1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Driver for USB Mass Storage compliant devices
4  *
5  * Current development and maintenance by:
6  *   (c) 1999-2002 Matthew Dharm (mdharm-usb@one-eyed-alien.net)
7  *
8  * Developed with the assistance of:
9  *   (c) 2000 David L. Brown, Jr. (usb-storage@davidb.org)
10  *   (c) 2000 Stephen J. Gowdy (SGowdy@lbl.gov)
11  *   (c) 2002 Alan Stern <stern@rowland.org>
12  *
13  * Initial work by:
14  *   (c) 1999 Michael Gee (michael@linuxspecific.com)
15  *
16  * This driver is based on the 'USB Mass Storage Class' document. This
17  * describes in detail the protocol used to communicate with such
18  * devices.  Clearly, the designers had SCSI and ATAPI commands in
19  * mind when they created this document.  The commands are all very
20  * similar to commands in the SCSI-II and ATAPI specifications.
21  *
22  * It is important to note that in a number of cases this class
23  * exhibits class-specific exemptions from the USB specification.
24  * Notably the usage of NAK, STALL and ACK differs from the norm, in
25  * that they are used to communicate wait, failed and OK on commands.
26  *
27  * Also, for certain devices, the interrupt endpoint is used to convey
28  * status of a command.
29  */
30 
31 #include <linux/sched.h>
32 #include <linux/gfp.h>
33 #include <linux/errno.h>
34 #include <linux/export.h>
35 
36 #include <linux/usb/quirks.h>
37 
38 #include <scsi/scsi.h>
39 #include <scsi/scsi_eh.h>
40 #include <scsi/scsi_device.h>
41 
42 #include "usb.h"
43 #include "transport.h"
44 #include "protocol.h"
45 #include "scsiglue.h"
46 #include "debug.h"
47 
48 #include <linux/blkdev.h>
49 #include "../../scsi/sd.h"
50 
51 
52 /***********************************************************************
53  * Data transfer routines
54  ***********************************************************************/
55 
56 /*
57  * This is subtle, so pay attention:
58  * ---------------------------------
59  * We're very concerned about races with a command abort.  Hanging this code
60  * is a sure fire way to hang the kernel.  (Note that this discussion applies
61  * only to transactions resulting from a scsi queued-command, since only
62  * these transactions are subject to a scsi abort.  Other transactions, such
63  * as those occurring during device-specific initialization, must be handled
64  * by a separate code path.)
65  *
66  * The abort function (usb_storage_command_abort() in scsiglue.c) first
67  * sets the machine state and the ABORTING bit in us->dflags to prevent
68  * new URBs from being submitted.  It then calls usb_stor_stop_transport()
69  * below, which atomically tests-and-clears the URB_ACTIVE bit in us->dflags
70  * to see if the current_urb needs to be stopped.  Likewise, the SG_ACTIVE
71  * bit is tested to see if the current_sg scatter-gather request needs to be
72  * stopped.  The timeout callback routine does much the same thing.
73  *
74  * When a disconnect occurs, the DISCONNECTING bit in us->dflags is set to
75  * prevent new URBs from being submitted, and usb_stor_stop_transport() is
76  * called to stop any ongoing requests.
77  *
78  * The submit function first verifies that the submitting is allowed
79  * (neither ABORTING nor DISCONNECTING bits are set) and that the submit
80  * completes without errors, and only then sets the URB_ACTIVE bit.  This
81  * prevents the stop_transport() function from trying to cancel the URB
82  * while the submit call is underway.  Next, the submit function must test
83  * the flags to see if an abort or disconnect occurred during the submission
84  * or before the URB_ACTIVE bit was set.  If so, it's essential to cancel
85  * the URB if it hasn't been cancelled already (i.e., if the URB_ACTIVE bit
86  * is still set).  Either way, the function must then wait for the URB to
87  * finish.  Note that the URB can still be in progress even after a call to
88  * usb_unlink_urb() returns.
89  *
90  * The idea is that (1) once the ABORTING or DISCONNECTING bit is set,
91  * either the stop_transport() function or the submitting function
92  * is guaranteed to call usb_unlink_urb() for an active URB,
93  * and (2) test_and_clear_bit() prevents usb_unlink_urb() from being
94  * called more than once or from being called during usb_submit_urb().
95  */
96 
97 /*
98  * This is the completion handler which will wake us up when an URB
99  * completes.
100  */
usb_stor_blocking_completion(struct urb * urb)101 static void usb_stor_blocking_completion(struct urb *urb)
102 {
103 	struct completion *urb_done_ptr = urb->context;
104 
105 	complete(urb_done_ptr);
106 }
107 
108 /*
109  * This is the common part of the URB message submission code
110  *
111  * All URBs from the usb-storage driver involved in handling a queued scsi
112  * command _must_ pass through this function (or something like it) for the
113  * abort mechanisms to work properly.
114  */
usb_stor_msg_common(struct us_data * us,int timeout)115 static int usb_stor_msg_common(struct us_data *us, int timeout)
116 {
117 	struct completion urb_done;
118 	long timeleft;
119 	int status;
120 
121 	/* don't submit URBs during abort processing */
122 	if (test_bit(US_FLIDX_ABORTING, &us->dflags))
123 		return -EIO;
124 
125 	/* set up data structures for the wakeup system */
126 	init_completion(&urb_done);
127 
128 	/* fill the common fields in the URB */
129 	us->current_urb->context = &urb_done;
130 	us->current_urb->transfer_flags = 0;
131 
132 	/*
133 	 * we assume that if transfer_buffer isn't us->iobuf then it
134 	 * hasn't been mapped for DMA.  Yes, this is clunky, but it's
135 	 * easier than always having the caller tell us whether the
136 	 * transfer buffer has already been mapped.
137 	 */
138 	if (us->current_urb->transfer_buffer == us->iobuf)
139 		us->current_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
140 	us->current_urb->transfer_dma = us->iobuf_dma;
141 
142 	/* submit the URB */
143 	status = usb_submit_urb(us->current_urb, GFP_NOIO);
144 	if (status) {
145 		/* something went wrong */
146 		return status;
147 	}
148 
149 	/*
150 	 * since the URB has been submitted successfully, it's now okay
151 	 * to cancel it
152 	 */
153 	set_bit(US_FLIDX_URB_ACTIVE, &us->dflags);
154 
155 	/* did an abort occur during the submission? */
156 	if (test_bit(US_FLIDX_ABORTING, &us->dflags)) {
157 
158 		/* cancel the URB, if it hasn't been cancelled already */
159 		if (test_and_clear_bit(US_FLIDX_URB_ACTIVE, &us->dflags)) {
160 			usb_stor_dbg(us, "-- cancelling URB\n");
161 			usb_unlink_urb(us->current_urb);
162 		}
163 	}
164 
165 	/* wait for the completion of the URB */
166 	timeleft = wait_for_completion_interruptible_timeout(
167 			&urb_done, timeout ? : MAX_SCHEDULE_TIMEOUT);
168 
169 	clear_bit(US_FLIDX_URB_ACTIVE, &us->dflags);
170 
171 	if (timeleft <= 0) {
172 		usb_stor_dbg(us, "%s -- cancelling URB\n",
173 			     timeleft == 0 ? "Timeout" : "Signal");
174 		usb_kill_urb(us->current_urb);
175 	}
176 
177 	/* return the URB status */
178 	return us->current_urb->status;
179 }
180 
181 /*
182  * Transfer one control message, with timeouts, and allowing early
183  * termination.  Return codes are usual -Exxx, *not* USB_STOR_XFER_xxx.
184  */
usb_stor_control_msg(struct us_data * us,unsigned int pipe,u8 request,u8 requesttype,u16 value,u16 index,void * data,u16 size,int timeout)185 int usb_stor_control_msg(struct us_data *us, unsigned int pipe,
186 		 u8 request, u8 requesttype, u16 value, u16 index,
187 		 void *data, u16 size, int timeout)
188 {
189 	int status;
190 
191 	usb_stor_dbg(us, "rq=%02x rqtype=%02x value=%04x index=%02x len=%u\n",
192 		     request, requesttype, value, index, size);
193 
194 	/* fill in the devrequest structure */
195 	us->cr->bRequestType = requesttype;
196 	us->cr->bRequest = request;
197 	us->cr->wValue = cpu_to_le16(value);
198 	us->cr->wIndex = cpu_to_le16(index);
199 	us->cr->wLength = cpu_to_le16(size);
200 
201 	/* fill and submit the URB */
202 	usb_fill_control_urb(us->current_urb, us->pusb_dev, pipe,
203 			 (unsigned char*) us->cr, data, size,
204 			 usb_stor_blocking_completion, NULL);
205 	status = usb_stor_msg_common(us, timeout);
206 
207 	/* return the actual length of the data transferred if no error */
208 	if (status == 0)
209 		status = us->current_urb->actual_length;
210 	return status;
211 }
212 EXPORT_SYMBOL_GPL(usb_stor_control_msg);
213 
214 /*
215  * This is a version of usb_clear_halt() that allows early termination and
216  * doesn't read the status from the device -- this is because some devices
217  * crash their internal firmware when the status is requested after a halt.
218  *
219  * A definitive list of these 'bad' devices is too difficult to maintain or
220  * make complete enough to be useful.  This problem was first observed on the
221  * Hagiwara FlashGate DUAL unit.  However, bus traces reveal that neither
222  * MacOS nor Windows checks the status after clearing a halt.
223  *
224  * Since many vendors in this space limit their testing to interoperability
225  * with these two OSes, specification violations like this one are common.
226  */
usb_stor_clear_halt(struct us_data * us,unsigned int pipe)227 int usb_stor_clear_halt(struct us_data *us, unsigned int pipe)
228 {
229 	int result;
230 	int endp = usb_pipeendpoint(pipe);
231 
232 	if (usb_pipein (pipe))
233 		endp |= USB_DIR_IN;
234 
235 	result = usb_stor_control_msg(us, us->send_ctrl_pipe,
236 		USB_REQ_CLEAR_FEATURE, USB_RECIP_ENDPOINT,
237 		USB_ENDPOINT_HALT, endp,
238 		NULL, 0, 3*HZ);
239 
240 	if (result >= 0)
241 		usb_reset_endpoint(us->pusb_dev, endp);
242 
243 	usb_stor_dbg(us, "result = %d\n", result);
244 	return result;
245 }
246 EXPORT_SYMBOL_GPL(usb_stor_clear_halt);
247 
248 
249 /*
250  * Interpret the results of a URB transfer
251  *
252  * This function prints appropriate debugging messages, clears halts on
253  * non-control endpoints, and translates the status to the corresponding
254  * USB_STOR_XFER_xxx return code.
255  */
interpret_urb_result(struct us_data * us,unsigned int pipe,unsigned int length,int result,unsigned int partial)256 static int interpret_urb_result(struct us_data *us, unsigned int pipe,
257 		unsigned int length, int result, unsigned int partial)
258 {
259 	usb_stor_dbg(us, "Status code %d; transferred %u/%u\n",
260 		     result, partial, length);
261 	switch (result) {
262 
263 	/* no error code; did we send all the data? */
264 	case 0:
265 		if (partial != length) {
266 			usb_stor_dbg(us, "-- short transfer\n");
267 			return USB_STOR_XFER_SHORT;
268 		}
269 
270 		usb_stor_dbg(us, "-- transfer complete\n");
271 		return USB_STOR_XFER_GOOD;
272 
273 	/* stalled */
274 	case -EPIPE:
275 		/*
276 		 * for control endpoints, (used by CB[I]) a stall indicates
277 		 * a failed command
278 		 */
279 		if (usb_pipecontrol(pipe)) {
280 			usb_stor_dbg(us, "-- stall on control pipe\n");
281 			return USB_STOR_XFER_STALLED;
282 		}
283 
284 		/* for other sorts of endpoint, clear the stall */
285 		usb_stor_dbg(us, "clearing endpoint halt for pipe 0x%x\n",
286 			     pipe);
287 		if (usb_stor_clear_halt(us, pipe) < 0)
288 			return USB_STOR_XFER_ERROR;
289 		return USB_STOR_XFER_STALLED;
290 
291 	/* babble - the device tried to send more than we wanted to read */
292 	case -EOVERFLOW:
293 		usb_stor_dbg(us, "-- babble\n");
294 		return USB_STOR_XFER_LONG;
295 
296 	/* the transfer was cancelled by abort, disconnect, or timeout */
297 	case -ECONNRESET:
298 		usb_stor_dbg(us, "-- transfer cancelled\n");
299 		return USB_STOR_XFER_ERROR;
300 
301 	/* short scatter-gather read transfer */
302 	case -EREMOTEIO:
303 		usb_stor_dbg(us, "-- short read transfer\n");
304 		return USB_STOR_XFER_SHORT;
305 
306 	/* abort or disconnect in progress */
307 	case -EIO:
308 		usb_stor_dbg(us, "-- abort or disconnect in progress\n");
309 		return USB_STOR_XFER_ERROR;
310 
311 	/* the catch-all error case */
312 	default:
313 		usb_stor_dbg(us, "-- unknown error\n");
314 		return USB_STOR_XFER_ERROR;
315 	}
316 }
317 
318 /*
319  * Transfer one control message, without timeouts, but allowing early
320  * termination.  Return codes are USB_STOR_XFER_xxx.
321  */
usb_stor_ctrl_transfer(struct us_data * us,unsigned int pipe,u8 request,u8 requesttype,u16 value,u16 index,void * data,u16 size)322 int usb_stor_ctrl_transfer(struct us_data *us, unsigned int pipe,
323 		u8 request, u8 requesttype, u16 value, u16 index,
324 		void *data, u16 size)
325 {
326 	int result;
327 
328 	usb_stor_dbg(us, "rq=%02x rqtype=%02x value=%04x index=%02x len=%u\n",
329 		     request, requesttype, value, index, size);
330 
331 	/* fill in the devrequest structure */
332 	us->cr->bRequestType = requesttype;
333 	us->cr->bRequest = request;
334 	us->cr->wValue = cpu_to_le16(value);
335 	us->cr->wIndex = cpu_to_le16(index);
336 	us->cr->wLength = cpu_to_le16(size);
337 
338 	/* fill and submit the URB */
339 	usb_fill_control_urb(us->current_urb, us->pusb_dev, pipe,
340 			 (unsigned char*) us->cr, data, size,
341 			 usb_stor_blocking_completion, NULL);
342 	result = usb_stor_msg_common(us, 0);
343 
344 	return interpret_urb_result(us, pipe, size, result,
345 			us->current_urb->actual_length);
346 }
347 EXPORT_SYMBOL_GPL(usb_stor_ctrl_transfer);
348 
349 /*
350  * Receive one interrupt buffer, without timeouts, but allowing early
351  * termination.  Return codes are USB_STOR_XFER_xxx.
352  *
353  * This routine always uses us->recv_intr_pipe as the pipe and
354  * us->ep_bInterval as the interrupt interval.
355  */
usb_stor_intr_transfer(struct us_data * us,void * buf,unsigned int length)356 static int usb_stor_intr_transfer(struct us_data *us, void *buf,
357 				  unsigned int length)
358 {
359 	int result;
360 	unsigned int pipe = us->recv_intr_pipe;
361 	unsigned int maxp;
362 
363 	usb_stor_dbg(us, "xfer %u bytes\n", length);
364 
365 	/* calculate the max packet size */
366 	maxp = usb_maxpacket(us->pusb_dev, pipe);
367 	if (maxp > length)
368 		maxp = length;
369 
370 	/* fill and submit the URB */
371 	usb_fill_int_urb(us->current_urb, us->pusb_dev, pipe, buf,
372 			maxp, usb_stor_blocking_completion, NULL,
373 			us->ep_bInterval);
374 	result = usb_stor_msg_common(us, 0);
375 
376 	return interpret_urb_result(us, pipe, length, result,
377 			us->current_urb->actual_length);
378 }
379 
380 /*
381  * Transfer one buffer via bulk pipe, without timeouts, but allowing early
382  * termination.  Return codes are USB_STOR_XFER_xxx.  If the bulk pipe
383  * stalls during the transfer, the halt is automatically cleared.
384  */
usb_stor_bulk_transfer_buf(struct us_data * us,unsigned int pipe,void * buf,unsigned int length,unsigned int * act_len)385 int usb_stor_bulk_transfer_buf(struct us_data *us, unsigned int pipe,
386 	void *buf, unsigned int length, unsigned int *act_len)
387 {
388 	int result;
389 
390 	usb_stor_dbg(us, "xfer %u bytes\n", length);
391 
392 	/* fill and submit the URB */
393 	usb_fill_bulk_urb(us->current_urb, us->pusb_dev, pipe, buf, length,
394 		      usb_stor_blocking_completion, NULL);
395 	result = usb_stor_msg_common(us, 0);
396 
397 	/* store the actual length of the data transferred */
398 	if (act_len)
399 		*act_len = us->current_urb->actual_length;
400 	return interpret_urb_result(us, pipe, length, result,
401 			us->current_urb->actual_length);
402 }
403 EXPORT_SYMBOL_GPL(usb_stor_bulk_transfer_buf);
404 
405 /*
406  * Transfer a scatter-gather list via bulk transfer
407  *
408  * This function does basically the same thing as usb_stor_bulk_transfer_buf()
409  * above, but it uses the usbcore scatter-gather library.
410  */
usb_stor_bulk_transfer_sglist(struct us_data * us,unsigned int pipe,struct scatterlist * sg,int num_sg,unsigned int length,unsigned int * act_len)411 static int usb_stor_bulk_transfer_sglist(struct us_data *us, unsigned int pipe,
412 		struct scatterlist *sg, int num_sg, unsigned int length,
413 		unsigned int *act_len)
414 {
415 	int result;
416 
417 	/* don't submit s-g requests during abort processing */
418 	if (test_bit(US_FLIDX_ABORTING, &us->dflags))
419 		goto usb_stor_xfer_error;
420 
421 	/* initialize the scatter-gather request block */
422 	usb_stor_dbg(us, "xfer %u bytes, %d entries\n", length, num_sg);
423 	result = usb_sg_init(&us->current_sg, us->pusb_dev, pipe, 0,
424 			sg, num_sg, length, GFP_NOIO);
425 	if (result) {
426 		usb_stor_dbg(us, "usb_sg_init returned %d\n", result);
427 		goto usb_stor_xfer_error;
428 	}
429 
430 	/*
431 	 * since the block has been initialized successfully, it's now
432 	 * okay to cancel it
433 	 */
434 	set_bit(US_FLIDX_SG_ACTIVE, &us->dflags);
435 
436 	/* did an abort occur during the submission? */
437 	if (test_bit(US_FLIDX_ABORTING, &us->dflags)) {
438 
439 		/* cancel the request, if it hasn't been cancelled already */
440 		if (test_and_clear_bit(US_FLIDX_SG_ACTIVE, &us->dflags)) {
441 			usb_stor_dbg(us, "-- cancelling sg request\n");
442 			usb_sg_cancel(&us->current_sg);
443 		}
444 	}
445 
446 	/* wait for the completion of the transfer */
447 	usb_sg_wait(&us->current_sg);
448 	clear_bit(US_FLIDX_SG_ACTIVE, &us->dflags);
449 
450 	result = us->current_sg.status;
451 	if (act_len)
452 		*act_len = us->current_sg.bytes;
453 	return interpret_urb_result(us, pipe, length, result,
454 			us->current_sg.bytes);
455 
456 usb_stor_xfer_error:
457 	if (act_len)
458 		*act_len = 0;
459 	return USB_STOR_XFER_ERROR;
460 }
461 
462 /*
463  * Common used function. Transfer a complete command
464  * via usb_stor_bulk_transfer_sglist() above. Set cmnd resid
465  */
usb_stor_bulk_srb(struct us_data * us,unsigned int pipe,struct scsi_cmnd * srb)466 int 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 }
477 EXPORT_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  */
usb_stor_bulk_transfer_sg(struct us_data * us,unsigned int pipe,void * buf,unsigned int length_left,int use_sg,int * residual)488 int 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 }
513 EXPORT_SYMBOL_GPL(usb_stor_bulk_transfer_sg);
514 
515 /***********************************************************************
516  * Transport routines
517  ***********************************************************************/
518 
519 /*
520  * There are so many devices that report the capacity incorrectly,
521  * this routine was written to counteract some of the resulting
522  * problems.
523  */
last_sector_hacks(struct us_data * us,struct scsi_cmnd * srb)524 static void last_sector_hacks(struct us_data *us, struct scsi_cmnd *srb)
525 {
526 	struct gendisk *disk;
527 	struct scsi_disk *sdkp;
528 	u32 sector;
529 
530 	/* To Report "Medium Error: Record Not Found */
531 	static unsigned char record_not_found[18] = {
532 		[0]	= 0x70,			/* current error */
533 		[2]	= MEDIUM_ERROR,		/* = 0x03 */
534 		[7]	= 0x0a,			/* additional length */
535 		[12]	= 0x14			/* Record Not Found */
536 	};
537 
538 	/*
539 	 * If last-sector problems can't occur, whether because the
540 	 * capacity was already decremented or because the device is
541 	 * known to report the correct capacity, then we don't need
542 	 * to do anything.
543 	 */
544 	if (!us->use_last_sector_hacks)
545 		return;
546 
547 	/* Was this command a READ(10) or a WRITE(10)? */
548 	if (srb->cmnd[0] != READ_10 && srb->cmnd[0] != WRITE_10)
549 		goto done;
550 
551 	/* Did this command access the last sector? */
552 	sector = (srb->cmnd[2] << 24) | (srb->cmnd[3] << 16) |
553 			(srb->cmnd[4] << 8) | (srb->cmnd[5]);
554 	disk = scsi_cmd_to_rq(srb)->q->disk;
555 	if (!disk)
556 		goto done;
557 	sdkp = scsi_disk(disk);
558 	if (!sdkp)
559 		goto done;
560 	if (sector + 1 != sdkp->capacity)
561 		goto done;
562 
563 	if (srb->result == SAM_STAT_GOOD && scsi_get_resid(srb) == 0) {
564 
565 		/*
566 		 * The command succeeded.  We know this device doesn't
567 		 * have the last-sector bug, so stop checking it.
568 		 */
569 		us->use_last_sector_hacks = 0;
570 
571 	} else {
572 		/*
573 		 * The command failed.  Allow up to 3 retries in case this
574 		 * is some normal sort of failure.  After that, assume the
575 		 * capacity is wrong and we're trying to access the sector
576 		 * beyond the end.  Replace the result code and sense data
577 		 * with values that will cause the SCSI core to fail the
578 		 * command immediately, instead of going into an infinite
579 		 * (or even just a very long) retry loop.
580 		 */
581 		if (++us->last_sector_retries < 3)
582 			return;
583 		srb->result = SAM_STAT_CHECK_CONDITION;
584 		memcpy(srb->sense_buffer, record_not_found,
585 				sizeof(record_not_found));
586 	}
587 
588  done:
589 	/*
590 	 * Don't reset the retry counter for TEST UNIT READY commands,
591 	 * because they get issued after device resets which might be
592 	 * caused by a failed last-sector access.
593 	 */
594 	if (srb->cmnd[0] != TEST_UNIT_READY)
595 		us->last_sector_retries = 0;
596 }
597 
598 /*
599  * Invoke the transport and basic error-handling/recovery methods
600  *
601  * This is used by the protocol layers to actually send the message to
602  * the device and receive the response.
603  */
usb_stor_invoke_transport(struct scsi_cmnd * srb,struct us_data * us)604 void usb_stor_invoke_transport(struct scsi_cmnd *srb, struct us_data *us)
605 {
606 	int need_auto_sense;
607 	int result;
608 
609 	/* send the command to the transport layer */
610 	scsi_set_resid(srb, 0);
611 	result = us->transport(srb, us);
612 
613 	/*
614 	 * if the command gets aborted by the higher layers, we need to
615 	 * short-circuit all other processing
616 	 */
617 	if (test_bit(US_FLIDX_TIMED_OUT, &us->dflags)) {
618 		usb_stor_dbg(us, "-- command was aborted\n");
619 		srb->result = DID_ABORT << 16;
620 		goto Handle_Errors;
621 	}
622 
623 	/* if there is a transport error, reset and don't auto-sense */
624 	if (result == USB_STOR_TRANSPORT_ERROR) {
625 		usb_stor_dbg(us, "-- transport indicates error, resetting\n");
626 		srb->result = DID_ERROR << 16;
627 		goto Handle_Errors;
628 	}
629 
630 	/* if the transport provided its own sense data, don't auto-sense */
631 	if (result == USB_STOR_TRANSPORT_NO_SENSE) {
632 		srb->result = SAM_STAT_CHECK_CONDITION;
633 		last_sector_hacks(us, srb);
634 		return;
635 	}
636 
637 	srb->result = SAM_STAT_GOOD;
638 
639 	/*
640 	 * Determine if we need to auto-sense
641 	 *
642 	 * I normally don't use a flag like this, but it's almost impossible
643 	 * to understand what's going on here if I don't.
644 	 */
645 	need_auto_sense = 0;
646 
647 	/*
648 	 * If we're running the CB transport, which is incapable
649 	 * of determining status on its own, we will auto-sense
650 	 * unless the operation involved a data-in transfer.  Devices
651 	 * can signal most data-in errors by stalling the bulk-in pipe.
652 	 */
653 	if ((us->protocol == USB_PR_CB || us->protocol == USB_PR_DPCM_USB) &&
654 			srb->sc_data_direction != DMA_FROM_DEVICE) {
655 		usb_stor_dbg(us, "-- CB transport device requiring auto-sense\n");
656 		need_auto_sense = 1;
657 	}
658 
659 	/* Some devices (Kindle) require another command after SYNC CACHE */
660 	if ((us->fflags & US_FL_SENSE_AFTER_SYNC) &&
661 			srb->cmnd[0] == SYNCHRONIZE_CACHE) {
662 		usb_stor_dbg(us, "-- sense after SYNC CACHE\n");
663 		need_auto_sense = 1;
664 	}
665 
666 	/*
667 	 * If we have a failure, we're going to do a REQUEST_SENSE
668 	 * automatically.  Note that we differentiate between a command
669 	 * "failure" and an "error" in the transport mechanism.
670 	 */
671 	if (result == USB_STOR_TRANSPORT_FAILED) {
672 		usb_stor_dbg(us, "-- transport indicates command failure\n");
673 		need_auto_sense = 1;
674 	}
675 
676 	/*
677 	 * Determine if this device is SAT by seeing if the
678 	 * command executed successfully.  Otherwise we'll have
679 	 * to wait for at least one CHECK_CONDITION to determine
680 	 * SANE_SENSE support
681 	 */
682 	if (unlikely((srb->cmnd[0] == ATA_16 || srb->cmnd[0] == ATA_12) &&
683 	    result == USB_STOR_TRANSPORT_GOOD &&
684 	    !(us->fflags & US_FL_SANE_SENSE) &&
685 	    !(us->fflags & US_FL_BAD_SENSE) &&
686 	    !(srb->cmnd[2] & 0x20))) {
687 		usb_stor_dbg(us, "-- SAT supported, increasing auto-sense\n");
688 		us->fflags |= US_FL_SANE_SENSE;
689 	}
690 
691 	/*
692 	 * A short transfer on a command where we don't expect it
693 	 * is unusual, but it doesn't mean we need to auto-sense.
694 	 */
695 	if ((scsi_get_resid(srb) > 0) &&
696 	    !((srb->cmnd[0] == REQUEST_SENSE) ||
697 	      (srb->cmnd[0] == INQUIRY) ||
698 	      (srb->cmnd[0] == MODE_SENSE) ||
699 	      (srb->cmnd[0] == LOG_SENSE) ||
700 	      (srb->cmnd[0] == MODE_SENSE_10))) {
701 		usb_stor_dbg(us, "-- unexpectedly short transfer\n");
702 	}
703 
704 	/* Now, if we need to do the auto-sense, let's do it */
705 	if (need_auto_sense) {
706 		int temp_result;
707 		struct scsi_eh_save ses;
708 		int sense_size = US_SENSE_SIZE;
709 		struct scsi_sense_hdr sshdr;
710 		const u8 *scdd;
711 		u8 fm_ili;
712 
713 		/* device supports and needs bigger sense buffer */
714 		if (us->fflags & US_FL_SANE_SENSE)
715 			sense_size = ~0;
716 Retry_Sense:
717 		usb_stor_dbg(us, "Issuing auto-REQUEST_SENSE\n");
718 
719 		scsi_eh_prep_cmnd(srb, &ses, NULL, 0, sense_size);
720 
721 		/* FIXME: we must do the protocol translation here */
722 		if (us->subclass == USB_SC_RBC || us->subclass == USB_SC_SCSI ||
723 				us->subclass == USB_SC_CYP_ATACB)
724 			srb->cmd_len = 6;
725 		else
726 			srb->cmd_len = 12;
727 
728 		/* issue the auto-sense command */
729 		scsi_set_resid(srb, 0);
730 		temp_result = us->transport(us->srb, us);
731 
732 		/* let's clean up right away */
733 		scsi_eh_restore_cmnd(srb, &ses);
734 
735 		if (test_bit(US_FLIDX_TIMED_OUT, &us->dflags)) {
736 			usb_stor_dbg(us, "-- auto-sense aborted\n");
737 			srb->result = DID_ABORT << 16;
738 
739 			/* If SANE_SENSE caused this problem, disable it */
740 			if (sense_size != US_SENSE_SIZE) {
741 				us->fflags &= ~US_FL_SANE_SENSE;
742 				us->fflags |= US_FL_BAD_SENSE;
743 			}
744 			goto Handle_Errors;
745 		}
746 
747 		/*
748 		 * Some devices claim to support larger sense but fail when
749 		 * trying to request it. When a transport failure happens
750 		 * using US_FS_SANE_SENSE, we always retry with a standard
751 		 * (small) sense request. This fixes some USB GSM modems
752 		 */
753 		if (temp_result == USB_STOR_TRANSPORT_FAILED &&
754 				sense_size != US_SENSE_SIZE) {
755 			usb_stor_dbg(us, "-- auto-sense failure, retry small sense\n");
756 			sense_size = US_SENSE_SIZE;
757 			us->fflags &= ~US_FL_SANE_SENSE;
758 			us->fflags |= US_FL_BAD_SENSE;
759 			goto Retry_Sense;
760 		}
761 
762 		/* Other failures */
763 		if (temp_result != USB_STOR_TRANSPORT_GOOD) {
764 			usb_stor_dbg(us, "-- auto-sense failure\n");
765 
766 			/*
767 			 * we skip the reset if this happens to be a
768 			 * multi-target device, since failure of an
769 			 * auto-sense is perfectly valid
770 			 */
771 			srb->result = DID_ERROR << 16;
772 			if (!(us->fflags & US_FL_SCM_MULT_TARG))
773 				goto Handle_Errors;
774 			return;
775 		}
776 
777 		/*
778 		 * If the sense data returned is larger than 18-bytes then we
779 		 * assume this device supports requesting more in the future.
780 		 * The response code must be 70h through 73h inclusive.
781 		 */
782 		if (srb->sense_buffer[7] > (US_SENSE_SIZE - 8) &&
783 		    !(us->fflags & US_FL_SANE_SENSE) &&
784 		    !(us->fflags & US_FL_BAD_SENSE) &&
785 		    (srb->sense_buffer[0] & 0x7C) == 0x70) {
786 			usb_stor_dbg(us, "-- SANE_SENSE support enabled\n");
787 			us->fflags |= US_FL_SANE_SENSE;
788 
789 			/*
790 			 * Indicate to the user that we truncated their sense
791 			 * because we didn't know it supported larger sense.
792 			 */
793 			usb_stor_dbg(us, "-- Sense data truncated to %i from %i\n",
794 				     US_SENSE_SIZE,
795 				     srb->sense_buffer[7] + 8);
796 			srb->sense_buffer[7] = (US_SENSE_SIZE - 8);
797 		}
798 
799 		scsi_normalize_sense(srb->sense_buffer, SCSI_SENSE_BUFFERSIZE,
800 				     &sshdr);
801 
802 		usb_stor_dbg(us, "-- Result from auto-sense is %d\n",
803 			     temp_result);
804 		usb_stor_dbg(us, "-- code: 0x%x, key: 0x%x, ASC: 0x%x, ASCQ: 0x%x\n",
805 			     sshdr.response_code, sshdr.sense_key,
806 			     sshdr.asc, sshdr.ascq);
807 #ifdef CONFIG_USB_STORAGE_DEBUG
808 		usb_stor_show_sense(us, sshdr.sense_key, sshdr.asc, sshdr.ascq);
809 #endif
810 
811 		/* set the result so the higher layers expect this data */
812 		srb->result = SAM_STAT_CHECK_CONDITION;
813 
814 		scdd = scsi_sense_desc_find(srb->sense_buffer,
815 					    SCSI_SENSE_BUFFERSIZE, 4);
816 		fm_ili = (scdd ? scdd[3] : srb->sense_buffer[2]) & 0xA0;
817 
818 		/*
819 		 * We often get empty sense data.  This could indicate that
820 		 * everything worked or that there was an unspecified
821 		 * problem.  We have to decide which.
822 		 */
823 		if (sshdr.sense_key == 0 && sshdr.asc == 0 && sshdr.ascq == 0 &&
824 		    fm_ili == 0) {
825 			/*
826 			 * If things are really okay, then let's show that.
827 			 * Zero out the sense buffer so the higher layers
828 			 * won't realize we did an unsolicited auto-sense.
829 			 */
830 			if (result == USB_STOR_TRANSPORT_GOOD) {
831 				srb->result = SAM_STAT_GOOD;
832 				srb->sense_buffer[0] = 0x0;
833 			}
834 
835 			/*
836 			 * ATA-passthru commands use sense data to report
837 			 * the command completion status, and often devices
838 			 * return Check Condition status when nothing is
839 			 * wrong.
840 			 */
841 			else if (srb->cmnd[0] == ATA_16 ||
842 					srb->cmnd[0] == ATA_12) {
843 				/* leave the data alone */
844 			}
845 
846 			/*
847 			 * If there was a problem, report an unspecified
848 			 * hardware error to prevent the higher layers from
849 			 * entering an infinite retry loop.
850 			 */
851 			else {
852 				srb->result = DID_ERROR << 16;
853 				if ((sshdr.response_code & 0x72) == 0x72)
854 					srb->sense_buffer[1] = HARDWARE_ERROR;
855 				else
856 					srb->sense_buffer[2] = HARDWARE_ERROR;
857 			}
858 		}
859 	}
860 
861 	/*
862 	 * Some devices don't work or return incorrect data the first
863 	 * time they get a READ(10) command, or for the first READ(10)
864 	 * after a media change.  If the INITIAL_READ10 flag is set,
865 	 * keep track of whether READ(10) commands succeed.  If the
866 	 * previous one succeeded and this one failed, set the REDO_READ10
867 	 * flag to force a retry.
868 	 */
869 	if (unlikely((us->fflags & US_FL_INITIAL_READ10) &&
870 			srb->cmnd[0] == READ_10)) {
871 		if (srb->result == SAM_STAT_GOOD) {
872 			set_bit(US_FLIDX_READ10_WORKED, &us->dflags);
873 		} else if (test_bit(US_FLIDX_READ10_WORKED, &us->dflags)) {
874 			clear_bit(US_FLIDX_READ10_WORKED, &us->dflags);
875 			set_bit(US_FLIDX_REDO_READ10, &us->dflags);
876 		}
877 
878 		/*
879 		 * Next, if the REDO_READ10 flag is set, return a result
880 		 * code that will cause the SCSI core to retry the READ(10)
881 		 * command immediately.
882 		 */
883 		if (test_bit(US_FLIDX_REDO_READ10, &us->dflags)) {
884 			clear_bit(US_FLIDX_REDO_READ10, &us->dflags);
885 			srb->result = DID_IMM_RETRY << 16;
886 			srb->sense_buffer[0] = 0;
887 		}
888 	}
889 
890 	/* Did we transfer less than the minimum amount required? */
891 	if ((srb->result == SAM_STAT_GOOD || srb->sense_buffer[2] == 0) &&
892 			scsi_bufflen(srb) - scsi_get_resid(srb) < srb->underflow)
893 		srb->result = DID_ERROR << 16;
894 
895 	last_sector_hacks(us, srb);
896 	return;
897 
898 	/*
899 	 * Error and abort processing: try to resynchronize with the device
900 	 * by issuing a port reset.  If that fails, try a class-specific
901 	 * device reset.
902 	 */
903   Handle_Errors:
904 
905 	/*
906 	 * Set the RESETTING bit, and clear the ABORTING bit so that
907 	 * the reset may proceed.
908 	 */
909 	scsi_lock(us_to_host(us));
910 	set_bit(US_FLIDX_RESETTING, &us->dflags);
911 	clear_bit(US_FLIDX_ABORTING, &us->dflags);
912 	scsi_unlock(us_to_host(us));
913 
914 	/*
915 	 * We must release the device lock because the pre_reset routine
916 	 * will want to acquire it.
917 	 */
918 	mutex_unlock(&us->dev_mutex);
919 	result = usb_stor_port_reset(us);
920 	mutex_lock(&us->dev_mutex);
921 
922 	if (result < 0) {
923 		scsi_lock(us_to_host(us));
924 		usb_stor_report_device_reset(us);
925 		scsi_unlock(us_to_host(us));
926 		us->transport_reset(us);
927 	}
928 	clear_bit(US_FLIDX_RESETTING, &us->dflags);
929 	last_sector_hacks(us, srb);
930 }
931 
932 /* Stop the current URB transfer */
usb_stor_stop_transport(struct us_data * us)933 void usb_stor_stop_transport(struct us_data *us)
934 {
935 	/*
936 	 * If the state machine is blocked waiting for an URB,
937 	 * let's wake it up.  The test_and_clear_bit() call
938 	 * guarantees that if a URB has just been submitted,
939 	 * it won't be cancelled more than once.
940 	 */
941 	if (test_and_clear_bit(US_FLIDX_URB_ACTIVE, &us->dflags)) {
942 		usb_stor_dbg(us, "-- cancelling URB\n");
943 		usb_unlink_urb(us->current_urb);
944 	}
945 
946 	/* If we are waiting for a scatter-gather operation, cancel it. */
947 	if (test_and_clear_bit(US_FLIDX_SG_ACTIVE, &us->dflags)) {
948 		usb_stor_dbg(us, "-- cancelling sg request\n");
949 		usb_sg_cancel(&us->current_sg);
950 	}
951 }
952 
953 /*
954  * Control/Bulk and Control/Bulk/Interrupt transport
955  */
956 
usb_stor_CB_transport(struct scsi_cmnd * srb,struct us_data * us)957 int usb_stor_CB_transport(struct scsi_cmnd *srb, struct us_data *us)
958 {
959 	unsigned int transfer_length = scsi_bufflen(srb);
960 	unsigned int pipe = 0;
961 	int result;
962 
963 	/* COMMAND STAGE */
964 	/* let's send the command via the control pipe */
965 	/*
966 	 * Command is sometime (f.e. after scsi_eh_prep_cmnd) on the stack.
967 	 * Stack may be vmallocated.  So no DMA for us.  Make a copy.
968 	 */
969 	memcpy(us->iobuf, srb->cmnd, srb->cmd_len);
970 	result = usb_stor_ctrl_transfer(us, us->send_ctrl_pipe,
971 				      US_CBI_ADSC,
972 				      USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0,
973 				      us->ifnum, us->iobuf, srb->cmd_len);
974 
975 	/* check the return code for the command */
976 	usb_stor_dbg(us, "Call to usb_stor_ctrl_transfer() returned %d\n",
977 		     result);
978 
979 	/* if we stalled the command, it means command failed */
980 	if (result == USB_STOR_XFER_STALLED) {
981 		return USB_STOR_TRANSPORT_FAILED;
982 	}
983 
984 	/* Uh oh... serious problem here */
985 	if (result != USB_STOR_XFER_GOOD) {
986 		return USB_STOR_TRANSPORT_ERROR;
987 	}
988 
989 	/* DATA STAGE */
990 	/* transfer the data payload for this command, if one exists*/
991 	if (transfer_length) {
992 		pipe = srb->sc_data_direction == DMA_FROM_DEVICE ?
993 				us->recv_bulk_pipe : us->send_bulk_pipe;
994 		result = usb_stor_bulk_srb(us, pipe, srb);
995 		usb_stor_dbg(us, "CBI data stage result is 0x%x\n", result);
996 
997 		/* if we stalled the data transfer it means command failed */
998 		if (result == USB_STOR_XFER_STALLED)
999 			return USB_STOR_TRANSPORT_FAILED;
1000 		if (result > USB_STOR_XFER_STALLED)
1001 			return USB_STOR_TRANSPORT_ERROR;
1002 	}
1003 
1004 	/* STATUS STAGE */
1005 
1006 	/*
1007 	 * NOTE: CB does not have a status stage.  Silly, I know.  So
1008 	 * we have to catch this at a higher level.
1009 	 */
1010 	if (us->protocol != USB_PR_CBI)
1011 		return USB_STOR_TRANSPORT_GOOD;
1012 
1013 	result = usb_stor_intr_transfer(us, us->iobuf, 2);
1014 	usb_stor_dbg(us, "Got interrupt data (0x%x, 0x%x)\n",
1015 		     us->iobuf[0], us->iobuf[1]);
1016 	if (result != USB_STOR_XFER_GOOD)
1017 		return USB_STOR_TRANSPORT_ERROR;
1018 
1019 	/*
1020 	 * UFI gives us ASC and ASCQ, like a request sense
1021 	 *
1022 	 * REQUEST_SENSE and INQUIRY don't affect the sense data on UFI
1023 	 * devices, so we ignore the information for those commands.  Note
1024 	 * that this means we could be ignoring a real error on these
1025 	 * commands, but that can't be helped.
1026 	 */
1027 	if (us->subclass == USB_SC_UFI) {
1028 		if (srb->cmnd[0] == REQUEST_SENSE ||
1029 		    srb->cmnd[0] == INQUIRY)
1030 			return USB_STOR_TRANSPORT_GOOD;
1031 		if (us->iobuf[0])
1032 			goto Failed;
1033 		return USB_STOR_TRANSPORT_GOOD;
1034 	}
1035 
1036 	/*
1037 	 * If not UFI, we interpret the data as a result code
1038 	 * The first byte should always be a 0x0.
1039 	 *
1040 	 * Some bogus devices don't follow that rule.  They stuff the ASC
1041 	 * into the first byte -- so if it's non-zero, call it a failure.
1042 	 */
1043 	if (us->iobuf[0]) {
1044 		usb_stor_dbg(us, "CBI IRQ data showed reserved bType 0x%x\n",
1045 			     us->iobuf[0]);
1046 		goto Failed;
1047 
1048 	}
1049 
1050 	/* The second byte & 0x0F should be 0x0 for good, otherwise error */
1051 	switch (us->iobuf[1] & 0x0F) {
1052 		case 0x00:
1053 			return USB_STOR_TRANSPORT_GOOD;
1054 		case 0x01:
1055 			goto Failed;
1056 	}
1057 	return USB_STOR_TRANSPORT_ERROR;
1058 
1059 	/*
1060 	 * the CBI spec requires that the bulk pipe must be cleared
1061 	 * following any data-in/out command failure (section 2.4.3.1.3)
1062 	 */
1063   Failed:
1064 	if (pipe)
1065 		usb_stor_clear_halt(us, pipe);
1066 	return USB_STOR_TRANSPORT_FAILED;
1067 }
1068 EXPORT_SYMBOL_GPL(usb_stor_CB_transport);
1069 
1070 /*
1071  * Bulk only transport
1072  */
1073 
1074 /* Determine what the maximum LUN supported is */
usb_stor_Bulk_max_lun(struct us_data * us)1075 int usb_stor_Bulk_max_lun(struct us_data *us)
1076 {
1077 	int result;
1078 
1079 	/* issue the command */
1080 	us->iobuf[0] = 0;
1081 	result = usb_stor_control_msg(us, us->recv_ctrl_pipe,
1082 				 US_BULK_GET_MAX_LUN,
1083 				 USB_DIR_IN | USB_TYPE_CLASS |
1084 				 USB_RECIP_INTERFACE,
1085 				 0, us->ifnum, us->iobuf, 1, 10*HZ);
1086 
1087 	usb_stor_dbg(us, "GetMaxLUN command result is %d, data is %d\n",
1088 		     result, us->iobuf[0]);
1089 
1090 	/*
1091 	 * If we have a successful request, return the result if valid. The
1092 	 * CBW LUN field is 4 bits wide, so the value reported by the device
1093 	 * should fit into that.
1094 	 */
1095 	if (result > 0) {
1096 		if (us->iobuf[0] < 16) {
1097 			return us->iobuf[0];
1098 		} else {
1099 			dev_info(&us->pusb_intf->dev,
1100 				 "Max LUN %d is not valid, using 0 instead",
1101 				 us->iobuf[0]);
1102 		}
1103 	}
1104 
1105 	/*
1106 	 * Some devices don't like GetMaxLUN.  They may STALL the control
1107 	 * pipe, they may return a zero-length result, they may do nothing at
1108 	 * all and timeout, or they may fail in even more bizarrely creative
1109 	 * ways.  In these cases the best approach is to use the default
1110 	 * value: only one LUN.
1111 	 */
1112 	return 0;
1113 }
1114 
usb_stor_Bulk_transport(struct scsi_cmnd * srb,struct us_data * us)1115 int usb_stor_Bulk_transport(struct scsi_cmnd *srb, struct us_data *us)
1116 {
1117 	struct bulk_cb_wrap *bcb = (struct bulk_cb_wrap *) us->iobuf;
1118 	struct bulk_cs_wrap *bcs = (struct bulk_cs_wrap *) us->iobuf;
1119 	unsigned int transfer_length = scsi_bufflen(srb);
1120 	unsigned int residue;
1121 	int result;
1122 	int fake_sense = 0;
1123 	unsigned int cswlen;
1124 	unsigned int cbwlen = US_BULK_CB_WRAP_LEN;
1125 
1126 	/* Take care of BULK32 devices; set extra byte to 0 */
1127 	if (unlikely(us->fflags & US_FL_BULK32)) {
1128 		cbwlen = 32;
1129 		us->iobuf[31] = 0;
1130 	}
1131 
1132 	/* set up the command wrapper */
1133 	bcb->Signature = cpu_to_le32(US_BULK_CB_SIGN);
1134 	bcb->DataTransferLength = cpu_to_le32(transfer_length);
1135 	bcb->Flags = srb->sc_data_direction == DMA_FROM_DEVICE ?
1136 		US_BULK_FLAG_IN : 0;
1137 	bcb->Tag = ++us->tag;
1138 	bcb->Lun = srb->device->lun;
1139 	if (us->fflags & US_FL_SCM_MULT_TARG)
1140 		bcb->Lun |= srb->device->id << 4;
1141 	bcb->Length = srb->cmd_len;
1142 
1143 	/* copy the command payload */
1144 	memset(bcb->CDB, 0, sizeof(bcb->CDB));
1145 	memcpy(bcb->CDB, srb->cmnd, bcb->Length);
1146 
1147 	/* send it to out endpoint */
1148 	usb_stor_dbg(us, "Bulk Command S 0x%x T 0x%x L %d F %d Trg %d LUN %d CL %d\n",
1149 		     le32_to_cpu(bcb->Signature), bcb->Tag,
1150 		     le32_to_cpu(bcb->DataTransferLength), bcb->Flags,
1151 		     (bcb->Lun >> 4), (bcb->Lun & 0x0F),
1152 		     bcb->Length);
1153 	result = usb_stor_bulk_transfer_buf(us, us->send_bulk_pipe,
1154 				bcb, cbwlen, NULL);
1155 	usb_stor_dbg(us, "Bulk command transfer result=%d\n", result);
1156 	if (result != USB_STOR_XFER_GOOD)
1157 		return USB_STOR_TRANSPORT_ERROR;
1158 
1159 	/* DATA STAGE */
1160 	/* send/receive data payload, if there is any */
1161 
1162 	/*
1163 	 * Some USB-IDE converter chips need a 100us delay between the
1164 	 * command phase and the data phase.  Some devices need a little
1165 	 * more than that, probably because of clock rate inaccuracies.
1166 	 */
1167 	if (unlikely(us->fflags & US_FL_GO_SLOW))
1168 		usleep_range(125, 150);
1169 
1170 	if (transfer_length) {
1171 		unsigned int pipe = srb->sc_data_direction == DMA_FROM_DEVICE ?
1172 				us->recv_bulk_pipe : us->send_bulk_pipe;
1173 		result = usb_stor_bulk_srb(us, pipe, srb);
1174 		usb_stor_dbg(us, "Bulk data transfer result 0x%x\n", result);
1175 		if (result == USB_STOR_XFER_ERROR)
1176 			return USB_STOR_TRANSPORT_ERROR;
1177 
1178 		/*
1179 		 * If the device tried to send back more data than the
1180 		 * amount requested, the spec requires us to transfer
1181 		 * the CSW anyway.  Since there's no point retrying
1182 		 * the command, we'll return fake sense data indicating
1183 		 * Illegal Request, Invalid Field in CDB.
1184 		 */
1185 		if (result == USB_STOR_XFER_LONG)
1186 			fake_sense = 1;
1187 
1188 		/*
1189 		 * Sometimes a device will mistakenly skip the data phase
1190 		 * and go directly to the status phase without sending a
1191 		 * zero-length packet.  If we get a 13-byte response here,
1192 		 * check whether it really is a CSW.
1193 		 */
1194 		if (result == USB_STOR_XFER_SHORT &&
1195 				srb->sc_data_direction == DMA_FROM_DEVICE &&
1196 				transfer_length - scsi_get_resid(srb) ==
1197 					US_BULK_CS_WRAP_LEN) {
1198 			struct scatterlist *sg = NULL;
1199 			unsigned int offset = 0;
1200 
1201 			if (usb_stor_access_xfer_buf((unsigned char *) bcs,
1202 					US_BULK_CS_WRAP_LEN, srb, &sg,
1203 					&offset, FROM_XFER_BUF) ==
1204 						US_BULK_CS_WRAP_LEN &&
1205 					bcs->Signature ==
1206 						cpu_to_le32(US_BULK_CS_SIGN)) {
1207 				usb_stor_dbg(us, "Device skipped data phase\n");
1208 				scsi_set_resid(srb, transfer_length);
1209 				goto skipped_data_phase;
1210 			}
1211 		}
1212 	}
1213 
1214 	/*
1215 	 * See flow chart on pg 15 of the Bulk Only Transport spec for
1216 	 * an explanation of how this code works.
1217 	 */
1218 
1219 	/* get CSW for device status */
1220 	usb_stor_dbg(us, "Attempting to get CSW...\n");
1221 	result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
1222 				bcs, US_BULK_CS_WRAP_LEN, &cswlen);
1223 
1224 	/*
1225 	 * Some broken devices add unnecessary zero-length packets to the
1226 	 * end of their data transfers.  Such packets show up as 0-length
1227 	 * CSWs.  If we encounter such a thing, try to read the CSW again.
1228 	 */
1229 	if (result == USB_STOR_XFER_SHORT && cswlen == 0) {
1230 		usb_stor_dbg(us, "Received 0-length CSW; retrying...\n");
1231 		result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
1232 				bcs, US_BULK_CS_WRAP_LEN, &cswlen);
1233 	}
1234 
1235 	/* did the attempt to read the CSW fail? */
1236 	if (result == USB_STOR_XFER_STALLED) {
1237 
1238 		/* get the status again */
1239 		usb_stor_dbg(us, "Attempting to get CSW (2nd try)...\n");
1240 		result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
1241 				bcs, US_BULK_CS_WRAP_LEN, NULL);
1242 	}
1243 
1244 	/* if we still have a failure at this point, we're in trouble */
1245 	usb_stor_dbg(us, "Bulk status result = %d\n", result);
1246 	if (result != USB_STOR_XFER_GOOD)
1247 		return USB_STOR_TRANSPORT_ERROR;
1248 
1249  skipped_data_phase:
1250 	/* check bulk status */
1251 	residue = le32_to_cpu(bcs->Residue);
1252 	usb_stor_dbg(us, "Bulk Status S 0x%x T 0x%x R %u Stat 0x%x\n",
1253 		     le32_to_cpu(bcs->Signature), bcs->Tag,
1254 		     residue, bcs->Status);
1255 	if (!(bcs->Tag == us->tag || (us->fflags & US_FL_BULK_IGNORE_TAG)) ||
1256 		bcs->Status > US_BULK_STAT_PHASE) {
1257 		usb_stor_dbg(us, "Bulk logical error\n");
1258 		return USB_STOR_TRANSPORT_ERROR;
1259 	}
1260 
1261 	/*
1262 	 * Some broken devices report odd signatures, so we do not check them
1263 	 * for validity against the spec. We store the first one we see,
1264 	 * and check subsequent transfers for validity against this signature.
1265 	 */
1266 	if (!us->bcs_signature) {
1267 		us->bcs_signature = bcs->Signature;
1268 		if (us->bcs_signature != cpu_to_le32(US_BULK_CS_SIGN))
1269 			usb_stor_dbg(us, "Learnt BCS signature 0x%08X\n",
1270 				     le32_to_cpu(us->bcs_signature));
1271 	} else if (bcs->Signature != us->bcs_signature) {
1272 		usb_stor_dbg(us, "Signature mismatch: got %08X, expecting %08X\n",
1273 			     le32_to_cpu(bcs->Signature),
1274 			     le32_to_cpu(us->bcs_signature));
1275 		return USB_STOR_TRANSPORT_ERROR;
1276 	}
1277 
1278 	/*
1279 	 * try to compute the actual residue, based on how much data
1280 	 * was really transferred and what the device tells us
1281 	 */
1282 	if (residue && !(us->fflags & US_FL_IGNORE_RESIDUE)) {
1283 
1284 		/*
1285 		 * Heuristically detect devices that generate bogus residues
1286 		 * by seeing what happens with INQUIRY and READ CAPACITY
1287 		 * commands.
1288 		 */
1289 		if (bcs->Status == US_BULK_STAT_OK &&
1290 				scsi_get_resid(srb) == 0 &&
1291 					((srb->cmnd[0] == INQUIRY &&
1292 						transfer_length == 36) ||
1293 					(srb->cmnd[0] == READ_CAPACITY &&
1294 						transfer_length == 8))) {
1295 			us->fflags |= US_FL_IGNORE_RESIDUE;
1296 
1297 		} else {
1298 			residue = min(residue, transfer_length);
1299 			scsi_set_resid(srb, max(scsi_get_resid(srb), residue));
1300 		}
1301 	}
1302 
1303 	/* based on the status code, we report good or bad */
1304 	switch (bcs->Status) {
1305 		case US_BULK_STAT_OK:
1306 			/* device babbled -- return fake sense data */
1307 			if (fake_sense) {
1308 				memcpy(srb->sense_buffer,
1309 				       usb_stor_sense_invalidCDB,
1310 				       sizeof(usb_stor_sense_invalidCDB));
1311 				return USB_STOR_TRANSPORT_NO_SENSE;
1312 			}
1313 
1314 			/* command good -- note that data could be short */
1315 			return USB_STOR_TRANSPORT_GOOD;
1316 
1317 		case US_BULK_STAT_FAIL:
1318 			/* command failed */
1319 			return USB_STOR_TRANSPORT_FAILED;
1320 
1321 		case US_BULK_STAT_PHASE:
1322 			/*
1323 			 * phase error -- note that a transport reset will be
1324 			 * invoked by the invoke_transport() function
1325 			 */
1326 			return USB_STOR_TRANSPORT_ERROR;
1327 	}
1328 
1329 	/* we should never get here, but if we do, we're in trouble */
1330 	return USB_STOR_TRANSPORT_ERROR;
1331 }
1332 EXPORT_SYMBOL_GPL(usb_stor_Bulk_transport);
1333 
1334 /***********************************************************************
1335  * Reset routines
1336  ***********************************************************************/
1337 
1338 /*
1339  * This is the common part of the device reset code.
1340  *
1341  * It's handy that every transport mechanism uses the control endpoint for
1342  * resets.
1343  *
1344  * Basically, we send a reset with a 5-second timeout, so we don't get
1345  * jammed attempting to do the reset.
1346  */
usb_stor_reset_common(struct us_data * us,u8 request,u8 requesttype,u16 value,u16 index,void * data,u16 size)1347 static int usb_stor_reset_common(struct us_data *us,
1348 		u8 request, u8 requesttype,
1349 		u16 value, u16 index, void *data, u16 size)
1350 {
1351 	int result;
1352 	int result2;
1353 
1354 	if (test_bit(US_FLIDX_DISCONNECTING, &us->dflags)) {
1355 		usb_stor_dbg(us, "No reset during disconnect\n");
1356 		return -EIO;
1357 	}
1358 
1359 	result = usb_stor_control_msg(us, us->send_ctrl_pipe,
1360 			request, requesttype, value, index, data, size,
1361 			5*HZ);
1362 	if (result < 0) {
1363 		usb_stor_dbg(us, "Soft reset failed: %d\n", result);
1364 		return result;
1365 	}
1366 
1367 	/*
1368 	 * Give the device some time to recover from the reset,
1369 	 * but don't delay disconnect processing.
1370 	 */
1371 	wait_event_interruptible_timeout(us->delay_wait,
1372 			test_bit(US_FLIDX_DISCONNECTING, &us->dflags),
1373 			HZ*6);
1374 	if (test_bit(US_FLIDX_DISCONNECTING, &us->dflags)) {
1375 		usb_stor_dbg(us, "Reset interrupted by disconnect\n");
1376 		return -EIO;
1377 	}
1378 
1379 	usb_stor_dbg(us, "Soft reset: clearing bulk-in endpoint halt\n");
1380 	result = usb_stor_clear_halt(us, us->recv_bulk_pipe);
1381 
1382 	usb_stor_dbg(us, "Soft reset: clearing bulk-out endpoint halt\n");
1383 	result2 = usb_stor_clear_halt(us, us->send_bulk_pipe);
1384 
1385 	/* return a result code based on the result of the clear-halts */
1386 	if (result >= 0)
1387 		result = result2;
1388 	if (result < 0)
1389 		usb_stor_dbg(us, "Soft reset failed\n");
1390 	else
1391 		usb_stor_dbg(us, "Soft reset done\n");
1392 	return result;
1393 }
1394 
1395 /* This issues a CB[I] Reset to the device in question */
1396 #define CB_RESET_CMD_SIZE	12
1397 
usb_stor_CB_reset(struct us_data * us)1398 int usb_stor_CB_reset(struct us_data *us)
1399 {
1400 	memset(us->iobuf, 0xFF, CB_RESET_CMD_SIZE);
1401 	us->iobuf[0] = SEND_DIAGNOSTIC;
1402 	us->iobuf[1] = 4;
1403 	return usb_stor_reset_common(us, US_CBI_ADSC,
1404 				 USB_TYPE_CLASS | USB_RECIP_INTERFACE,
1405 				 0, us->ifnum, us->iobuf, CB_RESET_CMD_SIZE);
1406 }
1407 EXPORT_SYMBOL_GPL(usb_stor_CB_reset);
1408 
1409 /*
1410  * This issues a Bulk-only Reset to the device in question, including
1411  * clearing the subsequent endpoint halts that may occur.
1412  */
usb_stor_Bulk_reset(struct us_data * us)1413 int usb_stor_Bulk_reset(struct us_data *us)
1414 {
1415 	return usb_stor_reset_common(us, US_BULK_RESET_REQUEST,
1416 				 USB_TYPE_CLASS | USB_RECIP_INTERFACE,
1417 				 0, us->ifnum, NULL, 0);
1418 }
1419 EXPORT_SYMBOL_GPL(usb_stor_Bulk_reset);
1420 
1421 /*
1422  * Issue a USB port reset to the device.  The caller must not hold
1423  * us->dev_mutex.
1424  */
usb_stor_port_reset(struct us_data * us)1425 int usb_stor_port_reset(struct us_data *us)
1426 {
1427 	int result;
1428 
1429 	/*for these devices we must use the class specific method */
1430 	if (us->pusb_dev->quirks & USB_QUIRK_RESET)
1431 		return -EPERM;
1432 
1433 	result = usb_lock_device_for_reset(us->pusb_dev, us->pusb_intf);
1434 	if (result < 0)
1435 		usb_stor_dbg(us, "unable to lock device for reset: %d\n",
1436 			     result);
1437 	else {
1438 		/* Were we disconnected while waiting for the lock? */
1439 		if (test_bit(US_FLIDX_DISCONNECTING, &us->dflags)) {
1440 			result = -EIO;
1441 			usb_stor_dbg(us, "No reset during disconnect\n");
1442 		} else {
1443 			result = usb_reset_device(us->pusb_dev);
1444 			usb_stor_dbg(us, "usb_reset_device returns %d\n",
1445 				     result);
1446 		}
1447 		usb_unlock_device(us->pusb_dev);
1448 	}
1449 	return result;
1450 }
1451