summaryrefslogtreecommitdiff
path: root/drivers/usb/core/config.c
blob: 883549ee946cb5e206623bfc79d199620078a6bb (plain)
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
/*
 * Released under the GPLv2 only.
 * SPDX-License-Identifier: GPL-2.0
 */

#include <linux/usb.h>
#include <linux/usb/ch9.h>
#include <linux/usb/hcd.h>
#include <linux/usb/quirks.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/device.h>
#include <asm/byteorder.h>
#include "usb.h"


#define USB_MAXALTSETTING		128	/* Hard limit */

#define USB_MAXCONFIG			8	/* Arbitrary limit */


static inline const char *plural(int n)
{
	return (n == 1 ? "" : "s");
}

static int find_next_descriptor(unsigned char *buffer, int size,
    int dt1, int dt2, int *num_skipped)
{
	struct usb_descriptor_header *h;
	int n = 0;
	unsigned char *buffer0 = buffer;

	/* Find the next descriptor of type dt1 or dt2 */
	while (size > 0) {
		h = (struct usb_descriptor_header *) buffer;
		if (h->bDescriptorType == dt1 || h->bDescriptorType == dt2)
			break;
		buffer += h->bLength;
		size -= h->bLength;
		++n;
	}

	/* Store the number of descriptors skipped and return the
	 * number of bytes skipped */
	if (num_skipped)
		*num_skipped = n;
	return buffer - buffer0;
}

static void usb_parse_ssp_isoc_endpoint_companion(struct device *ddev,
		int cfgno, int inum, int asnum, struct usb_host_endpoint *ep,
		unsigned char *buffer, int size)
{
	struct usb_ssp_isoc_ep_comp_descriptor *desc;

	/*
	 * The SuperSpeedPlus Isoc endpoint companion descriptor immediately
	 * follows the SuperSpeed Endpoint Companion descriptor
	 */
	desc = (struct usb_ssp_isoc_ep_comp_descriptor *) buffer;
	if (desc->bDescriptorType != USB_DT_SSP_ISOC_ENDPOINT_COMP ||
	    size < USB_DT_SSP_ISOC_EP_COMP_SIZE) {
		dev_warn(ddev, "Invalid SuperSpeedPlus isoc endpoint companion"
			 "for config %d interface %d altsetting %d ep %d.\n",
			 cfgno, inum, asnum, ep->desc.bEndpointAddress);
		return;
	}
	memcpy(&ep->ssp_isoc_ep_comp, desc, USB_DT_SSP_ISOC_EP_COMP_SIZE);
}

static void usb_parse_ss_endpoint_companion(struct device *ddev, int cfgno,
		int inum, int asnum, struct usb_host_endpoint *ep,
		unsigned char *buffer, int size)
{
	struct usb_ss_ep_comp_descriptor *desc;
	int max_tx;

	/* The SuperSpeed endpoint companion descriptor is supposed to
	 * be the first thing immediately following the endpoint descriptor.
	 */
	desc = (struct usb_ss_ep_comp_descriptor *) buffer;

	if (desc->bDescriptorType != USB_DT_SS_ENDPOINT_COMP ||
			size < USB_DT_SS_EP_COMP_SIZE) {
		dev_warn(ddev, "No SuperSpeed endpoint companion for config %d "
				" interface %d altsetting %d ep %d: "
				"using minimum values\n",
				cfgno, inum, asnum, ep->desc.bEndpointAddress);

		/* Fill in some default values.
		 * Leave bmAttributes as zero, which will mean no streams for
		 * bulk, and isoc won't support multiple bursts of packets.
		 * With bursts of only one packet, and a Mult of 1, the max
		 * amount of data moved per endpoint service interval is one
		 * packet.
		 */
		ep->ss_ep_comp.bLength = USB_DT_SS_EP_COMP_SIZE;
		ep->ss_ep_comp.bDescriptorType = USB_DT_SS_ENDPOINT_COMP;
		if (usb_endpoint_xfer_isoc(&ep->desc) ||
				usb_endpoint_xfer_int(&ep->desc))
			ep->ss_ep_comp.wBytesPerInterval =
					ep->desc.wMaxPacketSize;
		return;
	}
	buffer += desc->bLength;
	size -= desc->bLength;
	memcpy(&ep->ss_ep_comp, desc, USB_DT_SS_EP_COMP_SIZE);

	/* Check the various values */
	if (usb_endpoint_xfer_control(&ep->desc) && desc->bMaxBurst != 0) {
		dev_warn(ddev, "Control endpoint with bMaxBurst = %d in "
				"config %d interface %d altsetting %d ep %d: "
				"setting to zero\n", desc->bMaxBurst,
				cfgno, inum, asnum, ep->desc.bEndpointAddress);
		ep->ss_ep_comp.bMaxBurst = 0;
	} else if (desc->bMaxBurst > 15) {
		dev_warn(ddev, "Endpoint with bMaxBurst = %d in "
				"config %d interface %d altsetting %d ep %d: "
				"setting to 15\n", desc->bMaxBurst,
				cfgno, inum, asnum, ep->desc.bEndpointAddress);
		ep->ss_ep_comp.bMaxBurst = 15;
	}

	if ((usb_endpoint_xfer_control(&ep->desc) ||
			usb_endpoint_xfer_int(&ep->desc)) &&
				desc->bmAttributes != 0) {
		dev_warn(ddev, "%s endpoint with bmAttributes = %d in "
				"config %d interface %d altsetting %d ep %d: "
				"setting to zero\n",
				usb_endpoint_xfer_control(&ep->desc) ? "Control" : "Bulk",
				desc->bmAttributes,
				cfgno, inum, asnum, ep->desc.bEndpointAddress);
		ep->ss_ep_comp.bmAttributes = 0;
	} else if (usb_endpoint_xfer_bulk(&ep->desc) &&
			desc->bmAttributes > 16) {
		dev_warn(ddev, "Bulk endpoint with more than 65536 streams in "
				"config %d interface %d altsetting %d ep %d: "
				"setting to max\n",
				cfgno, inum, asnum, ep->desc.bEndpointAddress);
		ep->ss_ep_comp.bmAttributes = 16;
	} else if (usb_endpoint_xfer_isoc(&ep->desc) &&
		   !USB_SS_SSP_ISOC_COMP(desc->bmAttributes) &&
		   USB_SS_MULT(desc->bmAttributes) > 3) {
		dev_warn(ddev, "Isoc endpoint has Mult of %d in "
				"config %d interface %d altsetting %d ep %d: "
				"setting to 3\n",
				USB_SS_MULT(desc->bmAttributes),
				cfgno, inum, asnum, ep->desc.bEndpointAddress);
		ep->ss_ep_comp.bmAttributes = 2;
	}

	if (usb_endpoint_xfer_isoc(&ep->desc))
		max_tx = (desc->bMaxBurst + 1) *
			(USB_SS_MULT(desc->bmAttributes)) *
			usb_endpoint_maxp(&ep->desc);
	else if (usb_endpoint_xfer_int(&ep->desc))
		max_tx = usb_endpoint_maxp(&ep->desc) *
			(desc->bMaxBurst + 1);
	else
		max_tx = 999999;
	if (le16_to_cpu(desc->wBytesPerInterval) > max_tx) {
		dev_warn(ddev, "%s endpoint with wBytesPerInterval of %d in "
				"config %d interface %d altsetting %d ep %d: "
				"setting to %d\n",
				usb_endpoint_xfer_isoc(&ep->desc) ? "Isoc" : "Int",
				le16_to_cpu(desc->wBytesPerInterval),
				cfgno, inum, asnum, ep->desc.bEndpointAddress,
				max_tx);
		ep->ss_ep_comp.wBytesPerInterval = cpu_to_le16(max_tx);
	}
	/* Parse a possible SuperSpeedPlus isoc ep companion descriptor */
	if (usb_endpoint_xfer_isoc(&ep->desc) &&
	    USB_SS_SSP_ISOC_COMP(desc->bmAttributes))
		usb_parse_ssp_isoc_endpoint_companion(ddev, cfgno, inum, asnum,
							ep, buffer, size);
}

static const unsigned short low_speed_maxpacket_maxes[4] = {
	[USB_ENDPOINT_XFER_CONTROL] = 8,
	[USB_ENDPOINT_XFER_ISOC] = 0,
	[USB_ENDPOINT_XFER_BULK] = 0,
	[USB_ENDPOINT_XFER_INT] = 8,
};
static const unsigned short full_speed_maxpacket_maxes[4] = {
	[USB_ENDPOINT_XFER_CONTROL] = 64,
	[USB_ENDPOINT_XFER_ISOC] = 1023,
	[USB_ENDPOINT_XFER_BULK] = 64,
	[USB_ENDPOINT_XFER_INT] = 64,
};
static const unsigned short high_speed_maxpacket_maxes[4] = {
	[USB_ENDPOINT_XFER_CONTROL] = 64,
	[USB_ENDPOINT_XFER_ISOC] = 1024,
	[USB_ENDPOINT_XFER_BULK] = 512,
	[USB_ENDPOINT_XFER_INT] = 1024,
};
static const unsigned short super_speed_maxpacket_maxes[4] = {
	[USB_ENDPOINT_XFER_CONTROL] = 512,
	[USB_ENDPOINT_XFER_ISOC] = 1024,
	[USB_ENDPOINT_XFER_BULK] = 1024,
	[USB_ENDPOINT_XFER_INT] = 1024,
};

static int usb_parse_endpoint(struct device *ddev, int cfgno, int inum,
    int asnum, struct usb_host_interface *ifp, int num_ep,
    unsigned char *buffer, int size)
{
	unsigned char *buffer0 = buffer;
	struct usb_endpoint_descriptor *d;
	struct usb_host_endpoint *endpoint;
	int n, i, j, retval;
	unsigned int maxp;
	const unsigned short *maxpacket_maxes;

	d = (struct usb_endpoint_descriptor *) buffer;
	buffer += d->bLength;
	size -= d->bLength;

	if (d->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE)
		n = USB_DT_ENDPOINT_AUDIO_SIZE;
	else if (d->bLength >= USB_DT_ENDPOINT_SIZE)
		n = USB_DT_ENDPOINT_SIZE;
	else {
		dev_warn(ddev, "config %d interface %d altsetting %d has an "
		    "invalid endpoint descriptor of length %d, skipping\n",
		    cfgno, inum, asnum, d->bLength);
		goto skip_to_next_endpoint_or_interface_descriptor;
	}

	i = d->bEndpointAddress & ~USB_ENDPOINT_DIR_MASK;
	if (i >= 16 || i == 0) {
		dev_warn(ddev, "config %d interface %d altsetting %d has an "
		    "invalid endpoint with address 0x%X, skipping\n",
		    cfgno, inum, asnum, d->bEndpointAddress);
		goto skip_to_next_endpoint_or_interface_descriptor;
	}

	/* Only store as many endpoints as we have room for */
	if (ifp->desc.bNumEndpoints >= num_ep)
		goto skip_to_next_endpoint_or_interface_descriptor;

	/* Check for duplicate endpoint addresses */
	for (i = 0; i < ifp->desc.bNumEndpoints; ++i) {
		if (ifp->endpoint[i].desc.bEndpointAddress ==
		    d->bEndpointAddress) {
			dev_warn(ddev, "config %d interface %d altsetting %d has a duplicate endpoint with address 0x%X, skipping\n",
			    cfgno, inum, asnum, d->bEndpointAddress);
			goto skip_to_next_endpoint_or_interface_descriptor;
		}
	}

	endpoint = &ifp->endpoint[ifp->desc.bNumEndpoints];
	++ifp->desc.bNumEndpoints;

	memcpy(&endpoint->desc, d, n);
	INIT_LIST_HEAD(&endpoint->urb_list);

	/*
	 * Fix up bInterval values outside the legal range.
	 * Use 10 or 8 ms if no proper value can be guessed.
	 */
	i = 0;		/* i = min, j = max, n = default */
	j = 255;
	if (usb_endpoint_xfer_int(d)) {
		i = 1;
		switch (to_usb_device(ddev)->speed) {
		case USB_SPEED_SUPER_PLUS:
		case USB_SPEED_SUPER:
		case USB_SPEED_HIGH:
			/*
			 * Many device manufacturers are using full-speed
			 * bInterval values in high-speed interrupt endpoint
			 * descriptors. Try to fix those and fall back to an
			 * 8-ms default value otherwise.
			 */
			n = fls(d->bInterval*8);
			if (n == 0)
				n = 7;	/* 8 ms = 2^(7-1) uframes */
			j = 16;

			/*
			 * Adjust bInterval for quirked devices.
			 */
			/*
			 * This quirk fixes bIntervals reported in ms.
			 */
			if (to_usb_device(ddev)->quirks &
				USB_QUIRK_LINEAR_FRAME_INTR_BINTERVAL) {
				n = clamp(fls(d->bInterval) + 3, i, j);
				i = j = n;
			}
			/*
			 * This quirk fixes bIntervals reported in
			 * linear microframes.
			 */
			if (to_usb_device(ddev)->quirks &
				USB_QUIRK_LINEAR_UFRAME_INTR_BINTERVAL) {
				n = clamp(fls(d->bInterval), i, j);
				i = j = n;
			}
			break;
		default:		/* USB_SPEED_FULL or _LOW */
			/*
			 * For low-speed, 10 ms is the official minimum.
			 * But some "overclocked" devices might want faster
			 * polling so we'll allow it.
			 */
			n = 10;
			break;
		}
	} else if (usb_endpoint_xfer_isoc(d)) {
		i = 1;
		j = 16;
		switch (to_usb_device(ddev)->speed) {
		case USB_SPEED_HIGH:
			n = 7;		/* 8 ms = 2^(7-1) uframes */
			break;
		default:		/* USB_SPEED_FULL */
			n = 4;		/* 8 ms = 2^(4-1) frames */
			break;
		}
	}
	if (d->bInterval < i || d->bInterval > j) {
		dev_warn(ddev, "config %d interface %d altsetting %d "
		    "endpoint 0x%X has an invalid bInterval %d, "
		    "changing to %d\n",
		    cfgno, inum, asnum,
		    d->bEndpointAddress, d->bInterval, n);
		endpoint->desc.bInterval = n;
	}

	/* Some buggy low-speed devices have Bulk endpoints, which is
	 * explicitly forbidden by the USB spec.  In an attempt to make
	 * them usable, we will try treating them as Interrupt endpoints.
	 */
	if (to_usb_device(ddev)->speed == USB_SPEED_LOW &&
			usb_endpoint_xfer_bulk(d)) {
		dev_warn(ddev, "config %d interface %d altsetting %d "
		    "endpoint 0x%X is Bulk; changing to Interrupt\n",
		    cfgno, inum, asnum, d->bEndpointAddress);
		endpoint->desc.bmAttributes = USB_ENDPOINT_XFER_INT;
		endpoint->desc.bInterval = 1;
		if (usb_endpoint_maxp(&endpoint->desc) > 8)
			endpoint->desc.wMaxPacketSize = cpu_to_le16(8);
	}

	/* Validate the wMaxPacketSize field */
	maxp = usb_endpoint_maxp(&endpoint->desc);

	/* Find the highest legal maxpacket size for this endpoint */
	i = 0;		/* additional transactions per microframe */
	switch (to_usb_device(ddev)->speed) {
	case USB_SPEED_LOW:
		maxpacket_maxes = low_speed_maxpacket_maxes;
		break;
	case USB_SPEED_FULL:
		maxpacket_maxes = full_speed_maxpacket_maxes;
		break;
	case USB_SPEED_HIGH:
		/* Bits 12..11 are allowed only for HS periodic endpoints */
		if (usb_endpoint_xfer_int(d) || usb_endpoint_xfer_isoc(d)) {
			i = maxp & (BIT(12) | BIT(11));
			maxp &= ~i;
		}
		/* fallthrough */
	default:
		maxpacket_maxes = high_speed_maxpacket_maxes;
		break;
	case USB_SPEED_SUPER:
	case USB_SPEED_SUPER_PLUS:
		maxpacket_maxes = super_speed_maxpacket_maxes;
		break;
	}
	j = maxpacket_maxes[usb_endpoint_type(&endpoint->desc)];

	if (maxp > j) {
		dev_warn(ddev, "config %d interface %d altsetting %d endpoint 0x%X has invalid maxpacket %d, setting to %d\n",
		    cfgno, inum, asnum, d->bEndpointAddress, maxp, j);
		maxp = j;
		endpoint->desc.wMaxPacketSize = cpu_to_le16(i | maxp);
	}

	/*
	 * Some buggy high speed devices have bulk endpoints using
	 * maxpacket sizes other than 512.  High speed HCDs may not
	 * be able to handle that particular bug, so let's warn...
	 */
	if (to_usb_device(ddev)->speed == USB_SPEED_HIGH
			&& usb_endpoint_xfer_bulk(d)) {
		if (maxp != 512)
			dev_warn(ddev, "config %d interface %d altsetting %d "
				"bulk endpoint 0x%X has invalid maxpacket %d\n",
				cfgno, inum, asnum, d->bEndpointAddress,
				maxp);
	}

	/* Parse a possible SuperSpeed endpoint companion descriptor */
	if (to_usb_device(ddev)->speed >= USB_SPEED_SUPER)
		usb_parse_ss_endpoint_companion(ddev, cfgno,
				inum, asnum, endpoint, buffer, size);

	/* Skip over any Class Specific or Vendor Specific descriptors;
	 * find the next endpoint or interface descriptor */
	endpoint->extra = buffer;
	i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
			USB_DT_INTERFACE, &n);
	endpoint->extralen = i;
	retval = buffer - buffer0 + i;
	if (n > 0)
		dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
		    n, plural(n), "endpoint");
	return retval;

skip_to_next_endpoint_or_interface_descriptor:
	i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
	    USB_DT_INTERFACE, NULL);
	return buffer - buffer0 + i;
}

void usb_release_interface_cache(struct kref *ref)
{
	struct usb_interface_cache *intfc = ref_to_usb_interface_cache(ref);
	int j;

	for (j = 0; j < intfc->num_altsetting; j++) {
		struct usb_host_interface *alt = &intfc->altsetting[j];

		kfree(alt->endpoint);
		kfree(alt->string);
	}
	kfree(intfc);
}

static int usb_parse_interface(struct device *ddev, int cfgno,
    struct usb_host_config *config, unsigned char *buffer, int size,
    u8 inums[], u8 nalts[])
{
	unsigned char *buffer0 = buffer;
	struct usb_interface_descriptor	*d;
	int inum, asnum;
	struct usb_interface_cache *intfc;
	struct usb_host_interface *alt;
	int i, n;
	int len, retval;
	int num_ep, num_ep_orig;

	d = (struct usb_interface_descriptor *) buffer;
	buffer += d->bLength;
	size -= d->bLength;

	if (d->bLength < USB_DT_INTERFACE_SIZE)
		goto skip_to_next_interface_descriptor;

	/* Which interface entry is this? */
	intfc = NULL;
	inum = d->bInterfaceNumber;
	for (i = 0; i < config->desc.bNumInterfaces; ++i) {
		if (inums[i] == inum) {
			intfc = config->intf_cache[i];
			break;
		}
	}
	if (!intfc || intfc->num_altsetting >= nalts[i])
		goto skip_to_next_interface_descriptor;

	/* Check for duplicate altsetting entries */
	asnum = d->bAlternateSetting;
	for ((i = 0, alt = &intfc->altsetting[0]);
	      i < intfc->num_altsetting;
	     (++i, ++alt)) {
		if (alt->desc.bAlternateSetting == asnum) {
			dev_warn(ddev, "Duplicate descriptor for config %d "
			    "interface %d altsetting %d, skipping\n",
			    cfgno, inum, asnum);
			goto skip_to_next_interface_descriptor;
		}
	}

	++intfc->num_altsetting;
	memcpy(&alt->desc, d, USB_DT_INTERFACE_SIZE);

	/* Skip over any Class Specific or Vendor Specific descriptors;
	 * find the first endpoint or interface descriptor */
	alt->extra = buffer;
	i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
	    USB_DT_INTERFACE, &n);
	alt->extralen = i;
	if (n > 0)
		dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
		    n, plural(n), "interface");
	buffer += i;
	size -= i;

	/* Allocate space for the right(?) number of endpoints */
	num_ep = num_ep_orig = alt->desc.bNumEndpoints;
	alt->desc.bNumEndpoints = 0;		/* Use as a counter */
	if (num_ep > USB_MAXENDPOINTS) {
		dev_warn(ddev, "too many endpoints for config %d interface %d "
		    "altsetting %d: %d, using maximum allowed: %d\n",
		    cfgno, inum, asnum, num_ep, USB_MAXENDPOINTS);
		num_ep = USB_MAXENDPOINTS;
	}

	if (num_ep > 0) {
		/* Can't allocate 0 bytes */
		len = sizeof(struct usb_host_endpoint) * num_ep;
		alt->endpoint = kzalloc(len, GFP_KERNEL);
		if (!alt->endpoint)
			return -ENOMEM;
	}

	/* Parse all the endpoint descriptors */
	n = 0;
	while (size > 0) {
		if (((struct usb_descriptor_header *) buffer)->bDescriptorType
		     == USB_DT_INTERFACE)
			break;
		retval = usb_parse_endpoint(ddev, cfgno, inum, asnum, alt,
		    num_ep, buffer, size);
		if (retval < 0)
			return retval;
		++n;

		buffer += retval;
		size -= retval;
	}

	if (n != num_ep_orig)
		dev_warn(ddev, "config %d interface %d altsetting %d has %d "
		    "endpoint descriptor%s, different from the interface "
		    "descriptor's value: %d\n",
		    cfgno, inum, asnum, n, plural(n), num_ep_orig);
	return buffer - buffer0;

skip_to_next_interface_descriptor:
	i = find_next_descriptor(buffer, size, USB_DT_INTERFACE,
	    USB_DT_INTERFACE, NULL);
	return buffer - buffer0 + i;
}

static int usb_parse_configuration(struct usb_device *dev, int cfgidx,
    struct usb_host_config *config, unsigned char *buffer, int size)
{
	struct device *ddev = &dev->dev;
	unsigned char *buffer0 = buffer;
	int cfgno;
	int nintf, nintf_orig;
	int i, j, n;
	struct usb_interface_cache *intfc;
	unsigned char *buffer2;
	int size2;
	struct usb_descriptor_header *header;
	int len, retval;
	u8 inums[USB_MAXINTERFACES], nalts[USB_MAXINTERFACES];
	unsigned iad_num = 0;

	memcpy(&config->desc, buffer, USB_DT_CONFIG_SIZE);
	if (config->desc.bDescriptorType != USB_DT_CONFIG ||
	    config->desc.bLength < USB_DT_CONFIG_SIZE ||
	    config->desc.bLength > size) {
		dev_err(ddev, "invalid descriptor for config index %d: "
		    "type = 0x%X, length = %d\n", cfgidx,
		    config->desc.bDescriptorType, config->desc.bLength);
		return -EINVAL;
	}
	cfgno = config->desc.bConfigurationValue;

	buffer += config->desc.bLength;
	size -= config->desc.bLength;

	nintf = nintf_orig = config->desc.bNumInterfaces;
	if (nintf > USB_MAXINTERFACES) {
		dev_warn(ddev, "config %d has too many interfaces: %d, "
		    "using maximum allowed: %d\n",
		    cfgno, nintf, USB_MAXINTERFACES);
		nintf = USB_MAXINTERFACES;
	}

	/* Go through the descriptors, checking their length and counting the
	 * number of altsettings for each interface */
	n = 0;
	for ((buffer2 = buffer, size2 = size);
	      size2 > 0;
	     (buffer2 += header->bLength, size2 -= header->bLength)) {

		if (size2 < sizeof(struct usb_descriptor_header)) {
			dev_warn(ddev, "config %d descriptor has %d excess "
			    "byte%s, ignoring\n",
			    cfgno, size2, plural(size2));
			break;
		}

		header = (struct usb_descriptor_header *) buffer2;
		if ((header->bLength > size2) || (header->bLength < 2)) {
			dev_warn(ddev, "config %d has an invalid descriptor "
			    "of length %d, skipping remainder of the config\n",
			    cfgno, header->bLength);
			break;
		}

		if (header->bDescriptorType == USB_DT_INTERFACE) {
			struct usb_interface_descriptor *d;
			int inum;

			d = (struct usb_interface_descriptor *) header;
			if (d->bLength < USB_DT_INTERFACE_SIZE) {
				dev_warn(ddev, "config %d has an invalid "
				    "interface descriptor of length %d, "
				    "skipping\n", cfgno, d->bLength);
				continue;
			}

			inum = d->bInterfaceNumber;

			if ((dev->quirks & USB_QUIRK_HONOR_BNUMINTERFACES) &&
			    n >= nintf_orig) {
				dev_warn(ddev, "config %d has more interface "
				    "descriptors, than it declares in "
				    "bNumInterfaces, ignoring interface "
				    "number: %d\n", cfgno, inum);
				continue;
			}

			if (inum >= nintf_orig)
				dev_warn(ddev, "config %d has an invalid "
				    "interface number: %d but max is %d\n",
				    cfgno, inum, nintf_orig - 1);

			/* Have we already encountered this interface?
			 * Count its altsettings */
			for (i = 0; i < n; ++i) {
				if (inums[i] == inum)
					break;
			}
			if (i < n) {
				if (nalts[i] < 255)
					++nalts[i];
			} else if (n < USB_MAXINTERFACES) {
				inums[n] = inum;
				nalts[n] = 1;
				++n;
			}

		} else if (header->bDescriptorType ==
				USB_DT_INTERFACE_ASSOCIATION) {
			struct usb_interface_assoc_descriptor *d;

			d = (struct usb_interface_assoc_descriptor *)header;
			if (d->bLength < USB_DT_INTERFACE_ASSOCIATION_SIZE) {
				dev_warn(ddev,
					 "config %d has an invalid interface association descriptor of length %d, skipping\n",
					 cfgno, d->bLength);
				continue;
			}

			if (iad_num == USB_MAXIADS) {
				dev_warn(ddev, "found more Interface "
					       "Association Descriptors "
					       "than allocated for in "
					       "configuration %d\n", cfgno);
			} else {
				config->intf_assoc[iad_num] = d;
				iad_num++;
			}

		} else if (header->bDescriptorType == USB_DT_DEVICE ||
			    header->bDescriptorType == USB_DT_CONFIG)
			dev_warn(ddev, "config %d contains an unexpected "
			    "descriptor of type 0x%X, skipping\n",
			    cfgno, header->bDescriptorType);

	}	/* for ((buffer2 = buffer, size2 = size); ...) */
	size = buffer2 - buffer;
	config->desc.wTotalLength = cpu_to_le16(buffer2 - buffer0);

	if (n != nintf)
		dev_warn(ddev, "config %d has %d interface%s, different from "
		    "the descriptor's value: %d\n",
		    cfgno, n, plural(n), nintf_orig);
	else if (n == 0)
		dev_warn(ddev, "config %d has no interfaces?\n", cfgno);
	config->desc.bNumInterfaces = nintf = n;

	/* Check for missing interface numbers */
	for (i = 0; i < nintf; ++i) {
		for (j = 0; j < nintf; ++j) {
			if (inums[j] == i)
				break;
		}
		if (j >= nintf)
			dev_warn(ddev, "config %d has no interface number "
			    "%d\n", cfgno, i);
	}

	/* Allocate the usb_interface_caches and altsetting arrays */
	for (i = 0; i < nintf; ++i) {
		j = nalts[i];
		if (j > USB_MAXALTSETTING) {
			dev_warn(ddev, "too many alternate settings for "
			    "config %d interface %d: %d, "
			    "using maximum allowed: %d\n",
			    cfgno, inums[i], j, USB_MAXALTSETTING);
			nalts[i] = j = USB_MAXALTSETTING;
		}

		len = sizeof(*intfc) + sizeof(struct usb_host_interface) * j;
		config->intf_cache[i] = intfc = kzalloc(len, GFP_KERNEL);
		if (!intfc)
			return -ENOMEM;
		kref_init(&intfc->ref);
	}

	/* FIXME: parse the BOS descriptor */

	/* Skip over any Class Specific or Vendor Specific descriptors;
	 * find the first interface descriptor */
	config->extra = buffer;
	i = find_next_descriptor(buffer, size, USB_DT_INTERFACE,
	    USB_DT_INTERFACE, &n);
	config->extralen = i;
	if (n > 0)
		dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
		    n, plural(n), "configuration");
	buffer += i;
	size -= i;

	/* Parse all the interface/altsetting descriptors */
	while (size > 0) {
		retval = usb_parse_interface(ddev, cfgno, config,
		    buffer, size, inums, nalts);
		if (retval < 0)
			return retval;

		buffer += retval;
		size -= retval;
	}

	/* Check for missing altsettings */
	for (i = 0; i < nintf; ++i) {
		intfc = config->intf_cache[i];
		for (j = 0; j < intfc->num_altsetting; ++j) {
			for (n = 0; n < intfc->num_altsetting; ++n) {
				if (intfc->altsetting[n].desc.
				    bAlternateSetting == j)
					break;
			}
			if (n >= intfc->num_altsetting)
				dev_warn(ddev, "config %d interface %d has no "
				    "altsetting %d\n", cfgno, inums[i], j);
		}
	}

	return 0;
}

/* hub-only!! ... and only exported for reset/reinit path.
 * otherwise used internally on disconnect/destroy path
 */
void usb_destroy_configuration(struct usb_device *dev)
{
	int c, i;

	if (!dev->config)
		return;

	if (dev->rawdescriptors) {
		for (i = 0; i < dev->descriptor.bNumConfigurations; i++)
			kfree(dev->rawdescriptors[i]);

		kfree(dev->rawdescriptors);
		dev->rawdescriptors = NULL;
	}

	for (c = 0; c < dev->descriptor.bNumConfigurations; c++) {
		struct usb_host_config *cf = &dev->config[c];

		kfree(cf->string);
		for (i = 0; i < cf->desc.bNumInterfaces; i++) {
			if (cf->intf_cache[i])
				kref_put(&cf->intf_cache[i]->ref,
					  usb_release_interface_cache);
		}
	}
	kfree(dev->config);
	dev->config = NULL;
}


/*
 * Get the USB config descriptors, cache and parse'em
 *
 * hub-only!! ... and only in reset path, or usb_new_device()
 * (used by real hubs and virtual root hubs)
 */
int usb_get_configuration(struct usb_device *dev)
{
	struct device *ddev = &dev->dev;
	int ncfg = dev->descriptor.bNumConfigurations;
	int result = 0;
	unsigned int cfgno, length;
	unsigned char *bigbuffer;
	struct usb_config_descriptor *desc;

	cfgno = 0;
	result = -ENOMEM;
	if (ncfg > USB_MAXCONFIG) {
		dev_warn(ddev, "too many configurations: %d, "
		    "using maximum allowed: %d\n", ncfg, USB_MAXCONFIG);
		dev->descriptor.bNumConfigurations = ncfg = USB_MAXCONFIG;
	}

	if (ncfg < 1) {
		dev_err(ddev, "no configurations\n");
		return -EINVAL;
	}

	length = ncfg * sizeof(struct usb_host_config);
	dev->config = kzalloc(length, GFP_KERNEL);
	if (!dev->config)
		goto err2;

	length = ncfg * sizeof(char *);
	dev->rawdescriptors = kzalloc(length, GFP_KERNEL);
	if (!dev->rawdescriptors)
		goto err2;

	desc = kmalloc(USB_DT_CONFIG_SIZE, GFP_KERNEL);
	if (!desc)
		goto err2;

	result = 0;
	for (; cfgno < ncfg; cfgno++) {
		/* We grab just the first descriptor so we know how long
		 * the whole configuration is */
		result = usb_get_descriptor(dev, USB_DT_CONFIG, cfgno,
		    desc, USB_DT_CONFIG_SIZE);
		if (result < 0) {
			dev_err(ddev, "unable to read config index %d "
			    "descriptor/%s: %d\n", cfgno, "start", result);
			if (result != -EPIPE)
				goto err;
			dev_err(ddev, "chopping to %d config(s)\n", cfgno);
			dev->descriptor.bNumConfigurations = cfgno;
			break;
		} else if (result < 4) {
			dev_err(ddev, "config index %d descriptor too short "
			    "(expected %i, got %i)\n", cfgno,
			    USB_DT_CONFIG_SIZE, result);
			result = -EINVAL;
			goto err;
		}
		length = max((int) le16_to_cpu(desc->wTotalLength),
		    USB_DT_CONFIG_SIZE);

		/* Now that we know the length, get the whole thing */
		bigbuffer = kmalloc(length, GFP_KERNEL);
		if (!bigbuffer) {
			result = -ENOMEM;
			goto err;
		}

		if (dev->quirks & USB_QUIRK_DELAY_INIT)
			msleep(200);

		result = usb_get_descriptor(dev, USB_DT_CONFIG, cfgno,
		    bigbuffer, length);
		if (result < 0) {
			dev_err(ddev, "unable to read config index %d "
			    "descriptor/%s\n", cfgno, "all");
			kfree(bigbuffer);
			goto err;
		}
		if (result < length) {
			dev_warn(ddev, "config index %d descriptor too short "
			    "(expected %i, got %i)\n", cfgno, length, result);
			length = result;
		}

		dev->rawdescriptors[cfgno] = bigbuffer;

		result = usb_parse_configuration(dev, cfgno,
		    &dev->config[cfgno], bigbuffer, length);
		if (result < 0) {
			++cfgno;
			goto err;
		}
	}
	result = 0;

err:
	kfree(desc);
	dev->descriptor.bNumConfigurations = cfgno;
err2:
	if (result == -ENOMEM)
		dev_err(ddev, "out of memory\n");
	return result;
}

void usb_release_bos_descriptor(struct usb_device *dev)
{
	if (dev->bos) {
		kfree(dev->bos->desc);
		kfree(dev->bos);
		dev->bos = NULL;
	}
}

/* Get BOS descriptor set */
int usb_get_bos_descriptor(struct usb_device *dev)
{
	struct device *ddev = &dev->dev;
	struct usb_bos_descriptor *bos;
	struct usb_dev_cap_header *cap;
	unsigned char *buffer;
	int length, total_len, num, i;
	int ret;

	bos = kzalloc(sizeof(struct usb_bos_descriptor), GFP_KERNEL);
	if (!bos)
		return -ENOMEM;

	/* Get BOS descriptor */
	ret = usb_get_descriptor(dev, USB_DT_BOS, 0, bos, USB_DT_BOS_SIZE);
	if (ret < USB_DT_BOS_SIZE) {
		dev_err(ddev, "unable to get BOS descriptor\n");
		if (ret >= 0)
			ret = -ENOMSG;
		kfree(bos);
		return ret;
	}

	length = bos->bLength;
	total_len = le16_to_cpu(bos->wTotalLength);
	num = bos->bNumDeviceCaps;
	kfree(bos);
	if (total_len < length)
		return -EINVAL;

	dev->bos = kzalloc(sizeof(struct usb_host_bos), GFP_KERNEL);
	if (!dev->bos)
		return -ENOMEM;

	/* Now let's get the whole BOS descriptor set */
	buffer = kzalloc(total_len, GFP_KERNEL);
	if (!buffer) {
		ret = -ENOMEM;
		goto err;
	}
	dev->bos->desc = (struct usb_bos_descriptor *)buffer;

	ret = usb_get_descriptor(dev, USB_DT_BOS, 0, buffer, total_len);
	if (ret < total_len) {
		dev_err(ddev, "unable to get BOS descriptor set\n");
		if (ret >= 0)
			ret = -ENOMSG;
		goto err;
	}
	total_len -= length;

	for (i = 0; i < num; i++) {
		buffer += length;
		cap = (struct usb_dev_cap_header *)buffer;

		if (total_len < sizeof(*cap) || total_len < cap->bLength) {
			dev->bos->desc->bNumDeviceCaps = i;
			break;
		}
		length = cap->bLength;
		total_len -= length;

		if (cap->bDescriptorType != USB_DT_DEVICE_CAPABILITY) {
			dev_warn(ddev, "descriptor type invalid, skip\n");
			continue;
		}

		switch (cap->bDevCapabilityType) {
		case USB_CAP_TYPE_WIRELESS_USB:
			/* Wireless USB cap descriptor is handled by wusb */
			break;
		case USB_CAP_TYPE_EXT:
			dev->bos->ext_cap =
				(struct usb_ext_cap_descriptor *)buffer;
			break;
		case USB_SS_CAP_TYPE:
			dev->bos->ss_cap =
				(struct usb_ss_cap_descriptor *)buffer;
			break;
		case USB_SSP_CAP_TYPE:
			dev->bos->ssp_cap =
				(struct usb_ssp_cap_descriptor *)buffer;
			break;
		case CONTAINER_ID_TYPE:
			dev->bos->ss_id =
				(struct usb_ss_container_id_descriptor *)buffer;
			break;
		case USB_PTM_CAP_TYPE:
			dev->bos->ptm_cap =
				(struct usb_ptm_cap_descriptor *)buffer;
		default:
			break;
		}
	}

	return 0;

err:
	usb_release_bos_descriptor(dev);
	return ret;
}