drivers/usb/core/config.c

   1 #include <linux/usb.h>
   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>
   8 #include "usb.h"
   9 #include "hcd.h"
  10
  11 #define USB_MAXALTSETTING               128     /* Hard limit */
  12 #define USB_MAXENDPOINTS                30      /* Hard limit */
  13
  14 #define USB_MAXCONFIG                   8       /* Arbitrary limit */
  15
  16
  17 static inline const char *plural(int n)
  18 {
  19         return (n == 1 ? "" : "s");
  20 }
  21
  22 static int find_next_descriptor(unsigned char *buffer, int size,
  23     int dt1, int dt2, int *num_skipped)
  24 {
  25         struct usb_descriptor_header *h;
  26         int n = 0;
  27         unsigned char *buffer0 = buffer;
  28
  29         /* Find the next descriptor of type dt1 or dt2 */
  30         while (size > 0) {
  31                 h = (struct usb_descriptor_header *) buffer;
  32                 if (h->bDescriptorType == dt1 || h->bDescriptorType == dt2)
  33                         break;
  34                 buffer += h->bLength;
  35                 size -= h->bLength;
  36                 ++n;
  37         }
  38
  39         /* Store the number of descriptors skipped and return the
  40          * number of bytes skipped */
  41         if (num_skipped)
  42                 *num_skipped = n;
  43         return buffer - buffer0;
  44 }
  45
  46 static int usb_parse_endpoint(struct device *ddev, int cfgno, int inum,
  47     int asnum, struct usb_host_interface *ifp, int num_ep,
  48     unsigned char *buffer, int size)
  49 {
  50         unsigned char *buffer0 = buffer;
  51         struct usb_endpoint_descriptor *d;
  52         struct usb_host_endpoint *endpoint;
  53         int n, i, j;
  54
  55         d = (struct usb_endpoint_descriptor *) buffer;
  56         buffer += d->bLength;
  57         size -= d->bLength;
  58
  59         if (d->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE)
  60                 n = USB_DT_ENDPOINT_AUDIO_SIZE;
  61         else if (d->bLength >= USB_DT_ENDPOINT_SIZE)
  62                 n = USB_DT_ENDPOINT_SIZE;
  63         else {
  64                 dev_warn(ddev, "config %d interface %d altsetting %d has an "
  65                     "invalid endpoint descriptor of length %d, skipping\n",
  66                     cfgno, inum, asnum, d->bLength);
  67                 goto skip_to_next_endpoint_or_interface_descriptor;
  68         }
  69
  70         i = d->bEndpointAddress & ~USB_ENDPOINT_DIR_MASK;
  71         if (i >= 16 || i == 0) {
  72                 dev_warn(ddev, "config %d interface %d altsetting %d has an "
  73                     "invalid endpoint with address 0x%X, skipping\n",
  74                     cfgno, inum, asnum, d->bEndpointAddress);
  75                 goto skip_to_next_endpoint_or_interface_descriptor;
  76         }
  77
  78         /* Only store as many endpoints as we have room for */
  79         if (ifp->desc.bNumEndpoints >= num_ep)
  80                 goto skip_to_next_endpoint_or_interface_descriptor;
  81
  82         endpoint = &ifp->endpoint[ifp->desc.bNumEndpoints];
  83         ++ifp->desc.bNumEndpoints;
  84
  85         memcpy(&endpoint->desc, d, n);
  86         INIT_LIST_HEAD(&endpoint->urb_list);
  87
  88         /* Fix up bInterval values outside the legal range. Use 32 ms if no
  89          * proper value can be guessed. */
  90         i = 0;          /* i = min, j = max, n = default */
  91         j = 255;
  92         if (usb_endpoint_xfer_int(d)) {
  93                 i = 1;
  94                 switch (to_usb_device(ddev)->speed) {
  95                 case USB_SPEED_HIGH:
  96                         /* Many device manufacturers are using full-speed
  97                          * bInterval values in high-speed interrupt endpoint
  98                          * descriptors. Try to fix those and fall back to a
  99                          * 32 ms default value otherwise. */
 100                         n = fls(d->bInterval*8);
 101                         if (n == 0)
 102                                 n = 9;  /* 32 ms = 2^(9-1) uframes */
 103                         j = 16;
 104                         break;
 105                 default:                /* USB_SPEED_FULL or _LOW */
 106                         /* For low-speed, 10 ms is the official minimum.
 107                          * But some "overclocked" devices might want faster
 108                          * polling so we'll allow it. */
 109                         n = 32;
 110                         break;
 111                 }
 112         } else if (usb_endpoint_xfer_isoc(d)) {
 113                 i = 1;
 114                 j = 16;
 115                 switch (to_usb_device(ddev)->speed) {
 116                 case USB_SPEED_HIGH:
 117                         n = 9;          /* 32 ms = 2^(9-1) uframes */
 118                         break;
 119                 default:                /* USB_SPEED_FULL */
 120                         n = 6;          /* 32 ms = 2^(6-1) frames */
 121                         break;
 122                 }
 123         }
 124         if (d->bInterval < i || d->bInterval > j) {
 125                 dev_warn(ddev, "config %d interface %d altsetting %d "
 126                     "endpoint 0x%X has an invalid bInterval %d, "
 127                     "changing to %d\n",
 128                     cfgno, inum, asnum,
 129                     d->bEndpointAddress, d->bInterval, n);
 130                 endpoint->desc.bInterval = n;
 131         }
 132
 133         /* Some buggy low-speed devices have Bulk endpoints, which is
 134          * explicitly forbidden by the USB spec.  In an attempt to make
 135          * them usable, we will try treating them as Interrupt endpoints.
 136          */
 137         if (to_usb_device(ddev)->speed == USB_SPEED_LOW &&
 138                         usb_endpoint_xfer_bulk(d)) {
 139                 dev_warn(ddev, "config %d interface %d altsetting %d "
 140                     "endpoint 0x%X is Bulk; changing to Interrupt\n",
 141                     cfgno, inum, asnum, d->bEndpointAddress);
 142                 endpoint->desc.bmAttributes = USB_ENDPOINT_XFER_INT;
 143                 endpoint->desc.bInterval = 1;
 144                 if (le16_to_cpu(endpoint->desc.wMaxPacketSize) > 8)
 145                         endpoint->desc.wMaxPacketSize = cpu_to_le16(8);
 146         }
 147
 148         /* Skip over any Class Specific or Vendor Specific descriptors;
 149          * find the next endpoint or interface descriptor */
 150         endpoint->extra = buffer;
 151         i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
 152             USB_DT_INTERFACE, &n);
 153         endpoint->extralen = i;
 154         if (n > 0)
 155                 dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
 156                     n, plural(n), "endpoint");
 157         return buffer - buffer0 + i;
 158
 159 skip_to_next_endpoint_or_interface_descriptor:
 160         i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
 161             USB_DT_INTERFACE, NULL);
 162         return buffer - buffer0 + i;
 163 }
 164
 165 void usb_release_interface_cache(struct kref *ref)
 166 {
 167         struct usb_interface_cache *intfc = ref_to_usb_interface_cache(ref);
 168         int j;
 169
 170         for (j = 0; j < intfc->num_altsetting; j++) {
 171                 struct usb_host_interface *alt = &intfc->altsetting[j];
 172
 173                 kfree(alt->endpoint);
 174                 kfree(alt->string);
 175         }
 176         kfree(intfc);
 177 }
 178
 179 static int usb_parse_interface(struct device *ddev, int cfgno,
 180     struct usb_host_config *config, unsigned char *buffer, int size,
 181     u8 inums[], u8 nalts[])
 182 {
 183         unsigned char *buffer0 = buffer;
 184         struct usb_interface_descriptor *d;
 185         int inum, asnum;
 186         struct usb_interface_cache *intfc;
 187         struct usb_host_interface *alt;
 188         int i, n;
 189         int len, retval;
 190         int num_ep, num_ep_orig;
 191
 192         d = (struct usb_interface_descriptor *) buffer;
 193         buffer += d->bLength;
 194         size -= d->bLength;
 195
 196         if (d->bLength < USB_DT_INTERFACE_SIZE)
 197                 goto skip_to_next_interface_descriptor;
 198
 199         /* Which interface entry is this? */
 200         intfc = NULL;
 201         inum = d->bInterfaceNumber;
 202         for (i = 0; i < config->desc.bNumInterfaces; ++i) {
 203                 if (inums[i] == inum) {
 204                         intfc = config->intf_cache[i];
 205                         break;
 206                 }
 207         }
 208         if (!intfc || intfc->num_altsetting >= nalts[i])
 209                 goto skip_to_next_interface_descriptor;
 210
 211         /* Check for duplicate altsetting entries */
 212         asnum = d->bAlternateSetting;
 213         for ((i = 0, alt = &intfc->altsetting[0]);
 214               i < intfc->num_altsetting;
 215              (++i, ++alt)) {
 216                 if (alt->desc.bAlternateSetting == asnum) {
 217                         dev_warn(ddev, "Duplicate descriptor for config %d "
 218                             "interface %d altsetting %d, skipping\n",
 219                             cfgno, inum, asnum);
 220                         goto skip_to_next_interface_descriptor;
 221                 }
 222         }
 223
 224         ++intfc->num_altsetting;
 225         memcpy(&alt->desc, d, USB_DT_INTERFACE_SIZE);
 226
 227         /* Skip over any Class Specific or Vendor Specific descriptors;
 228          * find the first endpoint or interface descriptor */
 229         alt->extra = buffer;
 230         i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
 231             USB_DT_INTERFACE, &n);
 232         alt->extralen = i;
 233         if (n > 0)
 234                 dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
 235                     n, plural(n), "interface");
 236         buffer += i;
 237         size -= i;
 238
 239         /* Allocate space for the right(?) number of endpoints */
 240         num_ep = num_ep_orig = alt->desc.bNumEndpoints;
 241         alt->desc.bNumEndpoints = 0;            /* Use as a counter */
 242         if (num_ep > USB_MAXENDPOINTS) {
 243                 dev_warn(ddev, "too many endpoints for config %d interface %d "
 244                     "altsetting %d: %d, using maximum allowed: %d\n",
 245                     cfgno, inum, asnum, num_ep, USB_MAXENDPOINTS);
 246                 num_ep = USB_MAXENDPOINTS;
 247         }
 248
 249         if (num_ep > 0) {
 250                 /* Can't allocate 0 bytes */
 251                 len = sizeof(struct usb_host_endpoint) * num_ep;
 252                 alt->endpoint = kzalloc(len, GFP_KERNEL);
 253                 if (!alt->endpoint)
 254                         return -ENOMEM;
 255         }
 256
 257         /* Parse all the endpoint descriptors */
 258         n = 0;
 259         while (size > 0) {
 260                 if (((struct usb_descriptor_header *) buffer)->bDescriptorType
 261                      == USB_DT_INTERFACE)
 262                         break;
 263                 retval = usb_parse_endpoint(ddev, cfgno, inum, asnum, alt,
 264                     num_ep, buffer, size);
 265                 if (retval < 0)
 266                         return retval;
 267                 ++n;
 268
 269                 buffer += retval;
 270                 size -= retval;
 271         }
 272
 273         if (n != num_ep_orig)
 274                 dev_warn(ddev, "config %d interface %d altsetting %d has %d "
 275                     "endpoint descriptor%s, different from the interface "
 276                     "descriptor's value: %d\n",
 277                     cfgno, inum, asnum, n, plural(n), num_ep_orig);
 278         return buffer - buffer0;
 279
 280 skip_to_next_interface_descriptor:
 281         i = find_next_descriptor(buffer, size, USB_DT_INTERFACE,
 282             USB_DT_INTERFACE, NULL);
 283         return buffer - buffer0 + i;
 284 }
 285
 286 static int usb_parse_configuration(struct device *ddev, int cfgidx,
 287     struct usb_host_config *config, unsigned char *buffer, int size)
 288 {
 289         unsigned char *buffer0 = buffer;
 290         int cfgno;
 291         int nintf, nintf_orig;
 292         int i, j, n;
 293         struct usb_interface_cache *intfc;
 294         unsigned char *buffer2;
 295         int size2;
 296         struct usb_descriptor_header *header;
 297         int len, retval;
 298         u8 inums[USB_MAXINTERFACES], nalts[USB_MAXINTERFACES];
 299         unsigned iad_num = 0;
 300
 301         memcpy(&config->desc, buffer, USB_DT_CONFIG_SIZE);
 302         if (config->desc.bDescriptorType != USB_DT_CONFIG ||
 303             config->desc.bLength < USB_DT_CONFIG_SIZE) {
 304                 dev_err(ddev, "invalid descriptor for config index %d: "
 305                     "type = 0x%X, length = %d\n", cfgidx,
 306                     config->desc.bDescriptorType, config->desc.bLength);
 307                 return -EINVAL;
 308         }
 309         cfgno = config->desc.bConfigurationValue;
 310
 311         buffer += config->desc.bLength;
 312         size -= config->desc.bLength;
 313
 314         nintf = nintf_orig = config->desc.bNumInterfaces;
 315         if (nintf > USB_MAXINTERFACES) {
 316                 dev_warn(ddev, "config %d has too many interfaces: %d, "
 317                     "using maximum allowed: %d\n",
 318                     cfgno, nintf, USB_MAXINTERFACES);
 319                 nintf = USB_MAXINTERFACES;
 320         }
 321
 322         /* Go through the descriptors, checking their length and counting the
 323          * number of altsettings for each interface */
 324         n = 0;
 325         for ((buffer2 = buffer, size2 = size);
 326               size2 > 0;
 327              (buffer2 += header->bLength, size2 -= header->bLength)) {
 328
 329                 if (size2 < sizeof(struct usb_descriptor_header)) {
 330                         dev_warn(ddev, "config %d descriptor has %d excess "
 331                             "byte%s, ignoring\n",
 332                             cfgno, size2, plural(size2));
 333                         break;
 334                 }
 335
 336                 header = (struct usb_descriptor_header *) buffer2;
 337                 if ((header->bLength > size2) || (header->bLength < 2)) {
 338                         dev_warn(ddev, "config %d has an invalid descriptor "
 339                             "of length %d, skipping remainder of the config\n",
 340                             cfgno, header->bLength);
 341                         break;
 342                 }
 343
 344                 if (header->bDescriptorType == USB_DT_INTERFACE) {
 345                         struct usb_interface_descriptor *d;
 346                         int inum;
 347
 348                         d = (struct usb_interface_descriptor *) header;
 349                         if (d->bLength < USB_DT_INTERFACE_SIZE) {
 350                                 dev_warn(ddev, "config %d has an invalid "
 351                                     "interface descriptor of length %d, "
 352                                     "skipping\n", cfgno, d->bLength);
 353                                 continue;
 354                         }
 355
 356                         inum = d->bInterfaceNumber;
 357                         if (inum >= nintf_orig)
 358                                 dev_warn(ddev, "config %d has an invalid "
 359                                     "interface number: %d but max is %d\n",
 360                                     cfgno, inum, nintf_orig - 1);
 361
 362                         /* Have we already encountered this interface?
 363                          * Count its altsettings */
 364                         for (i = 0; i < n; ++i) {
 365                                 if (inums[i] == inum)
 366                                         break;
 367                         }
 368                         if (i < n) {
 369                                 if (nalts[i] < 255)
 370                                         ++nalts[i];
 371                         } else if (n < USB_MAXINTERFACES) {
 372                                 inums[n] = inum;
 373                                 nalts[n] = 1;
 374                                 ++n;
 375                         }
 376
 377                 } else if (header->bDescriptorType ==
 378                                 USB_DT_INTERFACE_ASSOCIATION) {
 379                         if (iad_num == USB_MAXIADS) {
 380                                 dev_warn(ddev, "found more Interface "
 381                                                "Association Descriptors "
 382                                                "than allocated for in "
 383                                                "configuration %d\n", cfgno);
 384                         } else {
 385                                 config->intf_assoc[iad_num] =
 386                                         (struct usb_interface_assoc_descriptor
 387                                         *)header;
 388                                 iad_num++;
 389                         }
 390
 391                 } else if (header->bDescriptorType == USB_DT_DEVICE ||
 392                             header->bDescriptorType == USB_DT_CONFIG)
 393                         dev_warn(ddev, "config %d contains an unexpected "
 394                             "descriptor of type 0x%X, skipping\n",
 395                             cfgno, header->bDescriptorType);
 396
 397         }       /* for ((buffer2 = buffer, size2 = size); ...) */
 398         size = buffer2 - buffer;
 399         config->desc.wTotalLength = cpu_to_le16(buffer2 - buffer0);
 400
 401         if (n != nintf)
 402                 dev_warn(ddev, "config %d has %d interface%s, different from "
 403                     "the descriptor's value: %d\n",
 404                     cfgno, n, plural(n), nintf_orig);
 405         else if (n == 0)
 406                 dev_warn(ddev, "config %d has no interfaces?\n", cfgno);
 407         config->desc.bNumInterfaces = nintf = n;
 408
 409         /* Check for missing interface numbers */
 410         for (i = 0; i < nintf; ++i) {
 411                 for (j = 0; j < nintf; ++j) {
 412                         if (inums[j] == i)
 413                                 break;
 414                 }
 415                 if (j >= nintf)
 416                         dev_warn(ddev, "config %d has no interface number "
 417                             "%d\n", cfgno, i);
 418         }
 419
 420         /* Allocate the usb_interface_caches and altsetting arrays */
 421         for (i = 0; i < nintf; ++i) {
 422                 j = nalts[i];
 423                 if (j > USB_MAXALTSETTING) {
 424                         dev_warn(ddev, "too many alternate settings for "
 425                             "config %d interface %d: %d, "
 426                             "using maximum allowed: %d\n",
 427                             cfgno, inums[i], j, USB_MAXALTSETTING);
 428                         nalts[i] = j = USB_MAXALTSETTING;
 429                 }
 430
 431                 len = sizeof(*intfc) + sizeof(struct usb_host_interface) * j;
 432                 config->intf_cache[i] = intfc = kzalloc(len, GFP_KERNEL);
 433                 if (!intfc)
 434                         return -ENOMEM;
 435                 kref_init(&intfc->ref);
 436         }
 437
 438         /* Skip over any Class Specific or Vendor Specific descriptors;
 439          * find the first interface descriptor */
 440         config->extra = buffer;
 441         i = find_next_descriptor(buffer, size, USB_DT_INTERFACE,
 442             USB_DT_INTERFACE, &n);
 443         config->extralen = i;
 444         if (n > 0)
 445                 dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
 446                     n, plural(n), "configuration");
 447         buffer += i;
 448         size -= i;
 449
 450         /* Parse all the interface/altsetting descriptors */
 451         while (size > 0) {
 452                 retval = usb_parse_interface(ddev, cfgno, config,
 453                     buffer, size, inums, nalts);
 454                 if (retval < 0)
 455                         return retval;
 456
 457                 buffer += retval;
 458                 size -= retval;
 459         }
 460
 461         /* Check for missing altsettings */
 462         for (i = 0; i < nintf; ++i) {
 463                 intfc = config->intf_cache[i];
 464                 for (j = 0; j < intfc->num_altsetting; ++j) {
 465                         for (n = 0; n < intfc->num_altsetting; ++n) {
 466                                 if (intfc->altsetting[n].desc.
 467                                     bAlternateSetting == j)
 468                                         break;
 469                         }
 470                         if (n >= intfc->num_altsetting)
 471                                 dev_warn(ddev, "config %d interface %d has no "
 472                                     "altsetting %d\n", cfgno, inums[i], j);
 473                 }
 474         }
 475
 476         return 0;
 477 }
 478
 479 /* hub-only!! ... and only exported for reset/reinit path.
 480  * otherwise used internally on disconnect/destroy path
 481  */
 482 void usb_destroy_configuration(struct usb_device *dev)
 483 {
 484         int c, i;
 485
 486         if (!dev->config)
 487                 return;
 488
 489         if (dev->rawdescriptors) {
 490                 for (i = 0; i < dev->descriptor.bNumConfigurations; i++)
 491                         kfree(dev->rawdescriptors[i]);
 492
 493                 kfree(dev->rawdescriptors);
 494                 dev->rawdescriptors = NULL;
 495         }
 496
 497         for (c = 0; c < dev->descriptor.bNumConfigurations; c++) {
 498                 struct usb_host_config *cf = &dev->config[c];
 499
 500                 kfree(cf->string);
 501                 for (i = 0; i < cf->desc.bNumInterfaces; i++) {
 502                         if (cf->intf_cache[i])
 503                                 kref_put(&cf->intf_cache[i]->ref,
 504                                           usb_release_interface_cache);
 505                 }
 506         }
 507         kfree(dev->config);
 508         dev->config = NULL;
 509 }
 510
 511
 512 /*
 513  * Get the USB config descriptors, cache and parse'em
 514  *
 515  * hub-only!! ... and only in reset path, or usb_new_device()
 516  * (used by real hubs and virtual root hubs)
 517  *
 518  * NOTE: if this is a WUSB device and is not authorized, we skip the
 519  *       whole thing. A non-authorized USB device has no
 520  *       configurations.
 521  */
 522 int usb_get_configuration(struct usb_device *dev)
 523 {
 524         struct device *ddev = &dev->dev;
 525         int ncfg = dev->descriptor.bNumConfigurations;
 526         int result = 0;
 527         unsigned int cfgno, length;
 528         unsigned char *buffer;
 529         unsigned char *bigbuffer;
 530         struct usb_config_descriptor *desc;
 531
 532         cfgno = 0;
 533         if (dev->authorized == 0)       /* Not really an error */
 534                 goto out_not_authorized;
 535         result = -ENOMEM;
 536         if (ncfg > USB_MAXCONFIG) {
 537                 dev_warn(ddev, "too many configurations: %d, "
 538                     "using maximum allowed: %d\n", ncfg, USB_MAXCONFIG);
 539                 dev->descriptor.bNumConfigurations = ncfg = USB_MAXCONFIG;
 540         }
 541
 542         if (ncfg < 1) {
 543                 dev_err(ddev, "no configurations\n");
 544                 return -EINVAL;
 545         }
 546
 547         length = ncfg * sizeof(struct usb_host_config);
 548         dev->config = kzalloc(length, GFP_KERNEL);
 549         if (!dev->config)
 550                 goto err2;
 551
 552         length = ncfg * sizeof(char *);
 553         dev->rawdescriptors = kzalloc(length, GFP_KERNEL);
 554         if (!dev->rawdescriptors)
 555                 goto err2;
 556
 557         buffer = kmalloc(USB_DT_CONFIG_SIZE, GFP_KERNEL);
 558         if (!buffer)
 559                 goto err2;
 560         desc = (struct usb_config_descriptor *)buffer;
 561
 562         result = 0;
 563         for (; cfgno < ncfg; cfgno++) {
 564                 /* We grab just the first descriptor so we know how long
 565                  * the whole configuration is */
 566                 result = usb_get_descriptor(dev, USB_DT_CONFIG, cfgno,
 567                     buffer, USB_DT_CONFIG_SIZE);
 568                 if (result < 0) {
 569                         dev_err(ddev, "unable to read config index %d "
 570                             "descriptor/%s: %d\n", cfgno, "start", result);
 571                         dev_err(ddev, "chopping to %d config(s)\n", cfgno);
 572                         dev->descriptor.bNumConfigurations = cfgno;
 573                         break;
 574                 } else if (result < 4) {
 575                         dev_err(ddev, "config index %d descriptor too short "
 576                             "(expected %i, got %i)\n", cfgno,
 577                             USB_DT_CONFIG_SIZE, result);
 578                         result = -EINVAL;
 579                         goto err;
 580                 }
 581                 length = max((int) le16_to_cpu(desc->wTotalLength),
 582                     USB_DT_CONFIG_SIZE);
 583
 584                 /* Now that we know the length, get the whole thing */
 585                 bigbuffer = kmalloc(length, GFP_KERNEL);
 586                 if (!bigbuffer) {
 587                         result = -ENOMEM;
 588                         goto err;
 589                 }
 590                 result = usb_get_descriptor(dev, USB_DT_CONFIG, cfgno,
 591                     bigbuffer, length);
 592                 if (result < 0) {
 593                         dev_err(ddev, "unable to read config index %d "
 594                             "descriptor/%s\n", cfgno, "all");
 595                         kfree(bigbuffer);
 596                         goto err;
 597                 }
 598                 if (result < length) {
 599                         dev_warn(ddev, "config index %d descriptor too short "
 600                             "(expected %i, got %i)\n", cfgno, length, result);
 601                         length = result;
 602                 }
 603
 604                 dev->rawdescriptors[cfgno] = bigbuffer;
 605
 606                 result = usb_parse_configuration(&dev->dev, cfgno,
 607                     &dev->config[cfgno], bigbuffer, length);
 608                 if (result < 0) {
 609                         ++cfgno;
 610                         goto err;
 611                 }
 612         }
 613         result = 0;
 614
 615 err:
 616         kfree(buffer);
 617 out_not_authorized:
 618         dev->descriptor.bNumConfigurations = cfgno;
 619 err2:
 620         if (result == -ENOMEM)
 621                 dev_err(ddev, "out of memory\n");
 622         return result;
 623 }