aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/usb/storage/usb.c
blob: 5ee7ac42e08f3bddb892109d07e99d6a216e2509 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
/* Driver for USB Mass Storage compliant devices
 *
 * Current development and maintenance by:
 *   (c) 1999-2003 Matthew Dharm (mdharm-usb@one-eyed-alien.net)
 *
 * Developed with the assistance of:
 *   (c) 2000 David L. Brown, Jr. (usb-storage@davidb.org)
 *   (c) 2003-2009 Alan Stern (stern@rowland.harvard.edu)
 *
 * Initial work by:
 *   (c) 1999 Michael Gee (michael@linuxspecific.com)
 *
 * usb_device_id support by Adam J. Richter (adam@yggdrasil.com):
 *   (c) 2000 Yggdrasil Computing, Inc.
 *
 * This driver is based on the 'USB Mass Storage Class' document. This
 * describes in detail the protocol used to communicate with such
 * devices.  Clearly, the designers had SCSI and ATAPI commands in
 * mind when they created this document.  The commands are all very
 * similar to commands in the SCSI-II and ATAPI specifications.
 *
 * It is important to note that in a number of cases this class
 * exhibits class-specific exemptions from the USB specification.
 * Notably the usage of NAK, STALL and ACK differs from the norm, in
 * that they are used to communicate wait, failed and OK on commands.
 *
 * Also, for certain devices, the interrupt endpoint is used to convey
 * status of a command.
 *
 * Please see http://www.one-eyed-alien.net/~mdharm/linux-usb for more
 * information about this driver.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2, or (at your option) any
 * later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#ifdef CONFIG_USB_STORAGE_DEBUG
#define DEBUG
#endif

#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/freezer.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/kthread.h>
#include <linux/mutex.h>
#include <linux/utsname.h>

#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>

#include "usb.h"
#include "scsiglue.h"
#include "transport.h"
#include "protocol.h"
#include "debug.h"
#include "initializers.h"

#include "sierra_ms.h"
#include "option_ms.h"

/* Some informational data */
MODULE_AUTHOR("Matthew Dharm <mdharm-usb@one-eyed-alien.net>");
MODULE_DESCRIPTION("USB Mass Storage driver for Linux");
MODULE_LICENSE("GPL");

static unsigned int delay_use = 1;
module_param(delay_use, uint, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(delay_use, "seconds to delay before using a new device");

static char quirks[128];
module_param_string(quirks, quirks, sizeof(quirks), S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(quirks, "supplemental list of device IDs and their quirks");


/*
 * The entries in this table correspond, line for line,
 * with the entries in usb_storage_usb_ids[], defined in usual-tables.c.
 */

/* The vendor name should be kept at eight characters or less, and
 * the product name should be kept at 16 characters or less. If a device
 * has the US_FL_FIX_INQUIRY flag, then the vendor and product names
 * normally generated by a device thorugh the INQUIRY response will be
 * taken from this list, and this is the reason for the above size
 * restriction. However, if the flag is not present, then you
 * are free to use as many characters as you like.
 */

#define UNUSUAL_DEV(idVendor, idProduct, bcdDeviceMin, bcdDeviceMax, \
		    vendor_name, product_name, use_protocol, use_transport, \
		    init_function, Flags) \
{ \
	.vendorName = vendor_name,	\
	.productName = product_name,	\
	.useProtocol = use_protocol,	\
	.useTransport = use_transport,	\
	.initFunction = init_function,	\
}

#define COMPLIANT_DEV	UNUSUAL_DEV

#define USUAL_DEV(use_protocol, use_transport, use_type) \
{ \
	.useProtocol = use_protocol,	\
	.useTransport = use_transport,	\
}

static struct us_unusual_dev us_unusual_dev_list[] = {
#	include "unusual_devs.h" 
	{ }		/* Terminating entry */
};

#undef UNUSUAL_DEV
#undef COMPLIANT_DEV
#undef USUAL_DEV


#ifdef CONFIG_PM	/* Minimal support for suspend and resume */

int usb_stor_suspend(struct usb_interface *iface, pm_message_t message)
{
	struct us_data *us = usb_get_intfdata(iface);

	/* Wait until no command is running */
	mutex_lock(&us->dev_mutex);

	US_DEBUGP("%s\n", __func__);
	if (us->suspend_resume_hook)
		(us->suspend_resume_hook)(us, US_SUSPEND);

	/* When runtime PM is working, we'll set a flag to indicate
	 * whether we should autoresume when a SCSI request arrives. */

	mutex_unlock(&us->dev_mutex);
	return 0;
}
EXPORT_SYMBOL_GPL(usb_stor_suspend);

int usb_stor_resume(struct usb_interface *iface)
{
	struct us_data *us = usb_get_intfdata(iface);

	mutex_lock(&us->dev_mutex);

	US_DEBUGP("%s\n", __func__);
	if (us->suspend_resume_hook)
		(us->suspend_resume_hook)(us, US_RESUME);

	mutex_unlock(&us->dev_mutex);
	return 0;
}
EXPORT_SYMBOL_GPL(usb_stor_resume);

int usb_stor_reset_resume(struct usb_interface *iface)
{
	struct us_data *us = usb_get_intfdata(iface);

	US_DEBUGP("%s\n", __func__);

	/* Report the reset to the SCSI core */
	usb_stor_report_bus_reset(us);

	/* FIXME: Notify the subdrivers that they need to reinitialize
	 * the device */
	return 0;
}
EXPORT_SYMBOL_GPL(usb_stor_reset_resume);

#endif /* CONFIG_PM */

/*
 * The next two routines get called just before and just after
 * a USB port reset, whether from this driver or a different one.
 */

int usb_stor_pre_reset(struct usb_interface *iface)
{
	struct us_data *us = usb_get_intfdata(iface);

	US_DEBUGP("%s\n", __func__);

	/* Make sure no command runs during the reset */
	mutex_lock(&us->dev_mutex);
	return 0;
}
EXPORT_SYMBOL_GPL(usb_stor_pre_reset);

int usb_stor_post_reset(struct usb_interface *iface)
{
	struct us_data *us = usb_get_intfdata(iface);

	US_DEBUGP("%s\n", __func__);

	/* Report the reset to the SCSI core */
	usb_stor_report_bus_reset(us);

	/* FIXME: Notify the subdrivers that they need to reinitialize
	 * the device */

	mutex_unlock(&us->dev_mutex);
	return 0;
}
EXPORT_SYMBOL_GPL(usb_stor_post_reset);

/*
 * fill_inquiry_response takes an unsigned char array (which must
 * be at least 36 characters) and populates the vendor name,
 * product name, and revision fields. Then the array is copied
 * into the SCSI command's response buffer (oddly enough
 * called request_buffer). data_len contains the length of the
 * data array, which again must be at least 36.
 */

void fill_inquiry_response(struct us_data *us, unsigned char *data,
		unsigned int data_len)
{
	if (data_len<36) // You lose.
		return;

	memset(data+8, ' ', 28);
	if(data[0]&0x20) { /* USB device currently not connected. Return
			      peripheral qualifier 001b ("...however, the
			      physical device is not currently connected
			      to this logical unit") and leave vendor and
			      product identification empty. ("If the target
			      does store some of the INQUIRY data on the
			      device, it may return zeros or ASCII spaces 
			      (20h) in those fields until the data is
			      available from the device."). */
	} else {
		u16 bcdDevice = le16_to_cpu(us->pusb_dev->descriptor.bcdDevice);
		int n;

		n = strlen(us->unusual_dev->vendorName);
		memcpy(data+8, us->unusual_dev->vendorName, min(8, n));
		n = strlen(us->unusual_dev->productName);
		memcpy(data+16, us->unusual_dev->productName, min(16, n));

		data[32] = 0x30 + ((bcdDevice>>12) & 0x0F);
		data[33] = 0x30 + ((bcdDevice>>8) & 0x0F);
		data[34] = 0x30 + ((bcdDevice>>4) & 0x0F);
		data[35] = 0x30 + ((bcdDevice) & 0x0F);
	}

	usb_stor_set_xfer_buf(data, data_len, us->srb);
}
EXPORT_SYMBOL_GPL(fill_inquiry_response);

static int usb_stor_control_thread(void * __us)
{
	struct us_data *us = (struct us_data *)__us;
	struct Scsi_Host *host = us_to_host(us);

	for(;;) {
		US_DEBUGP("*** thread sleeping.\n");
		if (wait_for_completion_interruptible(&us->cmnd_ready))
			break;

		US_DEBUGP("*** thread awakened.\n");

		/* lock the device pointers */
		mutex_lock(&(us->dev_mutex));

		/* lock access to the state */
		scsi_lock(host);

		/* When we are called with no command pending, we're done */
		if (us->srb == NULL) {
			scsi_unlock(host);
			mutex_unlock(&us->dev_mutex);
			US_DEBUGP("-- exiting\n");
			break;
		}

		/* has the command timed out *already* ? */
		if (test_bit(US_FLIDX_TIMED_OUT, &us->dflags)) {
			us->srb->result = DID_ABORT << 16;
			goto SkipForAbort;
		}

		scsi_unlock(host);

		/* reject the command if the direction indicator 
		 * is UNKNOWN
		 */
		if (us->srb->sc_data_direction == DMA_BIDIRECTIONAL) {
			US_DEBUGP("UNKNOWN data direction\n");
			us->srb->result = DID_ERROR << 16;
		}

		/* reject if target != 0 or if LUN is higher than
		 * the maximum known LUN
		 */
		else if (us->srb->device->id && 
				!(us->fflags & US_FL_SCM_MULT_TARG)) {
			US_DEBUGP("Bad target number (%d:%d)\n",
				  us->srb->device->id, us->srb->device->lun);
			us->srb->result = DID_BAD_TARGET << 16;
		}

		else if (us->srb->device->lun > us->max_lun) {
			US_DEBUGP("Bad LUN (%d:%d)\n",
				  us->srb->device->id, us->srb->device->lun);
			us->srb->result = DID_BAD_TARGET << 16;
		}

		/* Handle those devices which need us to fake 
		 * their inquiry data */
		else if ((us->srb->cmnd[0] == INQUIRY) &&
			    (us->fflags & US_FL_FIX_INQUIRY)) {
			unsigned char data_ptr[36] = {
			    0x00, 0x80, 0x02, 0x02,
			    0x1F, 0x00, 0x00, 0x00};

			US_DEBUGP("Faking INQUIRY command\n");
			fill_inquiry_response(us, data_ptr, 36);
			us->srb->result = SAM_STAT_GOOD;
		}

		/* we've got a command, let's do it! */
		else {
			US_DEBUG(usb_stor_show_command(us->srb));
			us->proto_handler(us->srb, us);
			usb_mark_last_busy(us->pusb_dev);
		}

		/* lock access to the state */
		scsi_lock(host);

		/* indicate that the command is done */
		if (us->srb->result != DID_ABORT << 16) {
			US_DEBUGP("scsi cmd done, result=0x%x\n", 
				   us->srb->result);
			us->srb->scsi_done(us->srb);
		} else {
SkipForAbort:
			US_DEBUGP("scsi command aborted\n");
		}

		/* If an abort request was received we need to signal that
		 * the abort has finished.  The proper test for this is
		 * the TIMED_OUT flag, not srb->result == DID_ABORT, because
		 * the timeout might have occurred after the command had
		 * already completed with a different result code. */
		if (test_bit(US_FLIDX_TIMED_OUT, &us->dflags)) {
			complete(&(us->notify));

			/* Allow USB transfers to resume */
			clear_bit(US_FLIDX_ABORTING, &us->dflags);
			clear_bit(US_FLIDX_TIMED_OUT, &us->dflags);
		}

		/* finished working on this command */
		us->srb = NULL;
		scsi_unlock(host);

		/* unlock the device pointers */
		mutex_unlock(&us->dev_mutex);
	} /* for (;;) */

	/* Wait until we are told to stop */
	for (;;) {
		set_current_state(TASK_INTERRUPTIBLE);
		if (kthread_should_stop())
			break;
		schedule();
	}
	__set_current_state(TASK_RUNNING);
	return 0;
}	

/***********************************************************************
 * Device probing and disconnecting
 ***********************************************************************/

/* Associate our private data with the USB device */
static int associate_dev(struct us_data *us, struct usb_interface *intf)
{
	US_DEBUGP("-- %s\n", __func__);

	/* Fill in the device-related fields */
	us->pusb_dev = interface_to_usbdev(intf);
	us->pusb_intf = intf;
	us->ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
	US_DEBUGP("Vendor: 0x%04x, Product: 0x%04x, Revision: 0x%04x\n",
			le16_to_cpu(us->pusb_dev->descriptor.idVendor),
			le16_to_cpu(us->pusb_dev->descriptor.idProduct),
			le16_to_cpu(us->pusb_dev->descriptor.bcdDevice));
	US_DEBUGP("Interface Subclass: 0x%02x, Protocol: 0x%02x\n",
			intf->cur_altsetting->desc.bInterfaceSubClass,
			intf->cur_altsetting->desc.bInterfaceProtocol);

	/* Store our private data in the interface */
	usb_set_intfdata(intf, us);

	/* Allocate the control/setup and DMA-mapped buffers */
	us->cr = kmalloc(sizeof(*us->cr), GFP_KERNEL);
	if (!us->cr) {
		US_DEBUGP("usb_ctrlrequest allocation failed\n");
		return -ENOMEM;
	}

	us->iobuf = usb_alloc_coherent(us->pusb_dev, US_IOBUF_SIZE,
			GFP_KERNEL, &us->iobuf_dma);
	if (!us->iobuf) {
		US_DEBUGP("I/O buffer allocation failed\n");
		return -ENOMEM;
	}
	return 0;
}

/* Works only for digits and letters, but small and fast */
#define TOLOWER(x) ((x) | 0x20)

/* Adjust device flags based on the "quirks=" module parameter */
static void adjust_quirks(struct us_data *us)
{
	char *p;
	u16 vid = le16_to_cpu(us->pusb_dev->descriptor.idVendor);
	u16 pid = le16_to_cpu(us->pusb_dev->descriptor.idProduct);
	unsigned f = 0;
	unsigned int mask = (US_FL_SANE_SENSE | US_FL_BAD_SENSE |
			US_FL_FIX_CAPACITY |
			US_FL_CAPACITY_HEURISTICS | US_FL_IGNORE_DEVICE |
			US_FL_NOT_LOCKABLE | US_FL_MAX_SECTORS_64 |
			US_FL_CAPACITY_OK | US_FL_IGNORE_RESIDUE |
			US_FL_SINGLE_LUN | US_FL_NO_WP_DETECT |
			US_FL_NO_READ_DISC_INFO | US_FL_NO_READ_CAPACITY_16);

	p = quirks;
	while (*p) {
		/* Each entry consists of VID:PID:flags */
		if (vid == simple_strtoul(p, &p, 16) &&
				*p == ':' &&
				pid == simple_strtoul(p+1, &p, 16) &&
				*p == ':')
			break;

		/* Move forward to the next entry */
		while (*p) {
			if (*p++ == ',')
				break;
		}
	}
	if (!*p)	/* No match */
		return;

	/* Collect the flags */
	while (*++p && *p != ',') {
		switch (TOLOWER(*p)) {
		case 'a':
			f |= US_FL_SANE_SENSE;
			break;
		case 'b':
			f |= US_FL_BAD_SENSE;
			break;
		case 'c':
			f |= US_FL_FIX_CAPACITY;
			break;
		case 'd':
			f |= US_FL_NO_READ_DISC_INFO;
			break;
		case 'e':
			f |= US_FL_NO_READ_CAPACITY_16;
			break;
		case 'h':
			f |= US_FL_CAPACITY_HEURISTICS;
			break;
		case 'i':
			f |= US_FL_IGNORE_DEVICE;
			break;
		case 'l':
			f |= US_FL_NOT_LOCKABLE;
			break;
		case 'm':
			f |= US_FL_MAX_SECTORS_64;
			break;
		case 'o':
			f |= US_FL_CAPACITY_OK;
			break;
		case 'r':
			f |= US_FL_IGNORE_RESIDUE;
			break;
		case 's':
			f |= US_FL_SINGLE_LUN;
			break;
		case 'w':
			f |= US_FL_NO_WP_DETECT;
			break;
		/* Ignore unrecognized flag characters */
		}
	}
	us->fflags = (us->fflags & ~mask) | f;
}

/* Get the unusual_devs entries and the string descriptors */
static int get_device_info(struct us_data *us, const struct usb_device_id *id,
		struct us_unusual_dev *unusual_dev)
{
	struct usb_device *dev = us->pusb_dev;
	struct usb_interface_descriptor *idesc =
		&us->pusb_intf->cur_altsetting->desc;
	struct device *pdev = &us->pusb_intf->dev;

	/* Store the entries */
	us->unusual_dev = unusual_dev;
	us->subclass = (unusual_dev->useProtocol == USB_SC_DEVICE) ?
			idesc->bInterfaceSubClass :
			unusual_dev->useProtocol;
	us->protocol = (unusual_dev->useTransport == USB_PR_DEVICE) ?
			idesc->bInterfaceProtocol :
			unusual_dev->useTransport;
	us->fflags = USB_US_ORIG_FLAGS(id->driver_info);
	adjust_quirks(us);

	if (us->fflags & US_FL_IGNORE_DEVICE) {
		dev_info(pdev, "device ignored\n");
		return -ENODEV;
	}

	/*
	 * This flag is only needed when we're in high-speed, so let's
	 * disable it if we're in full-speed
	 */
	if (dev->speed != USB_SPEED_HIGH)
		us->fflags &= ~US_FL_GO_SLOW;

	if (us->fflags)
		dev_info(pdev, "Quirks match for vid %04x pid %04x: %lx\n",
				le16_to_cpu(dev->descriptor.idVendor),
				le16_to_cpu(dev->descriptor.idProduct),
				us->fflags);

	/* Log a message if a non-generic unusual_dev entry contains an
	 * unnecessary subclass or protocol override.  This may stimulate
	 * reports from users that will help us remove unneeded entries
	 * from the unusual_devs.h table.
	 */
	if (id->idVendor || id->idProduct) {
		static const char *msgs[3] = {
			"an unneeded SubClass entry",
			"an unneeded Protocol entry",
			"unneeded SubClass and Protocol entries"};
		struct usb_device_descriptor *ddesc = &dev->descriptor;
		int msg = -1;

		if (unusual_dev->useProtocol != USB_SC_DEVICE &&
			us->subclass == idesc->bInterfaceSubClass)
			msg += 1;
		if (unusual_dev->useTransport != USB_PR_DEVICE &&
			us->protocol == idesc->bInterfaceProtocol)
			msg += 2;
		if (msg >= 0 && !(us->fflags & US_FL_NEED_OVERRIDE))
			dev_notice(pdev, "This device "
					"(%04x,%04x,%04x S %02x P %02x)"
					" has %s in unusual_devs.h (kernel"
					" %s)\n"
					"   Please send a copy of this message to "
					"<linux-usb@vger.kernel.org> and "
					"<usb-storage@lists.one-eyed-alien.net>\n",
					le16_to_cpu(ddesc->idVendor),
					le16_to_cpu(ddesc->idProduct),
					le16_to_cpu(ddesc->bcdDevice),
					idesc->bInterfaceSubClass,
					idesc->bInterfaceProtocol,
					msgs[msg],
					utsname()->release);
	}

	return 0;
}

/* Get the transport settings */
static void get_transport(struct us_data *us)
{
	switch (us->protocol) {
	case USB_PR_CB:
		us->transport_name = "Control/Bulk";
		us->transport = usb_stor_CB_transport;
		us->transport_reset = usb_stor_CB_reset;
		us->max_lun = 7;
		break;

	case USB_PR_CBI:
		us->transport_name = "Control/Bulk/Interrupt";
		us->transport = usb_stor_CB_transport;
		us->transport_reset = usb_stor_CB_reset;
		us->max_lun = 7;
		break;

	case USB_PR_BULK:
		us->transport_name = "Bulk";
		us->transport = usb_stor_Bulk_transport;
		us->transport_reset = usb_stor_Bulk_reset;
		break;
	}
}

/* Get the protocol settings */
static void get_protocol(struct us_data *us)
{
	switch (us->subclass) {
	case USB_SC_RBC:
		us->protocol_name = "Reduced Block Commands (RBC)";
		us->proto_handler = usb_stor_transparent_scsi_command;
		break;

	case USB_SC_8020:
		us->protocol_name = "8020i";
		us->proto_handler = usb_stor_pad12_command;
		us->max_lun = 0;
		break;

	case USB_SC_QIC:
		us->protocol_name = "QIC-157";
		us->proto_handler = usb_stor_pad12_command;
		us->max_lun = 0;
		break;

	case USB_SC_8070:
		us->protocol_name = "8070i";
		us->proto_handler = usb_stor_pad12_command;
		us->max_lun = 0;
		break;

	case USB_SC_SCSI:
		us->protocol_name = "Transparent SCSI";
		us->proto_handler = usb_stor_transparent_scsi_command;
		break;

	case USB_SC_UFI:
		us->protocol_name = "Uniform Floppy Interface (UFI)";
		us->proto_handler = usb_stor_ufi_command;
		break;
	}
}

/* Get the pipe settings */
static int get_pipes(struct us_data *us)
{
	struct usb_host_interface *altsetting =
		us->pusb_intf->cur_altsetting;
	int i;
	struct usb_endpoint_descriptor *ep;
	struct usb_endpoint_descriptor *ep_in = NULL;
	struct usb_endpoint_descriptor *ep_out = NULL;
	struct usb_endpoint_descriptor *ep_int = NULL;

	/*
	 * Find the first endpoint of each type we need.
	 * We are expecting a minimum of 2 endpoints - in and out (bulk).
	 * An optional interrupt-in is OK (necessary for CBI protocol).
	 * We will ignore any others.
	 */
	for (i = 0; i < altsetting->desc.bNumEndpoints; i++) {
		ep = &altsetting->endpoint[i].desc;

		if (usb_endpoint_xfer_bulk(ep)) {
			if (usb_endpoint_dir_in(ep)) {
				if (!ep_in)
					ep_in = ep;
			} else {
				if (!ep_out)
					ep_out = ep;
			}
		}

		else if (usb_endpoint_is_int_in(ep)) {
			if (!ep_int)
				ep_int = ep;
		}
	}

	if (!ep_in || !ep_out || (us->protocol == USB_PR_CBI && !ep_int)) {
		US_DEBUGP("Endpoint sanity check failed! Rejecting dev.\n");
		return -EIO;
	}

	/* Calculate and store the pipe values */
	us->send_ctrl_pipe = usb_sndctrlpipe(us->pusb_dev, 0);
	us->recv_ctrl_pipe = usb_rcvctrlpipe(us->pusb_dev, 0);
	us->send_bulk_pipe = usb_sndbulkpipe(us->pusb_dev,
		usb_endpoint_num(ep_out));
	us->recv_bulk_pipe = usb_rcvbulkpipe(us->pusb_dev, 
		usb_endpoint_num(ep_in));
	if (ep_int) {
		us->recv_intr_pipe = usb_rcvintpipe(us->pusb_dev,
			usb_endpoint_num(ep_int));
		us->ep_bInterval = ep_int->bInterval;
	}
	return 0;
}

/* Initialize all the dynamic resources we need */
static int usb_stor_acquire_resources(struct us_data *us)
{
	int p;
	struct task_struct *th;

	us->current_urb = usb_alloc_urb(0, GFP_KERNEL);
	if (!us->current_urb) {
		US_DEBUGP("URB allocation failed\n");
		return -ENOMEM;
	}

	/* Just before we start our control thread, initialize
	 * the device if it needs initialization */
	if (us->unusual_dev->initFunction) {
		p = us->unusual_dev->initFunction(us);
		if (p)
			return p;
	}

	/* Start up our control thread */
	th = kthread_run(usb_stor_control_thread, us, "usb-storage");
	if (IS_ERR(th)) {
		dev_warn(&us->pusb_intf->dev,
				"Unable to start control thread\n");
		return PTR_ERR(th);
	}
	us->ctl_thread = th;

	return 0;
}

/* Release all our dynamic resources */
static void usb_stor_release_resources(struct us_data *us)
{
	US_DEBUGP("-- %s\n", __func__);

	/* Tell the control thread to exit.  The SCSI host must
	 * already have been removed and the DISCONNECTING flag set
	 * so that we won't accept any more commands.
	 */
	US_DEBUGP("-- sending exit command to thread\n");
	complete(&us->cmnd_ready);
	if (us->ctl_thread)
		kthread_stop(us->ctl_thread);

	/* Call the destructor routine, if it exists */
	if (us->extra_destructor) {
		US_DEBUGP("-- calling extra_destructor()\n");
		us->extra_destructor(us->extra);
	}

	/* Free the extra data and the URB */
	kfree(us->extra);
	usb_free_urb(us->current_urb);
}

/* Dissociate from the USB device */
static void dissociate_dev(struct us_data *us)
{
	US_DEBUGP("-- %s\n", __func__);

	/* Free the buffers */
	kfree(us->cr);
	usb_free_coherent(us->pusb_dev, US_IOBUF_SIZE, us->iobuf, us->iobuf_dma);

	/* Remove our private data from the interface */
	usb_set_intfdata(us->pusb_intf, NULL);
}

/* First stage of disconnect processing: stop SCSI scanning,
 * remove the host, and stop accepting new commands
 */
static void quiesce_and_remove_host(struct us_data *us)
{
	struct Scsi_Host *host = us_to_host(us);

	/* If the device is really gone, cut short reset delays */
	if (us->pusb_dev->state == USB_STATE_NOTATTACHED)
		set_bit(US_FLIDX_DISCONNECTING, &us->dflags);

	/* Prevent SCSI-scanning (if it hasn't started yet)
	 * and wait for the SCSI-scanning thread to stop.
	 */
	set_bit(US_FLIDX_DONT_SCAN, &us->dflags);
	wake_up(&us->delay_wait);
	wait_for_completion(&us->scanning_done);

	/* Removing the host will perform an orderly shutdown: caches
	 * synchronized, disks spun down, etc.
	 */
	scsi_remove_host(host);

	/* Prevent any new commands from being accepted and cut short
	 * reset delays.
	 */
	scsi_lock(host);
	set_bit(US_FLIDX_DISCONNECTING, &us->dflags);
	scsi_unlock(host);
	wake_up(&us->delay_wait);
}

/* Second stage of disconnect processing: deallocate all resources */
static void release_everything(struct us_data *us)
{
	usb_stor_release_resources(us);
	dissociate_dev(us);

	/* Drop our reference to the host; the SCSI core will free it
	 * (and "us" along with it) when the refcount becomes 0. */
	scsi_host_put(us_to_host(us));
}

/* Thread to carry out delayed SCSI-device scanning */
static int usb_stor_scan_thread(void * __us)
{
	struct us_data *us = (struct us_data *)__us;
	struct device *dev = &us->pusb_intf->dev;

	dev_dbg(dev, "device found\n");

	set_freezable();
	/* Wait for the timeout to expire or for a disconnect */
	if (delay_use > 0) {
		dev_dbg(dev, "waiting for device to settle "
				"before scanning\n");
		wait_event_freezable_timeout(us->delay_wait,
				test_bit(US_FLIDX_DONT_SCAN, &us->dflags),
				delay_use * HZ);
	}

	/* If the device is still connected, perform the scanning */
	if (!test_bit(US_FLIDX_DONT_SCAN, &us->dflags)) {

		/* For bulk-only devices, determine the max LUN value */
		if (us->protocol == USB_PR_BULK &&
				!(us->fflags & US_FL_SINGLE_LUN)) {
			mutex_lock(&us->dev_mutex);
			us->max_lun = usb_stor_Bulk_max_lun(us);
			mutex_unlock(&us->dev_mutex);
		}
		scsi_scan_host(us_to_host(us));
		dev_dbg(dev, "scan complete\n");

		/* Should we unbind if no devices were detected? */
	}

	usb_autopm_put_interface(us->pusb_intf);
	complete_and_exit(&us->scanning_done, 0);
}

static unsigned int usb_stor_sg_tablesize(struct usb_interface *intf)
{
	struct usb_device *usb_dev = interface_to_usbdev(intf);

	if (usb_dev->bus->sg_tablesize) {
		return usb_dev->bus->sg_tablesize;
	}
	return SG_ALL;
}

/* First part of general USB mass-storage probing */
int usb_stor_probe1(struct us_data **pus,
		struct usb_interface *intf,
		const struct usb_device_id *id,
		struct us_unusual_dev *unusual_dev)
{
	struct Scsi_Host *host;
	struct us_data *us;
	int result;

	US_DEBUGP("USB Mass Storage device detected\n");

	/*
	 * Ask the SCSI layer to allocate a host structure, with extra
	 * space at the end for our private us_data structure.
	 */
	host = scsi_host_alloc(&usb_stor_host_template, sizeof(*us));
	if (!host) {
		dev_warn(&intf->dev,
				"Unable to allocate the scsi host\n");
		return -ENOMEM;
	}

	/*
	 * Allow 16-byte CDBs and thus > 2TB
	 */
	host->max_cmd_len = 16;
	host->sg_tablesize = usb_stor_sg_tablesize(intf);
	*pus = us = host_to_us(host);
	memset(us, 0, sizeof(struct us_data));
	mutex_init(&(us->dev_mutex));
	init_completion(&us->cmnd_ready);
	init_completion(&(us->notify));
	init_waitqueue_head(&us->delay_wait);
	init_completion(&us->scanning_done);

	/* Associate the us_data structure with the USB device */
	result = associate_dev(us, intf);
	if (result)
		goto BadDevice;

	/* Get the unusual_devs entries and the descriptors */
	result = get_device_info(us, id, unusual_dev);
	if (result)
		goto BadDevice;

	/* Get standard transport and protocol settings */
	get_transport(us);
	get_protocol(us);

	/* Give the caller a chance to fill in specialized transport
	 * or protocol settings.
	 */
	return 0;

BadDevice:
	US_DEBUGP("storage_probe() failed\n");
	release_everything(us);
	return result;
}
EXPORT_SYMBOL_GPL(usb_stor_probe1);

/* Second part of general USB mass-storage probing */
int usb_stor_probe2(struct us_data *us)
{
	struct task_struct *th;
	int result;
	struct device *dev = &us->pusb_intf->dev;

	/* Make sure the transport and protocol have both been set */
	if (!us->transport || !us->proto_handler) {
		result = -ENXIO;
		goto BadDevice;
	}
	US_DEBUGP("Transport: %s\n", us->transport_name);
	US_DEBUGP("Protocol: %s\n", us->protocol_name);

	/* fix for single-lun devices */
	if (us->fflags & US_FL_SINGLE_LUN)
		us->max_lun = 0;

	/* Find the endpoints and calculate pipe values */
	result = get_pipes(us);
	if (result)
		goto BadDevice;

	/* Acquire all the other resources and add the host */
	result = usb_stor_acquire_resources(us);
	if (result)
		goto BadDevice;
	snprintf(us->scsi_name, sizeof(us->scsi_name), "usb-storage %s",
					dev_name(&us->pusb_intf->dev));
	result = scsi_add_host(us_to_host(us), dev);
	if (result) {
		dev_warn(dev,
				"Unable to add the scsi host\n");
		goto BadDevice;
	}

	/* Start up the thread for delayed SCSI-device scanning */
	th = kthread_create(usb_stor_scan_thread, us, "usb-stor-scan");
	if (IS_ERR(th)) {
		dev_warn(dev,
				"Unable to start the device-scanning thread\n");
		complete(&us->scanning_done);
		quiesce_and_remove_host(us);
		result = PTR_ERR(th);
		goto BadDevice;
	}

	usb_autopm_get_interface_no_resume(us->pusb_intf);
	wake_up_process(th);

	return 0;

	/* We come here if there are any problems */
BadDevice:
	US_DEBUGP("storage_probe() failed\n");
	release_everything(us);
	return result;
}
EXPORT_SYMBOL_GPL(usb_stor_probe2);

/* Handle a USB mass-storage disconnect */
void usb_stor_disconnect(struct usb_interface *intf)
{
	struct us_data *us = usb_get_intfdata(intf);

	US_DEBUGP("storage_disconnect() called\n");
	quiesce_and_remove_host(us);
	release_everything(us);
}
EXPORT_SYMBOL_GPL(usb_stor_disconnect);

/* The main probe routine for standard devices */
static int storage_probe(struct usb_interface *intf,
			 const struct usb_device_id *id)
{
	struct us_data *us;
	int result;

	/*
	 * If libusual is configured, let it decide whether a standard
	 * device should be handled by usb-storage or by ub.
	 * If the device isn't standard (is handled by a subdriver
	 * module) then don't accept it.
	 */
	if (usb_usual_check_type(id, USB_US_TYPE_STOR) ||
			usb_usual_ignore_device(intf))
		return -ENXIO;

	/*
	 * Call the general probe procedures.
	 *
	 * The unusual_dev_list array is parallel to the usb_storage_usb_ids
	 * table, so we use the index of the id entry to find the
	 * corresponding unusual_devs entry.
	 */
	result = usb_stor_probe1(&us, intf, id,
			(id - usb_storage_usb_ids) + us_unusual_dev_list);
	if (result)
		return result;

	/* No special transport or protocol settings in the main module */

	result = usb_stor_probe2(us);
	return result;
}

/***********************************************************************
 * Initialization and registration
 ***********************************************************************/

static struct usb_driver usb_storage_driver = {
	.name =		"usb-storage",
	.probe =	storage_probe,
	.disconnect =	usb_stor_disconnect,
	.suspend =	usb_stor_suspend,
	.resume =	usb_stor_resume,
	.reset_resume =	usb_stor_reset_resume,
	.pre_reset =	usb_stor_pre_reset,
	.post_reset =	usb_stor_post_reset,
	.id_table =	usb_storage_usb_ids,
	.supports_autosuspend = 1,
	.soft_unbind =	1,
};

static int __init usb_stor_init(void)
{
	int retval;

	pr_info("Initializing USB Mass Storage driver...\n");

	/* register the driver, return usb_register return code if error */
	retval = usb_register(&usb_storage_driver);
	if (retval == 0) {
		pr_info("USB Mass Storage support registered.\n");
		usb_usual_set_present(USB_US_TYPE_STOR);
	}
	return retval;
}

static void __exit usb_stor_exit(void)
{
	US_DEBUGP("usb_stor_exit() called\n");

	/* Deregister the driver
	 * This will cause disconnect() to be called for each
	 * attached unit
	 */
	US_DEBUGP("-- calling usb_deregister()\n");
	usb_deregister(&usb_storage_driver) ;

	usb_usual_clear_present(USB_US_TYPE_STOR);
}

module_init(usb_stor_init);
module_exit(usb_stor_exit);