2 #include <linux/usb/ch9.h>
3 #include <linux/module.h>
4 #include <linux/init.h>
5 #include <linux/slab.h>
6 #include <linux/device.h>
7 #include <asm/byteorder.h>
11 #define USB_MAXALTSETTING 128 /* Hard limit */
12 #define USB_MAXENDPOINTS 30 /* Hard limit */
14 #define USB_MAXCONFIG 8 /* Arbitrary limit */
17 static inline const char *plural(int n)
19 return (n == 1 ? "" : "s");
22 /* FIXME: this is a kludge */
23 static int find_next_descriptor_more(unsigned char *buffer, int size,
24 int dt1, int dt2, int dt3, int *num_skipped)
26 struct usb_descriptor_header *h;
28 unsigned char *buffer0 = buffer;
30 /* Find the next descriptor of type dt1 or dt2 or dt3 */
32 h = (struct usb_descriptor_header *) buffer;
33 if (h->bDescriptorType == dt1 || h->bDescriptorType == dt2 ||
34 h->bDescriptorType == dt3)
41 /* Store the number of descriptors skipped and return the
42 * number of bytes skipped */
45 return buffer - buffer0;
48 static int find_next_descriptor(unsigned char *buffer, int size,
49 int dt1, int dt2, int *num_skipped)
51 struct usb_descriptor_header *h;
53 unsigned char *buffer0 = buffer;
55 /* Find the next descriptor of type dt1 or dt2 */
57 h = (struct usb_descriptor_header *) buffer;
58 if (h->bDescriptorType == dt1 || h->bDescriptorType == dt2)
65 /* Store the number of descriptors skipped and return the
66 * number of bytes skipped */
69 return buffer - buffer0;
72 static int usb_parse_ss_endpoint_companion(struct device *ddev, int cfgno,
73 int inum, int asnum, struct usb_host_endpoint *ep,
74 int num_ep, unsigned char *buffer, int size)
76 unsigned char *buffer_start = buffer;
77 struct usb_ss_ep_comp_descriptor *desc;
83 /* Allocate space for the SS endpoint companion descriptor */
84 ep->ss_ep_comp = kzalloc(sizeof(struct usb_host_ss_ep_comp),
88 desc = (struct usb_ss_ep_comp_descriptor *) buffer;
89 if (desc->bDescriptorType != USB_DT_SS_ENDPOINT_COMP) {
90 dev_warn(ddev, "No SuperSpeed endpoint companion for config %d "
91 " interface %d altsetting %d ep %d: "
92 "using minimum values\n",
93 cfgno, inum, asnum, ep->desc.bEndpointAddress);
94 ep->ss_ep_comp->desc.bLength = USB_DT_SS_EP_COMP_SIZE;
95 ep->ss_ep_comp->desc.bDescriptorType = USB_DT_SS_ENDPOINT_COMP;
96 ep->ss_ep_comp->desc.bMaxBurst = 0;
98 * Leave bmAttributes as zero, which will mean no streams for
99 * bulk, and isoc won't support multiple bursts of packets.
100 * With bursts of only one packet, and a Mult of 1, the max
101 * amount of data moved per endpoint service interval is one
104 if (usb_endpoint_xfer_isoc(&ep->desc) ||
105 usb_endpoint_xfer_int(&ep->desc))
106 ep->ss_ep_comp->desc.wBytesPerInterval =
107 ep->desc.wMaxPacketSize;
109 * The next descriptor is for an Endpoint or Interface,
110 * no extra descriptors to copy into the companion structure,
111 * and we didn't eat up any of the buffer.
116 memcpy(&ep->ss_ep_comp->desc, desc, USB_DT_SS_EP_COMP_SIZE);
117 desc = &ep->ss_ep_comp->desc;
118 buffer += desc->bLength;
119 size -= desc->bLength;
121 /* Eat up the other descriptors we don't care about */
122 ep->ss_ep_comp->extra = buffer;
123 i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
124 USB_DT_INTERFACE, &num_skipped);
125 ep->ss_ep_comp->extralen = i;
128 retval = buffer - buffer_start + i;
130 dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
131 num_skipped, plural(num_skipped),
132 "SuperSpeed endpoint companion");
134 /* Check the various values */
135 if (usb_endpoint_xfer_control(&ep->desc) && desc->bMaxBurst != 0) {
136 dev_warn(ddev, "Control endpoint with bMaxBurst = %d in "
137 "config %d interface %d altsetting %d ep %d: "
138 "setting to zero\n", desc->bMaxBurst,
139 cfgno, inum, asnum, ep->desc.bEndpointAddress);
142 if (desc->bMaxBurst > 15) {
143 dev_warn(ddev, "Endpoint with bMaxBurst = %d in "
144 "config %d interface %d altsetting %d ep %d: "
145 "setting to 15\n", desc->bMaxBurst,
146 cfgno, inum, asnum, ep->desc.bEndpointAddress);
147 desc->bMaxBurst = 15;
149 if ((usb_endpoint_xfer_control(&ep->desc) || usb_endpoint_xfer_int(&ep->desc))
150 && desc->bmAttributes != 0) {
151 dev_warn(ddev, "%s endpoint with bmAttributes = %d in "
152 "config %d interface %d altsetting %d ep %d: "
154 usb_endpoint_xfer_control(&ep->desc) ? "Control" : "Bulk",
156 cfgno, inum, asnum, ep->desc.bEndpointAddress);
157 desc->bmAttributes = 0;
159 if (usb_endpoint_xfer_bulk(&ep->desc) && desc->bmAttributes > 16) {
160 dev_warn(ddev, "Bulk endpoint with more than 65536 streams in "
161 "config %d interface %d altsetting %d ep %d: "
163 cfgno, inum, asnum, ep->desc.bEndpointAddress);
164 desc->bmAttributes = 16;
166 if (usb_endpoint_xfer_isoc(&ep->desc) && desc->bmAttributes > 2) {
167 dev_warn(ddev, "Isoc endpoint has Mult of %d in "
168 "config %d interface %d altsetting %d ep %d: "
169 "setting to 3\n", desc->bmAttributes + 1,
170 cfgno, inum, asnum, ep->desc.bEndpointAddress);
171 desc->bmAttributes = 2;
173 if (usb_endpoint_xfer_isoc(&ep->desc)) {
174 max_tx = ep->desc.wMaxPacketSize * (desc->bMaxBurst + 1) *
175 (desc->bmAttributes + 1);
176 } else if (usb_endpoint_xfer_int(&ep->desc)) {
177 max_tx = ep->desc.wMaxPacketSize * (desc->bMaxBurst + 1);
181 if (desc->wBytesPerInterval > max_tx) {
182 dev_warn(ddev, "%s endpoint with wBytesPerInterval of %d in "
183 "config %d interface %d altsetting %d ep %d: "
185 usb_endpoint_xfer_isoc(&ep->desc) ? "Isoc" : "Int",
186 desc->wBytesPerInterval,
187 cfgno, inum, asnum, ep->desc.bEndpointAddress,
189 desc->wBytesPerInterval = max_tx;
195 static int usb_parse_endpoint(struct device *ddev, int cfgno, int inum,
196 int asnum, struct usb_host_interface *ifp, int num_ep,
197 unsigned char *buffer, int size)
199 unsigned char *buffer0 = buffer;
200 struct usb_endpoint_descriptor *d;
201 struct usb_host_endpoint *endpoint;
204 d = (struct usb_endpoint_descriptor *) buffer;
205 buffer += d->bLength;
208 if (d->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE)
209 n = USB_DT_ENDPOINT_AUDIO_SIZE;
210 else if (d->bLength >= USB_DT_ENDPOINT_SIZE)
211 n = USB_DT_ENDPOINT_SIZE;
213 dev_warn(ddev, "config %d interface %d altsetting %d has an "
214 "invalid endpoint descriptor of length %d, skipping\n",
215 cfgno, inum, asnum, d->bLength);
216 goto skip_to_next_endpoint_or_interface_descriptor;
219 i = d->bEndpointAddress & ~USB_ENDPOINT_DIR_MASK;
220 if (i >= 16 || i == 0) {
221 dev_warn(ddev, "config %d interface %d altsetting %d has an "
222 "invalid endpoint with address 0x%X, skipping\n",
223 cfgno, inum, asnum, d->bEndpointAddress);
224 goto skip_to_next_endpoint_or_interface_descriptor;
227 /* Only store as many endpoints as we have room for */
228 if (ifp->desc.bNumEndpoints >= num_ep)
229 goto skip_to_next_endpoint_or_interface_descriptor;
231 endpoint = &ifp->endpoint[ifp->desc.bNumEndpoints];
232 ++ifp->desc.bNumEndpoints;
234 memcpy(&endpoint->desc, d, n);
235 INIT_LIST_HEAD(&endpoint->urb_list);
237 /* Fix up bInterval values outside the legal range. Use 32 ms if no
238 * proper value can be guessed. */
239 i = 0; /* i = min, j = max, n = default */
241 if (usb_endpoint_xfer_int(d)) {
243 switch (to_usb_device(ddev)->speed) {
244 case USB_SPEED_SUPER:
246 /* Many device manufacturers are using full-speed
247 * bInterval values in high-speed interrupt endpoint
248 * descriptors. Try to fix those and fall back to a
249 * 32 ms default value otherwise. */
250 n = fls(d->bInterval*8);
252 n = 9; /* 32 ms = 2^(9-1) uframes */
255 default: /* USB_SPEED_FULL or _LOW */
256 /* For low-speed, 10 ms is the official minimum.
257 * But some "overclocked" devices might want faster
258 * polling so we'll allow it. */
262 } else if (usb_endpoint_xfer_isoc(d)) {
265 switch (to_usb_device(ddev)->speed) {
267 n = 9; /* 32 ms = 2^(9-1) uframes */
269 default: /* USB_SPEED_FULL */
270 n = 6; /* 32 ms = 2^(6-1) frames */
274 if (d->bInterval < i || d->bInterval > j) {
275 dev_warn(ddev, "config %d interface %d altsetting %d "
276 "endpoint 0x%X has an invalid bInterval %d, "
279 d->bEndpointAddress, d->bInterval, n);
280 endpoint->desc.bInterval = n;
283 /* Some buggy low-speed devices have Bulk endpoints, which is
284 * explicitly forbidden by the USB spec. In an attempt to make
285 * them usable, we will try treating them as Interrupt endpoints.
287 if (to_usb_device(ddev)->speed == USB_SPEED_LOW &&
288 usb_endpoint_xfer_bulk(d)) {
289 dev_warn(ddev, "config %d interface %d altsetting %d "
290 "endpoint 0x%X is Bulk; changing to Interrupt\n",
291 cfgno, inum, asnum, d->bEndpointAddress);
292 endpoint->desc.bmAttributes = USB_ENDPOINT_XFER_INT;
293 endpoint->desc.bInterval = 1;
294 if (le16_to_cpu(endpoint->desc.wMaxPacketSize) > 8)
295 endpoint->desc.wMaxPacketSize = cpu_to_le16(8);
299 * Some buggy high speed devices have bulk endpoints using
300 * maxpacket sizes other than 512. High speed HCDs may not
301 * be able to handle that particular bug, so let's warn...
303 if (to_usb_device(ddev)->speed == USB_SPEED_HIGH
304 && usb_endpoint_xfer_bulk(d)) {
307 maxp = le16_to_cpu(endpoint->desc.wMaxPacketSize) & 0x07ff;
309 dev_warn(ddev, "config %d interface %d altsetting %d "
310 "bulk endpoint 0x%X has invalid maxpacket %d\n",
311 cfgno, inum, asnum, d->bEndpointAddress,
314 /* Allocate room for and parse any SS endpoint companion descriptors */
315 if (to_usb_device(ddev)->speed == USB_SPEED_SUPER) {
316 endpoint->extra = buffer;
317 i = find_next_descriptor_more(buffer, size, USB_DT_SS_ENDPOINT_COMP,
318 USB_DT_ENDPOINT, USB_DT_INTERFACE, &n);
319 endpoint->extralen = i;
324 retval = usb_parse_ss_endpoint_companion(ddev, cfgno,
325 inum, asnum, endpoint, num_ep, buffer,
329 retval = buffer - buffer0;
332 retval = buffer - buffer0;
335 /* Skip over any Class Specific or Vendor Specific descriptors;
336 * find the next endpoint or interface descriptor */
337 endpoint->extra = buffer;
338 i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
339 USB_DT_INTERFACE, &n);
340 endpoint->extralen = i;
341 retval = buffer - buffer0 + i;
344 dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
345 n, plural(n), "endpoint");
348 skip_to_next_endpoint_or_interface_descriptor:
349 i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
350 USB_DT_INTERFACE, NULL);
351 return buffer - buffer0 + i;
354 void usb_release_interface_cache(struct kref *ref)
356 struct usb_interface_cache *intfc = ref_to_usb_interface_cache(ref);
359 for (j = 0; j < intfc->num_altsetting; j++) {
360 struct usb_host_interface *alt = &intfc->altsetting[j];
362 kfree(alt->endpoint);
368 static int usb_parse_interface(struct device *ddev, int cfgno,
369 struct usb_host_config *config, unsigned char *buffer, int size,
370 u8 inums[], u8 nalts[])
372 unsigned char *buffer0 = buffer;
373 struct usb_interface_descriptor *d;
375 struct usb_interface_cache *intfc;
376 struct usb_host_interface *alt;
379 int num_ep, num_ep_orig;
381 d = (struct usb_interface_descriptor *) buffer;
382 buffer += d->bLength;
385 if (d->bLength < USB_DT_INTERFACE_SIZE)
386 goto skip_to_next_interface_descriptor;
388 /* Which interface entry is this? */
390 inum = d->bInterfaceNumber;
391 for (i = 0; i < config->desc.bNumInterfaces; ++i) {
392 if (inums[i] == inum) {
393 intfc = config->intf_cache[i];
397 if (!intfc || intfc->num_altsetting >= nalts[i])
398 goto skip_to_next_interface_descriptor;
400 /* Check for duplicate altsetting entries */
401 asnum = d->bAlternateSetting;
402 for ((i = 0, alt = &intfc->altsetting[0]);
403 i < intfc->num_altsetting;
405 if (alt->desc.bAlternateSetting == asnum) {
406 dev_warn(ddev, "Duplicate descriptor for config %d "
407 "interface %d altsetting %d, skipping\n",
409 goto skip_to_next_interface_descriptor;
413 ++intfc->num_altsetting;
414 memcpy(&alt->desc, d, USB_DT_INTERFACE_SIZE);
416 /* Skip over any Class Specific or Vendor Specific descriptors;
417 * find the first endpoint or interface descriptor */
419 i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
420 USB_DT_INTERFACE, &n);
423 dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
424 n, plural(n), "interface");
428 /* Allocate space for the right(?) number of endpoints */
429 num_ep = num_ep_orig = alt->desc.bNumEndpoints;
430 alt->desc.bNumEndpoints = 0; /* Use as a counter */
431 if (num_ep > USB_MAXENDPOINTS) {
432 dev_warn(ddev, "too many endpoints for config %d interface %d "
433 "altsetting %d: %d, using maximum allowed: %d\n",
434 cfgno, inum, asnum, num_ep, USB_MAXENDPOINTS);
435 num_ep = USB_MAXENDPOINTS;
439 /* Can't allocate 0 bytes */
440 len = sizeof(struct usb_host_endpoint) * num_ep;
441 alt->endpoint = kzalloc(len, GFP_KERNEL);
446 /* Parse all the endpoint descriptors */
449 if (((struct usb_descriptor_header *) buffer)->bDescriptorType
452 retval = usb_parse_endpoint(ddev, cfgno, inum, asnum, alt,
453 num_ep, buffer, size);
462 if (n != num_ep_orig)
463 dev_warn(ddev, "config %d interface %d altsetting %d has %d "
464 "endpoint descriptor%s, different from the interface "
465 "descriptor's value: %d\n",
466 cfgno, inum, asnum, n, plural(n), num_ep_orig);
467 return buffer - buffer0;
469 skip_to_next_interface_descriptor:
470 i = find_next_descriptor(buffer, size, USB_DT_INTERFACE,
471 USB_DT_INTERFACE, NULL);
472 return buffer - buffer0 + i;
475 static int usb_parse_configuration(struct device *ddev, int cfgidx,
476 struct usb_host_config *config, unsigned char *buffer, int size)
478 unsigned char *buffer0 = buffer;
480 int nintf, nintf_orig;
482 struct usb_interface_cache *intfc;
483 unsigned char *buffer2;
485 struct usb_descriptor_header *header;
487 u8 inums[USB_MAXINTERFACES], nalts[USB_MAXINTERFACES];
488 unsigned iad_num = 0;
490 memcpy(&config->desc, buffer, USB_DT_CONFIG_SIZE);
491 if (config->desc.bDescriptorType != USB_DT_CONFIG ||
492 config->desc.bLength < USB_DT_CONFIG_SIZE) {
493 dev_err(ddev, "invalid descriptor for config index %d: "
494 "type = 0x%X, length = %d\n", cfgidx,
495 config->desc.bDescriptorType, config->desc.bLength);
498 cfgno = config->desc.bConfigurationValue;
500 buffer += config->desc.bLength;
501 size -= config->desc.bLength;
503 nintf = nintf_orig = config->desc.bNumInterfaces;
504 if (nintf > USB_MAXINTERFACES) {
505 dev_warn(ddev, "config %d has too many interfaces: %d, "
506 "using maximum allowed: %d\n",
507 cfgno, nintf, USB_MAXINTERFACES);
508 nintf = USB_MAXINTERFACES;
511 /* Go through the descriptors, checking their length and counting the
512 * number of altsettings for each interface */
514 for ((buffer2 = buffer, size2 = size);
516 (buffer2 += header->bLength, size2 -= header->bLength)) {
518 if (size2 < sizeof(struct usb_descriptor_header)) {
519 dev_warn(ddev, "config %d descriptor has %d excess "
520 "byte%s, ignoring\n",
521 cfgno, size2, plural(size2));
525 header = (struct usb_descriptor_header *) buffer2;
526 if ((header->bLength > size2) || (header->bLength < 2)) {
527 dev_warn(ddev, "config %d has an invalid descriptor "
528 "of length %d, skipping remainder of the config\n",
529 cfgno, header->bLength);
533 if (header->bDescriptorType == USB_DT_INTERFACE) {
534 struct usb_interface_descriptor *d;
537 d = (struct usb_interface_descriptor *) header;
538 if (d->bLength < USB_DT_INTERFACE_SIZE) {
539 dev_warn(ddev, "config %d has an invalid "
540 "interface descriptor of length %d, "
541 "skipping\n", cfgno, d->bLength);
545 inum = d->bInterfaceNumber;
546 if (inum >= nintf_orig)
547 dev_warn(ddev, "config %d has an invalid "
548 "interface number: %d but max is %d\n",
549 cfgno, inum, nintf_orig - 1);
551 /* Have we already encountered this interface?
552 * Count its altsettings */
553 for (i = 0; i < n; ++i) {
554 if (inums[i] == inum)
560 } else if (n < USB_MAXINTERFACES) {
566 } else if (header->bDescriptorType ==
567 USB_DT_INTERFACE_ASSOCIATION) {
568 if (iad_num == USB_MAXIADS) {
569 dev_warn(ddev, "found more Interface "
570 "Association Descriptors "
571 "than allocated for in "
572 "configuration %d\n", cfgno);
574 config->intf_assoc[iad_num] =
575 (struct usb_interface_assoc_descriptor
580 } else if (header->bDescriptorType == USB_DT_DEVICE ||
581 header->bDescriptorType == USB_DT_CONFIG)
582 dev_warn(ddev, "config %d contains an unexpected "
583 "descriptor of type 0x%X, skipping\n",
584 cfgno, header->bDescriptorType);
586 } /* for ((buffer2 = buffer, size2 = size); ...) */
587 size = buffer2 - buffer;
588 config->desc.wTotalLength = cpu_to_le16(buffer2 - buffer0);
591 dev_warn(ddev, "config %d has %d interface%s, different from "
592 "the descriptor's value: %d\n",
593 cfgno, n, plural(n), nintf_orig);
595 dev_warn(ddev, "config %d has no interfaces?\n", cfgno);
596 config->desc.bNumInterfaces = nintf = n;
598 /* Check for missing interface numbers */
599 for (i = 0; i < nintf; ++i) {
600 for (j = 0; j < nintf; ++j) {
605 dev_warn(ddev, "config %d has no interface number "
609 /* Allocate the usb_interface_caches and altsetting arrays */
610 for (i = 0; i < nintf; ++i) {
612 if (j > USB_MAXALTSETTING) {
613 dev_warn(ddev, "too many alternate settings for "
614 "config %d interface %d: %d, "
615 "using maximum allowed: %d\n",
616 cfgno, inums[i], j, USB_MAXALTSETTING);
617 nalts[i] = j = USB_MAXALTSETTING;
620 len = sizeof(*intfc) + sizeof(struct usb_host_interface) * j;
621 config->intf_cache[i] = intfc = kzalloc(len, GFP_KERNEL);
624 kref_init(&intfc->ref);
627 /* FIXME: parse the BOS descriptor */
629 /* Skip over any Class Specific or Vendor Specific descriptors;
630 * find the first interface descriptor */
631 config->extra = buffer;
632 i = find_next_descriptor(buffer, size, USB_DT_INTERFACE,
633 USB_DT_INTERFACE, &n);
634 config->extralen = i;
636 dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
637 n, plural(n), "configuration");
641 /* Parse all the interface/altsetting descriptors */
643 retval = usb_parse_interface(ddev, cfgno, config,
644 buffer, size, inums, nalts);
652 /* Check for missing altsettings */
653 for (i = 0; i < nintf; ++i) {
654 intfc = config->intf_cache[i];
655 for (j = 0; j < intfc->num_altsetting; ++j) {
656 for (n = 0; n < intfc->num_altsetting; ++n) {
657 if (intfc->altsetting[n].desc.
658 bAlternateSetting == j)
661 if (n >= intfc->num_altsetting)
662 dev_warn(ddev, "config %d interface %d has no "
663 "altsetting %d\n", cfgno, inums[i], j);
670 /* hub-only!! ... and only exported for reset/reinit path.
671 * otherwise used internally on disconnect/destroy path
673 void usb_destroy_configuration(struct usb_device *dev)
680 if (dev->rawdescriptors) {
681 for (i = 0; i < dev->descriptor.bNumConfigurations; i++)
682 kfree(dev->rawdescriptors[i]);
684 kfree(dev->rawdescriptors);
685 dev->rawdescriptors = NULL;
688 for (c = 0; c < dev->descriptor.bNumConfigurations; c++) {
689 struct usb_host_config *cf = &dev->config[c];
692 for (i = 0; i < cf->desc.bNumInterfaces; i++) {
693 if (cf->intf_cache[i])
694 kref_put(&cf->intf_cache[i]->ref,
695 usb_release_interface_cache);
704 * Get the USB config descriptors, cache and parse'em
706 * hub-only!! ... and only in reset path, or usb_new_device()
707 * (used by real hubs and virtual root hubs)
709 * NOTE: if this is a WUSB device and is not authorized, we skip the
710 * whole thing. A non-authorized USB device has no
713 int usb_get_configuration(struct usb_device *dev)
715 struct device *ddev = &dev->dev;
716 int ncfg = dev->descriptor.bNumConfigurations;
718 unsigned int cfgno, length;
719 unsigned char *buffer;
720 unsigned char *bigbuffer;
721 struct usb_config_descriptor *desc;
724 if (dev->authorized == 0) /* Not really an error */
725 goto out_not_authorized;
727 if (ncfg > USB_MAXCONFIG) {
728 dev_warn(ddev, "too many configurations: %d, "
729 "using maximum allowed: %d\n", ncfg, USB_MAXCONFIG);
730 dev->descriptor.bNumConfigurations = ncfg = USB_MAXCONFIG;
734 dev_err(ddev, "no configurations\n");
738 length = ncfg * sizeof(struct usb_host_config);
739 dev->config = kzalloc(length, GFP_KERNEL);
743 length = ncfg * sizeof(char *);
744 dev->rawdescriptors = kzalloc(length, GFP_KERNEL);
745 if (!dev->rawdescriptors)
748 buffer = kmalloc(USB_DT_CONFIG_SIZE, GFP_KERNEL);
751 desc = (struct usb_config_descriptor *)buffer;
754 for (; cfgno < ncfg; cfgno++) {
755 /* We grab just the first descriptor so we know how long
756 * the whole configuration is */
757 result = usb_get_descriptor(dev, USB_DT_CONFIG, cfgno,
758 buffer, USB_DT_CONFIG_SIZE);
760 dev_err(ddev, "unable to read config index %d "
761 "descriptor/%s: %d\n", cfgno, "start", result);
762 dev_err(ddev, "chopping to %d config(s)\n", cfgno);
763 dev->descriptor.bNumConfigurations = cfgno;
765 } else if (result < 4) {
766 dev_err(ddev, "config index %d descriptor too short "
767 "(expected %i, got %i)\n", cfgno,
768 USB_DT_CONFIG_SIZE, result);
772 length = max((int) le16_to_cpu(desc->wTotalLength),
775 /* Now that we know the length, get the whole thing */
776 bigbuffer = kmalloc(length, GFP_KERNEL);
781 result = usb_get_descriptor(dev, USB_DT_CONFIG, cfgno,
784 dev_err(ddev, "unable to read config index %d "
785 "descriptor/%s\n", cfgno, "all");
789 if (result < length) {
790 dev_warn(ddev, "config index %d descriptor too short "
791 "(expected %i, got %i)\n", cfgno, length, result);
795 dev->rawdescriptors[cfgno] = bigbuffer;
797 result = usb_parse_configuration(&dev->dev, cfgno,
798 &dev->config[cfgno], bigbuffer, length);
809 dev->descriptor.bNumConfigurations = cfgno;
811 if (result == -ENOMEM)
812 dev_err(ddev, "out of memory\n");