->sense_buffer[2] & 0xaf) == 0 &&
 799			/* No ASC or ASCQ */
 800				srb->sense_buffer[12] == 0 &&
 801				srb->sense_buffer[13] == 0) {
 802
 803			/* If things are really okay, then let's show that.
 804			 * Zero out the sense buffer so the higher layers
 805			 * won't realize we did an unsolicited auto-sense.
 806			 */
 807			if (result == USB_STOR_TRANSPORT_GOOD) {
 808				srb->result = SAM_STAT_GOOD;
 809				srb->sense_buffer[0] = 0x0;
 810
 811			/* If there was a problem, report an unspecified
 812			 * hardware error to prevent the higher layers from
 813			 * entering an infinite retry loop.
 814			 */
 815			} else {
 816				srb->result = DID_ERROR << 16;
 817				srb->sense_buffer[2] = HARDWARE_ERROR;
 
 
 
 818			}
 819		}
 820	}
 821
 822	/*
 823	 * Some devices don't work or return incorrect data the first
 824	 * time they get a READ(10) command, or for the first READ(10)
 825	 * after a media change.  If the INITIAL_READ10 flag is set,
 826	 * keep track of whether READ(10) commands succeed.  If the
 827	 * previous one succeeded and this one failed, set the REDO_READ10
 828	 * flag to force a retry.
 829	 */
 830	if (unlikely((us->fflags & US_FL_INITIAL_READ10) &&
 831			srb->cmnd[0] == READ_10)) {
 832		if (srb->result == SAM_STAT_GOOD) {
 833			set_bit(US_FLIDX_READ10_WORKED, &us->dflags);
 834		} else if (test_bit(US_FLIDX_READ10_WORKED, &us->dflags)) {
 835			clear_bit(US_FLIDX_READ10_WORKED, &us->dflags);
 836			set_bit(US_FLIDX_REDO_READ10, &us->dflags);
 837		}
 838
 839		/*
 840		 * Next, if the REDO_READ10 flag is set, return a result
 841		 * code that will cause the SCSI core to retry the READ(10)
 842		 * command immediately.
 843		 */
 844		if (test_bit(US_FLIDX_REDO_READ10, &us->dflags)) {
 845			clear_bit(US_FLIDX_REDO_READ10, &us->dflags);
 846			srb->result = DID_IMM_RETRY << 16;
 847			srb->sense_buffer[0] = 0;
 848		}
 849	}
 850
 851	/* Did we transfer less than the minimum amount required? */
 852	if ((srb->result == SAM_STAT_GOOD || srb->sense_buffer[2] == 0) &&
 853			scsi_bufflen(srb) - scsi_get_resid(srb) < srb->underflow)
 854		srb->result = DID_ERROR << 16;
 855
 856	last_sector_hacks(us, srb);
 857	return;
 858
 859	/* Error and abort processing: try to resynchronize with the device
 860	 * by issuing a port reset.  If that fails, try a class-specific
 861	 * device reset. */
 862  Handle_Errors:
 863
 864	/* Set the RESETTING bit, and clear the ABORTING bit so that
 865	 * the reset may proceed. */
 866	scsi_lock(us_to_host(us));
 867	set_bit(US_FLIDX_RESETTING, &us->dflags);
 868	clear_bit(US_FLIDX_ABORTING, &us->dflags);
 869	scsi_unlock(us_to_host(us));
 870
 871	/* We must release the device lock because the pre_reset routine
 872	 * will want to acquire it. */
 873	mutex_unlock(&us->dev_mutex);
 874	result = usb_stor_port_reset(us);
 875	mutex_lock(&us->dev_mutex);
 876
 877	if (result < 0) {
 878		scsi_lock(us_to_host(us));
 879		usb_stor_report_device_reset(us);
 880		scsi_unlock(us_to_host(us));
 881		us->transport_reset(us);
 882	}
 883	clear_bit(US_FLIDX_RESETTING, &us->dflags);
 884	last_sector_hacks(us, srb);
 885}
 886
 887/* Stop the current URB transfer */
 888void usb_stor_stop_transport(struct us_data *us)
 889{
 890	US_DEBUGP("%s called\n", __func__);
 891
 892	/* If the state machine is blocked waiting for an URB,
 893	 * let's wake it up.  The test_and_clear_bit() call
 894	 * guarantees that if a URB has just been submitted,
 895	 * it won't be cancelled more than once. */
 896	if (test_and_clear_bit(US_FLIDX_URB_ACTIVE, &us->dflags)) {
 897		US_DEBUGP("-- cancelling URB\n");
 898		usb_unlink_urb(us->current_urb);
 899	}
 900
 901	/* If we are waiting for a scatter-gather operation, cancel it. */
 902	if (test_and_clear_bit(US_FLIDX_SG_ACTIVE, &us->dflags)) {
 903		US_DEBUGP("-- cancelling sg request\n");
 904		usb_sg_cancel(&us->current_sg);
 905	}
 906}
 907
 908/*
 909 * Control/Bulk and Control/Bulk/Interrupt transport
 910 */
 911
 912int usb_stor_CB_transport(struct scsi_cmnd *srb, struct us_data *us)
 913{
 914	unsigned int transfer_length = scsi_bufflen(srb);
 915	unsigned int pipe = 0;
 916	int result;
 917
 918	/* COMMAND STAGE */
 919	/* let's send the command via the control pipe */
 920	result = usb_stor_ctrl_transfer(us, us->send_ctrl_pipe,
 921				      US_CBI_ADSC, 
 922				      USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0, 
 923				      us->ifnum, srb->cmnd, srb->cmd_len);
 924
 925	/* check the return code for the command */
 926	US_DEBUGP("Call to usb_stor_ctrl_transfer() returned %d\n", result);
 927
 928	/* if we stalled the command, it means command failed */
 929	if (result == USB_STOR_XFER_STALLED) {
 930		return USB_STOR_TRANSPORT_FAILED;
 931	}
 932
 933	/* Uh oh... serious problem here */
 934	if (result != USB_STOR_XFER_GOOD) {
 935		return USB_STOR_TRANSPORT_ERROR;
 936	}
 937
 938	/* DATA STAGE */
 939	/* transfer the data payload for this command, if one exists*/
 940	if (transfer_length) {
 941		pipe = srb->sc_data_direction == DMA_FROM_DEVICE ? 
 942				us->recv_bulk_pipe : us->send_bulk_pipe;
 943		result = usb_stor_bulk_srb(us, pipe, srb);
 944		US_DEBUGP("CBI data stage result is 0x%x\n", result);
 945
 946		/* if we stalled the data transfer it means command failed */
 947		if (result == USB_STOR_XFER_STALLED)
 948			return USB_STOR_TRANSPORT_FAILED;
 949		if (result > USB_STOR_XFER_STALLED)
 950			return USB_STOR_TRANSPORT_ERROR;
 951	}
 952
 953	/* STATUS STAGE */
 954
 955	/* NOTE: CB does not have a status stage.  Silly, I know.  So
 956	 * we have to catch this at a higher level.
 957	 */
 958	if (us->protocol != USB_PR_CBI)
 959		return USB_STOR_TRANSPORT_GOOD;
 960
 961	result = usb_stor_intr_transfer(us, us->iobuf, 2);
 962	US_DEBUGP("Got interrupt data (0x%x, 0x%x)\n", 
 963			us->iobuf[0], us->iobuf[1]);
 964	if (result != USB_STOR_XFER_GOOD)
 965		return USB_STOR_TRANSPORT_ERROR;
 966
 967	/* UFI gives us ASC and ASCQ, like a request sense
 968	 *
 969	 * REQUEST_SENSE and INQUIRY don't affect the sense data on UFI
 970	 * devices, so we ignore the information for those commands.  Note
 971	 * that this means we could be ignoring a real error on these
 972	 * commands, but that can't be helped.
 973	 */
 974	if (us->subclass == USB_SC_UFI) {
 975		if (srb->cmnd[0] == REQUEST_SENSE ||
 976		    srb->cmnd[0] == INQUIRY)
 977			return USB_STOR_TRANSPORT_GOOD;
 978		if (us->iobuf[0])
 979			goto Failed;
 980		return USB_STOR_TRANSPORT_GOOD;
 981	}
 982
 983	/* If not UFI, we interpret the data as a result code 
 984	 * The first byte should always be a 0x0.
 985	 *
 986	 * Some bogus devices don't follow that rule.  They stuff the ASC
 987	 * into the first byte -- so if it's non-zero, call it a failure.
 988	 */
 989	if (us->iobuf[0]) {
 990		US_DEBUGP("CBI IRQ data showed reserved bType 0x%x\n",
 991				us->iobuf[0]);
 992		goto Failed;
 993
 994	}
 995
 996	/* The second byte & 0x0F should be 0x0 for good, otherwise error */
 997	switch (us->iobuf[1] & 0x0F) {
 998		case 0x00: 
 999			return USB_STOR_TRANSPORT_GOOD;
1000		case 0x01: 
1001			goto Failed;
1002	}
1003	return USB_STOR_TRANSPORT_ERROR;
1004
1005	/* the CBI spec requires that the bulk pipe must be cleared
1006	 * following any data-in/out command failure (section 2.4.3.1.3)
1007	 */
1008  Failed:
1009	if (pipe)
1010		usb_stor_clear_halt(us, pipe);
1011	return USB_STOR_TRANSPORT_FAILED;
1012}
1013EXPORT_SYMBOL_GPL(usb_stor_CB_transport);
1014
1015/*
1016 * Bulk only transport
1017 */
1018
1019/* Determine what the maximum LUN supported is */
1020int usb_stor_Bulk_max_lun(struct us_data *us)
1021{
1022	int result;
1023
1024	/* issue the command */
1025	us->iobuf[0] = 0;
1026	result = usb_stor_control_msg(us, us->recv_ctrl_pipe,
1027				 US_BULK_GET_MAX_LUN, 
1028				 USB_DIR_IN | USB_TYPE_CLASS | 
1029				 USB_RECIP_INTERFACE,
1030				 0, us->ifnum, us->iobuf, 1, 10*HZ);
1031
1032	US_DEBUGP("GetMaxLUN command result is %d, data is %d\n", 
1033		  result, us->iobuf[0]);
1034
1035	/* if we have a successful request, return the result */
1036	if (result > 0)
1037		return us->iobuf[0];
1038
1039	/*
1040	 * Some devices don't like GetMaxLUN.  They may STALL the control
1041	 * pipe, they may return a zero-length result, they may do nothing at
1042	 * all and timeout, or they may fail in even more bizarrely creative
1043	 * ways.  In these cases the best approach is to use the default
1044	 * value: only one LUN.
1045	 */
1046	return 0;
1047}
1048
1049int usb_stor_Bulk_transport(struct scsi_cmnd *srb, struct us_data *us)
1050{
1051	struct bulk_cb_wrap *bcb = (struct bulk_cb_wrap *) us->iobuf;
1052	struct bulk_cs_wrap *bcs = (struct bulk_cs_wrap *) us->iobuf;
1053	unsigned int transfer_length = scsi_bufflen(srb);
1054	unsigned int residue;
1055	int result;
1056	int fake_sense = 0;
1057	unsigned int cswlen;
1058	unsigned int cbwlen = US_BULK_CB_WRAP_LEN;
1059
1060	/* Take care of BULK32 devices; set extra byte to 0 */
1061	if (unlikely(us->fflags & US_FL_BULK32)) {
1062		cbwlen = 32;
1063		us->iobuf[31] = 0;
1064	}
1065
1066	/* set up the command wrapper */
1067	bcb->Signature = cpu_to_le32(US_BULK_CB_SIGN);
1068	bcb->DataTransferLength = cpu_to_le32(transfer_length);
1069	bcb->Flags = srb->sc_data_direction == DMA_FROM_DEVICE ? 1 << 7 : 0;
 
1070	bcb->Tag = ++us->tag;
1071	bcb->Lun = srb->device->lun;
1072	if (us->fflags & US_FL_SCM_MULT_TARG)
1073		bcb->Lun |= srb->device->id << 4;
1074	bcb->Length = srb->cmd_len;
1075
1076	/* copy the command payload */
1077	memset(bcb->CDB, 0, sizeof(bcb->CDB));
1078	memcpy(bcb->CDB, srb->cmnd, bcb->Length);
1079
1080	/* send it to out endpoint */
1081	US_DEBUGP("Bulk Command S 0x%x T 0x%x L %d F %d Trg %d LUN %d CL %d\n",
1082			le32_to_cpu(bcb->Signature), bcb->Tag,
1083			le32_to_cpu(bcb->DataTransferLength), bcb->Flags,
1084			(bcb->Lun >> 4), (bcb->Lun & 0x0F), 
1085			bcb->Length);
1086	result = usb_stor_bulk_transfer_buf(us, us->send_bulk_pipe,
1087				bcb, cbwlen, NULL);
1088	US_DEBUGP("Bulk command transfer result=%d\n", result);
1089	if (result != USB_STOR_XFER_GOOD)
1090		return USB_STOR_TRANSPORT_ERROR;
1091
1092	/* DATA STAGE */
1093	/* send/receive data payload, if there is any */
1094
1095	/* Some USB-IDE converter chips need a 100us delay between the
1096	 * command phase and the data phase.  Some devices need a little
1097	 * more than that, probably because of clock rate inaccuracies. */
1098	if (unlikely(us->fflags & US_FL_GO_SLOW))
1099		udelay(125);
1100
1101	if (transfer_length) {
1102		unsigned int pipe = srb->sc_data_direction == DMA_FROM_DEVICE ? 
1103				us->recv_bulk_pipe : us->send_bulk_pipe;
1104		result = usb_stor_bulk_srb(us, pipe, srb);
1105		US_DEBUGP("Bulk data transfer result 0x%x\n", result);
1106		if (result == USB_STOR_XFER_ERROR)
1107			return USB_STOR_TRANSPORT_ERROR;
1108
1109		/* If the device tried to send back more data than the
1110		 * amount requested, the spec requires us to transfer
1111		 * the CSW anyway.  Since there's no point retrying the
1112		 * the command, we'll return fake sense data indicating
1113		 * Illegal Request, Invalid Field in CDB.
1114		 */
1115		if (result == USB_STOR_XFER_LONG)
1116			fake_sense = 1;
1117	}
1118
1119	/* See flow chart on pg 15 of the Bulk Only Transport spec for
1120	 * an explanation of how this code works.
1121	 */
1122
1123	/* get CSW for device status */
1124	US_DEBUGP("Attempting to get CSW...\n");
1125	result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
1126				bcs, US_BULK_CS_WRAP_LEN, &cswlen);
1127
1128	/* Some broken devices add unnecessary zero-length packets to the
1129	 * end of their data transfers.  Such packets show up as 0-length
1130	 * CSWs.  If we encounter such a thing, try to read the CSW again.
1131	 */
1132	if (result == USB_STOR_XFER_SHORT && cswlen == 0) {
1133		US_DEBUGP("Received 0-length CSW; retrying...\n");
1134		result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
1135				bcs, US_BULK_CS_WRAP_LEN, &cswlen);
1136	}
1137
1138	/* did the attempt to read the CSW fail? */
1139	if (result == USB_STOR_XFER_STALLED) {
1140
1141		/* get the status again */
1142		US_DEBUGP("Attempting to get CSW (2nd try)...\n");
1143		result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
1144				bcs, US_BULK_CS_WRAP_LEN, NULL);
1145	}
1146
1147	/* if we still have a failure at this point, we're in trouble */
1148	US_DEBUGP("Bulk status result = %d\n", result);
1149	if (result != USB_STOR_XFER_GOOD)
1150		return USB_STOR_TRANSPORT_ERROR;
1151
1152	/* check bulk status */
1153	residue = le32_to_cpu(bcs->Residue);
1154	US_DEBUGP("Bulk Status S 0x%x T 0x%x R %u Stat 0x%x\n",
1155			le32_to_cpu(bcs->Signature), bcs->Tag, 
1156			residue, bcs->Status);
1157	if (!(bcs->Tag == us->tag || (us->fflags & US_FL_BULK_IGNORE_TAG)) ||
1158		bcs->Status > US_BULK_STAT_PHASE) {
1159		US_DEBUGP("Bulk logical error\n");
1160		return USB_STOR_TRANSPORT_ERROR;
1161	}
1162
1163	/* Some broken devices report odd signatures, so we do not check them
1164	 * for validity against the spec. We store the first one we see,
1165	 * and check subsequent transfers for validity against this signature.
1166	 */
1167	if (!us->bcs_signature) {
1168		us->bcs_signature = bcs->Signature;
1169		if (us->bcs_signature != cpu_to_le32(US_BULK_CS_SIGN))
1170			US_DEBUGP("Learnt BCS signature 0x%08X\n",
1171					le32_to_cpu(us->bcs_signature));
1172	} else if (bcs->Signature != us->bcs_signature) {
1173		US_DEBUGP("Signature mismatch: got %08X, expecting %08X\n",
1174			  le32_to_cpu(bcs->Signature),
1175			  le32_to_cpu(us->bcs_signature));
1176		return USB_STOR_TRANSPORT_ERROR;
1177	}
1178
1179	/* try to compute the actual residue, based on how much data
1180	 * was really transferred and what the device tells us */
1181	if (residue && !(us->fflags & US_FL_IGNORE_RESIDUE)) {
1182
1183		/* Heuristically detect devices that generate bogus residues
1184		 * by seeing what happens with INQUIRY and READ CAPACITY
1185		 * commands.
1186		 */
1187		if (bcs->Status == US_BULK_STAT_OK &&
1188				scsi_get_resid(srb) == 0 &&
1189					((srb->cmnd[0] == INQUIRY &&
1190						transfer_length == 36) ||
1191					(srb->cmnd[0] == READ_CAPACITY &&
1192						transfer_length == 8))) {
1193			us->fflags |= US_FL_IGNORE_RESIDUE;
1194
1195		} else {
1196			residue = min(residue, transfer_length);
1197			scsi_set_resid(srb, max(scsi_get_resid(srb),
1198			                                       (int) residue));
1199		}
1200	}
1201
1202	/* based on the status code, we report good or bad */
1203	switch (bcs->Status) {
1204		case US_BULK_STAT_OK:
1205			/* device babbled -- return fake sense data */
1206			if (fake_sense) {
1207				memcpy(srb->sense_buffer, 
1208				       usb_stor_sense_invalidCDB, 
1209				       sizeof(usb_stor_sense_invalidCDB));
1210				return USB_STOR_TRANSPORT_NO_SENSE;
1211			}
1212
1213			/* command good -- note that data could be short */
1214			return USB_STOR_TRANSPORT_GOOD;
1215
1216		case US_BULK_STAT_FAIL:
1217			/* command failed */
1218			return USB_STOR_TRANSPORT_FAILED;
1219
1220		case US_BULK_STAT_PHASE:
1221			/* phase error -- note that a transport reset will be
1222			 * invoked by the invoke_transport() function
1223			 */
1224			return USB_STOR_TRANSPORT_ERROR;
1225	}
1226
1227	/* we should never get here, but if we do, we're in trouble */
1228	return USB_STOR_TRANSPORT_ERROR;
1229}
1230EXPORT_SYMBOL_GPL(usb_stor_Bulk_transport);
1231
1232/***********************************************************************
1233 * Reset routines
1234 ***********************************************************************/
1235
1236/* This is the common part of the device reset code.
1237 *
1238 * It's handy that every transport mechanism uses the control endpoint for
1239 * resets.
1240 *
1241 * Basically, we send a reset with a 5-second timeout, so we don't get
1242 * jammed attempting to do the reset.
1243 */
1244static int usb_stor_reset_common(struct us_data *us,
1245		u8 request, u8 requesttype,
1246		u16 value, u16 index, void *data, u16 size)
1247{
1248	int result;
1249	int result2;
1250
1251	if (test_bit(US_FLIDX_DISCONNECTING, &us->dflags)) {
1252		US_DEBUGP("No reset during disconnect\n");
1253		return -EIO;
1254	}
1255
1256	result = usb_stor_control_msg(us, us->send_ctrl_pipe,
1257			request, requesttype, value, index, data, size,
1258			5*HZ);
1259	if (result < 0) {
1260		US_DEBUGP("Soft reset failed: %d\n", result);
1261		return result;
1262	}
1263
1264	/* Give the device some time to recover from the reset,
1265	 * but don't delay disconnect processing. */
1266	wait_event_interruptible_timeout(us->delay_wait,
1267			test_bit(US_FLIDX_DISCONNECTING, &us->dflags),
1268			HZ*6);
1269	if (test_bit(US_FLIDX_DISCONNECTING, &us->dflags)) {
1270		US_DEBUGP("Reset interrupted by disconnect\n");
1271		return -EIO;
1272	}
1273
1274	US_DEBUGP("Soft reset: clearing bulk-in endpoint halt\n");
1275	result = usb_stor_clear_halt(us, us->recv_bulk_pipe);
1276
1277	US_DEBUGP("Soft reset: clearing bulk-out endpoint halt\n");
1278	result2 = usb_stor_clear_halt(us, us->send_bulk_pipe);
1279
1280	/* return a result code based on the result of the clear-halts */
1281	if (result >= 0)
1282		result = result2;
1283	if (result < 0)
1284		US_DEBUGP("Soft reset failed\n");
1285	else
1286		US_DEBUGP("Soft reset done\n");
1287	return result;
1288}
1289
1290/* This issues a CB[I] Reset to the device in question
1291 */
1292#define CB_RESET_CMD_SIZE	12
1293
1294int usb_stor_CB_reset(struct us_data *us)
1295{
1296	US_DEBUGP("%s called\n", __func__);
1297
1298	memset(us->iobuf, 0xFF, CB_RESET_CMD_SIZE);
1299	us->iobuf[0] = SEND_DIAGNOSTIC;
1300	us->iobuf[1] = 4;
1301	return usb_stor_reset_common(us, US_CBI_ADSC, 
1302				 USB_TYPE_CLASS | USB_RECIP_INTERFACE,
1303				 0, us->ifnum, us->iobuf, CB_RESET_CMD_SIZE);
1304}
1305EXPORT_SYMBOL_GPL(usb_stor_CB_reset);
1306
1307/* This issues a Bulk-only Reset to the device in question, including
1308 * clearing the subsequent endpoint halts that may occur.
1309 */
1310int usb_stor_Bulk_reset(struct us_data *us)
1311{
1312	US_DEBUGP("%s called\n", __func__);
1313
1314	return usb_stor_reset_common(us, US_BULK_RESET_REQUEST, 
1315				 USB_TYPE_CLASS | USB_RECIP_INTERFACE,
1316				 0, us->ifnum, NULL, 0);
1317}
1318EXPORT_SYMBOL_GPL(usb_stor_Bulk_reset);
1319
1320/* Issue a USB port reset to the device.  The caller must not hold
1321 * us->dev_mutex.
1322 */
1323int usb_stor_port_reset(struct us_data *us)
1324{
1325	int result;
1326
1327	/*for these devices we must use the class specific method */
1328	if (us->pusb_dev->quirks & USB_QUIRK_RESET_MORPHS)
1329		return -EPERM;
1330
1331	result = usb_lock_device_for_reset(us->pusb_dev, us->pusb_intf);
1332	if (result < 0)
1333		US_DEBUGP("unable to lock device for reset: %d\n", result);
1334	else {
1335		/* Were we disconnected while waiting for the lock? */
1336		if (test_bit(US_FLIDX_DISCONNECTING, &us->dflags)) {
1337			result = -EIO;
1338			US_DEBUGP("No reset during disconnect\n");
1339		} else {
1340			result = usb_reset_device(us->pusb_dev);
1341			US_DEBUGP("usb_reset_device returns %d\n",
1342					result);
1343		}
1344		usb_unlock_device(us->pusb_dev);
1345	}
1346	return result;
1347}