release/src-rt-6.x/linux/linux-2.6/drivers/usb/core/config.c

   1 #include <linux/usb.h>
   2 #include <linux/usb/ch9.h>
   3 #include <linux/usb/quirks.h>
   4 #include <linux/module.h>
   5 #include <linux/init.h>
   6 #include <linux/slab.h>
   7 #include <linux/device.h>
   8 #include <asm/byteorder.h>
   9 #include "usb.h"
  10 #include "hcd.h"
  11
  12 #define USB_MAXALTSETTING               128     /* Hard limit */
  13 #define USB_MAXENDPOINTS                30      /* Hard limit */
  14
  15 #define USB_MAXCONFIG                   8       /* Arbitrary limit */
  16
  17
  18 static inline const char *plural(int n)
  19 {
  20         return (n == 1 ? "" : "s");
  21 }
  22
  23 static int find_next_descriptor(unsigned char *buffer, int size,
  24     int dt1, int dt2, int *num_skipped)
  25 {
  26         struct usb_descriptor_header *h;
  27         int n = 0;
  28         unsigned char *buffer0 = buffer;
  29
  30         /* Find the next descriptor of type dt1 or dt2 */
  31         while (size > 0) {
  32                 h = (struct usb_descriptor_header *) buffer;
  33                 if (h->bDescriptorType == dt1 || h->bDescriptorType == dt2)
  34                         break;
  35                 buffer += h->bLength;
  36                 size -= h->bLength;
  37                 ++n;
  38         }
  39
  40         /* Store the number of descriptors skipped and return the
  41          * number of bytes skipped */
  42         if (num_skipped)
  43                 *num_skipped = n;
  44         return buffer - buffer0;
  45 }
  46
  47 static int usb_parse_endpoint(struct device *ddev, int cfgno, int inum,
  48     int asnum, struct usb_host_interface *ifp, int num_ep,
  49     unsigned char *buffer, int size)
  50 {
  51         unsigned char *buffer0 = buffer;
  52         struct usb_endpoint_descriptor *d;
  53         struct usb_host_endpoint *endpoint;
  54         int n, i, j;
  55
  56         d = (struct usb_endpoint_descriptor *) buffer;
  57         buffer += d->bLength;
  58         size -= d->bLength;
  59
  60         if (d->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE)
  61                 n = USB_DT_ENDPOINT_AUDIO_SIZE;
  62         else if (d->bLength >= USB_DT_ENDPOINT_SIZE)
  63                 n = USB_DT_ENDPOINT_SIZE;
  64         else {
  65                 dev_warn(ddev, "config %d interface %d altsetting %d has an "
  66                     "invalid endpoint descriptor of length %d, skipping\n",
  67                     cfgno, inum, asnum, d->bLength);
  68                 goto skip_to_next_endpoint_or_interface_descriptor;
  69         }
  70
  71         i = d->bEndpointAddress & ~USB_ENDPOINT_DIR_MASK;
  72         if (i >= 16 || i == 0) {
  73                 dev_warn(ddev, "config %d interface %d altsetting %d has an "
  74                     "invalid endpoint with address 0x%X, skipping\n",
  75                     cfgno, inum, asnum, d->bEndpointAddress);
  76                 goto skip_to_next_endpoint_or_interface_descriptor;
  77         }
  78
  79         /* Only store as many endpoints as we have room for */
  80         if (ifp->desc.bNumEndpoints >= num_ep)
  81                 goto skip_to_next_endpoint_or_interface_descriptor;
  82
  83         endpoint = &ifp->endpoint[ifp->desc.bNumEndpoints];
  84         ++ifp->desc.bNumEndpoints;
  85
  86         memcpy(&endpoint->desc, d, n);
  87         INIT_LIST_HEAD(&endpoint->urb_list);
  88
  89         /* Fix up bInterval values outside the legal range. Use 32 ms if no
  90          * proper value can be guessed. */
  91         i = 0;          /* i = min, j = max, n = default */
  92         j = 255;
  93         if (usb_endpoint_xfer_int(d)) {
  94                 i = 1;
  95                 switch (to_usb_device(ddev)->speed) {
  96                 case USB_SPEED_HIGH:
  97                         /* Many device manufacturers are using full-speed
  98                          * bInterval values in high-speed interrupt endpoint
  99                          * descriptors. Try to fix those and fall back to a
 100                          * 32 ms default value otherwise. */
 101                         n = fls(d->bInterval*8);
 102                         if (n == 0)
 103                                 n = 9;  /* 32 ms = 2^(9-1) uframes */
 104                         j = 16;
 105                         break;
 106                 default:                /* USB_SPEED_FULL or _LOW */
 107                         /* For low-speed, 10 ms is the official minimum.
 108                          * But some "overclocked" devices might want faster
 109                          * polling so we'll allow it. */
 110                         n = 32;
 111                         break;
 112                 }
 113         } else if (usb_endpoint_xfer_isoc(d)) {
 114                 i = 1;
 115                 j = 16;
 116                 switch (to_usb_device(ddev)->speed) {
 117                 case USB_SPEED_HIGH:
 118                         n = 9;          /* 32 ms = 2^(9-1) uframes */
 119                         break;
 120                 default:                /* USB_SPEED_FULL */
 121                         n = 6;          /* 32 ms = 2^(6-1) frames */
 122                         break;
 123                 }
 124         }
 125         if (d->bInterval < i || d->bInterval > j) {
 126                 dev_warn(ddev, "config %d interface %d altsetting %d "
 127                     "endpoint 0x%X has an invalid bInterval %d, "
 128                     "changing to %d\n",
 129                     cfgno, inum, asnum,
 130                     d->bEndpointAddress, d->bInterval, n);
 131                 endpoint->desc.bInterval = n;
 132         }
 133
 134         /* Some buggy low-speed devices have Bulk endpoints, which is
 135          * explicitly forbidden by the USB spec.  In an attempt to make
 136          * them usable, we will try treating them as Interrupt endpoints.
 137          */
 138         if (to_usb_device(ddev)->speed == USB_SPEED_LOW &&
 139                         usb_endpoint_xfer_bulk(d)) {
 140                 dev_warn(ddev, "config %d interface %d altsetting %d "
 141                     "endpoint 0x%X is Bulk; changing to Interrupt\n",
 142                     cfgno, inum, asnum, d->bEndpointAddress);
 143                 endpoint->desc.bmAttributes = USB_ENDPOINT_XFER_INT;
 144                 endpoint->desc.bInterval = 1;
 145                 if (le16_to_cpu(endpoint->desc.wMaxPacketSize) > 8)
 146                         endpoint->desc.wMaxPacketSize = cpu_to_le16(8);
 147         }
 148
 149         /*
 150          * Some buggy high speed devices have bulk endpoints using
 151          * maxpacket sizes other than 512.  High speed HCDs may not
 152          * be able to handle that particular bug, so let's warn...
 153          */
 154         if (to_usb_device(ddev)->speed == USB_SPEED_HIGH
 155                         && usb_endpoint_xfer_bulk(d)) {
 156                 unsigned maxp;
 157
 158                 maxp = le16_to_cpu(endpoint->desc.wMaxPacketSize) & 0x07ff;
 159                 if (maxp != 512)
 160                         dev_warn(ddev, "config %d interface %d altsetting %d "
 161                                 "bulk endpoint 0x%X has invalid maxpacket %d\n",
 162                                 cfgno, inum, asnum, d->bEndpointAddress,
 163                                 maxp);
 164         }
 165
 166         /* Skip over any Class Specific or Vendor Specific descriptors;
 167          * find the next endpoint or interface descriptor */
 168         endpoint->extra = buffer;
 169         i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
 170             USB_DT_INTERFACE, &n);
 171         endpoint->extralen = i;
 172         if (n > 0)
 173                 dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
 174                     n, plural(n), "endpoint");
 175         return buffer - buffer0 + i;
 176
 177 skip_to_next_endpoint_or_interface_descriptor:
 178         i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
 179             USB_DT_INTERFACE, NULL);
 180         return buffer - buffer0 + i;
 181 }
 182
 183 void usb_release_interface_cache(struct kref *ref)
 184 {
 185         struct usb_interface_cache *intfc = ref_to_usb_interface_cache(ref);
 186         int j;
 187
 188         for (j = 0; j < intfc->num_altsetting; j++) {
 189                 struct usb_host_interface *alt = &intfc->altsetting[j];
 190
 191                 kfree(alt->endpoint);
 192                 kfree(alt->string);
 193         }
 194         kfree(intfc);
 195 }
 196
 197 static int usb_parse_interface(struct device *ddev, int cfgno,
 198     struct usb_host_config *config, unsigned char *buffer, int size,
 199     u8 inums[], u8 nalts[])
 200 {
 201         unsigned char *buffer0 = buffer;
 202         struct usb_interface_descriptor *d;
 203         int inum, asnum;
 204         struct usb_interface_cache *intfc;
 205         struct usb_host_interface *alt;
 206         int i, n;
 207         int len, retval;
 208         int num_ep, num_ep_orig;
 209
 210         d = (struct usb_interface_descriptor *) buffer;
 211         buffer += d->bLength;
 212         size -= d->bLength;
 213
 214         if (d->bLength < USB_DT_INTERFACE_SIZE)
 215                 goto skip_to_next_interface_descriptor;
 216
 217         /* Which interface entry is this? */
 218         intfc = NULL;
 219         inum = d->bInterfaceNumber;
 220         for (i = 0; i < config->desc.bNumInterfaces; ++i) {
 221                 if (inums[i] == inum) {
 222                         intfc = config->intf_cache[i];
 223                         break;
 224                 }
 225         }
 226         if (!intfc || intfc->num_altsetting >= nalts[i])
 227                 goto skip_to_next_interface_descriptor;
 228
 229         /* Check for duplicate altsetting entries */
 230         asnum = d->bAlternateSetting;
 231         for ((i = 0, alt = &intfc->altsetting[0]);
 232               i < intfc->num_altsetting;
 233              (++i, ++alt)) {
 234                 if (alt->desc.bAlternateSetting == asnum) {
 235                         dev_warn(ddev, "Duplicate descriptor for config %d "
 236                             "interface %d altsetting %d, skipping\n",
 237                             cfgno, inum, asnum);
 238                         goto skip_to_next_interface_descriptor;
 239                 }
 240         }
 241
 242         ++intfc->num_altsetting;
 243         memcpy(&alt->desc, d, USB_DT_INTERFACE_SIZE);
 244
 245         /* Skip over any Class Specific or Vendor Specific descriptors;
 246          * find the first endpoint or interface descriptor */
 247         alt->extra = buffer;
 248         i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
 249             USB_DT_INTERFACE, &n);
 250         alt->extralen = i;
 251         if (n > 0)
 252                 dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
 253                     n, plural(n), "interface");
 254         buffer += i;
 255         size -= i;
 256
 257         /* Allocate space for the right(?) number of endpoints */
 258         num_ep = num_ep_orig = alt->desc.bNumEndpoints;
 259         alt->desc.bNumEndpoints = 0;            /* Use as a counter */
 260         if (num_ep > USB_MAXENDPOINTS) {
 261                 dev_warn(ddev, "too many endpoints for config %d interface %d "
 262                     "altsetting %d: %d, using maximum allowed: %d\n",
 263                     cfgno, inum, asnum, num_ep, USB_MAXENDPOINTS);
 264                 num_ep = USB_MAXENDPOINTS;
 265         }
 266
 267         if (num_ep > 0) {
 268                 /* Can't allocate 0 bytes */
 269                 len = sizeof(struct usb_host_endpoint) * num_ep;
 270                 alt->endpoint = kzalloc(len, GFP_KERNEL);
 271                 if (!alt->endpoint)
 272                         return -ENOMEM;
 273         }
 274
 275         /* Parse all the endpoint descriptors */
 276         n = 0;
 277         while (size > 0) {
 278                 if (((struct usb_descriptor_header *) buffer)->bDescriptorType
 279                      == USB_DT_INTERFACE)
 280                         break;
 281                 retval = usb_parse_endpoint(ddev, cfgno, inum, asnum, alt,
 282                     num_ep, buffer, size);
 283                 if (retval < 0)
 284                         return retval;
 285                 ++n;
 286
 287                 buffer += retval;
 288                 size -= retval;
 289         }
 290
 291         if (n != num_ep_orig)
 292                 dev_warn(ddev, "config %d interface %d altsetting %d has %d "
 293                     "endpoint descriptor%s, different from the interface "
 294                     "descriptor's value: %d\n",
 295                     cfgno, inum, asnum, n, plural(n), num_ep_orig);
 296         return buffer - buffer0;
 297
 298 skip_to_next_interface_descriptor:
 299         i = find_next_descriptor(buffer, size, USB_DT_INTERFACE,
 300             USB_DT_INTERFACE, NULL);
 301         return buffer - buffer0 + i;
 302 }
 303
 304 static int usb_parse_configuration(struct usb_device *dev, int cfgidx,
 305     struct usb_host_config *config, unsigned char *buffer, int size)
 306 {
 307         struct device *ddev = &dev->dev;
 308         unsigned char *buffer0 = buffer;
 309         int cfgno;
 310         int nintf, nintf_orig;
 311         int i, j, n;
 312         struct usb_interface_cache *intfc;
 313         unsigned char *buffer2;
 314         int size2;
 315         struct usb_descriptor_header *header;
 316         int len, retval;
 317         u8 inums[USB_MAXINTERFACES], nalts[USB_MAXINTERFACES];
 318         unsigned iad_num = 0;
 319
 320         memcpy(&config->desc, buffer, USB_DT_CONFIG_SIZE);
 321         if (config->desc.bDescriptorType != USB_DT_CONFIG ||
 322             config->desc.bLength < USB_DT_CONFIG_SIZE) {
 323                 dev_err(ddev, "invalid descriptor for config index %d: "
 324                     "type = 0x%X, length = %d\n", cfgidx,
 325                     config->desc.bDescriptorType, config->desc.bLength);
 326                 return -EINVAL;
 327         }
 328         cfgno = config->desc.bConfigurationValue;
 329
 330         buffer += config->desc.bLength;
 331         size -= config->desc.bLength;
 332
 333         nintf = nintf_orig = config->desc.bNumInterfaces;
 334         if (nintf > USB_MAXINTERFACES) {
 335                 dev_warn(ddev, "config %d has too many interfaces: %d, "
 336                     "using maximum allowed: %d\n",
 337                     cfgno, nintf, USB_MAXINTERFACES);
 338                 nintf = USB_MAXINTERFACES;
 339         }
 340
 341         /* Go through the descriptors, checking their length and counting the
 342          * number of altsettings for each interface */
 343         n = 0;
 344         for ((buffer2 = buffer, size2 = size);
 345               size2 > 0;
 346              (buffer2 += header->bLength, size2 -= header->bLength)) {
 347
 348                 if (size2 < sizeof(struct usb_descriptor_header)) {
 349                         dev_warn(ddev, "config %d descriptor has %d excess "
 350                             "byte%s, ignoring\n",
 351                             cfgno, size2, plural(size2));
 352                         break;
 353                 }
 354
 355                 header = (struct usb_descriptor_header *) buffer2;
 356                 if ((header->bLength > size2) || (header->bLength < 2)) {
 357                         dev_warn(ddev, "config %d has an invalid descriptor "
 358                             "of length %d, skipping remainder of the config\n",
 359                             cfgno, header->bLength);
 360                         break;
 361                 }
 362
 363                 if (header->bDescriptorType == USB_DT_INTERFACE) {
 364                         struct usb_interface_descriptor *d;
 365                         int inum;
 366
 367                         d = (struct usb_interface_descriptor *) header;
 368                         if (d->bLength < USB_DT_INTERFACE_SIZE) {
 369                                 dev_warn(ddev, "config %d has an invalid "
 370                                     "interface descriptor of length %d, "
 371                                     "skipping\n", cfgno, d->bLength);
 372                                 continue;
 373                         }
 374
 375                         inum = d->bInterfaceNumber;
 376
 377                         if ((dev->quirks & USB_QUIRK_HONOR_BNUMINTERFACES) &&
 378                             n >= nintf_orig) {
 379                                 dev_warn(ddev, "config %d has more interface "
 380                                     "descriptors than it declares in "
 381                                     "bNumInterfaces, ignoring interface "
 382                                     "number: %d\n", cfgno, inum);
 383                                 continue;
 384                         }
 385
 386                         if (inum >= nintf_orig)
 387                                 dev_warn(ddev, "config %d has an invalid "
 388                                     "interface number: %d but max is %d\n",
 389                                     cfgno, inum, nintf_orig - 1);
 390
 391                         /* Have we already encountered this interface?
 392                          * Count its altsettings */
 393                         for (i = 0; i < n; ++i) {
 394                                 if (inums[i] == inum)
 395                                         break;
 396                         }
 397                         if (i < n) {
 398                                 if (nalts[i] < 255)
 399                                         ++nalts[i];
 400                         } else if (n < USB_MAXINTERFACES) {
 401                                 inums[n] = inum;
 402                                 nalts[n] = 1;
 403                                 ++n;
 404                         }
 405
 406                 } else if (header->bDescriptorType ==
 407                                 USB_DT_INTERFACE_ASSOCIATION) {
 408                         if (iad_num == USB_MAXIADS) {
 409                                 dev_warn(ddev, "found more Interface "
 410                                                "Association Descriptors "
 411                                                "than allocated for in "
 412                                                "configuration %d\n", cfgno);
 413                         } else {
 414                                 config->intf_assoc[iad_num] =
 415                                         (struct usb_interface_assoc_descriptor
 416                                         *)header;
 417                                 iad_num++;
 418                         }
 419
 420                 } else if (header->bDescriptorType == USB_DT_DEVICE ||
 421                             header->bDescriptorType == USB_DT_CONFIG)
 422                         dev_warn(ddev, "config %d contains an unexpected "
 423                             "descriptor of type 0x%X, skipping\n",
 424                             cfgno, header->bDescriptorType);
 425
 426         }       /* for ((buffer2 = buffer, size2 = size); ...) */
 427         size = buffer2 - buffer;
 428         config->desc.wTotalLength = cpu_to_le16(buffer2 - buffer0);
 429
 430         if (n != nintf)
 431                 dev_warn(ddev, "config %d has %d interface%s, different from "
 432                     "the descriptor's value: %d\n",
 433                     cfgno, n, plural(n), nintf_orig);
 434         else if (n == 0)
 435                 dev_warn(ddev, "config %d has no interfaces?\n", cfgno);
 436         config->desc.bNumInterfaces = nintf = n;
 437
 438         /* Check for missing interface numbers */
 439         for (i = 0; i < nintf; ++i) {
 440                 for (j = 0; j < nintf; ++j) {
 441                         if (inums[j] == i)
 442                                 break;
 443                 }
 444                 if (j >= nintf)
 445                         dev_warn(ddev, "config %d has no interface number "
 446                             "%d\n", cfgno, i);
 447         }
 448
 449         /* Allocate the usb_interface_caches and altsetting arrays */
 450         for (i = 0; i < nintf; ++i) {
 451                 j = nalts[i];
 452                 if (j > USB_MAXALTSETTING) {
 453                         dev_warn(ddev, "too many alternate settings for "
 454                             "config %d interface %d: %d, "
 455                             "using maximum allowed: %d\n",
 456                             cfgno, inums[i], j, USB_MAXALTSETTING);
 457                         nalts[i] = j = USB_MAXALTSETTING;
 458                 }
 459
 460                 len = sizeof(*intfc) + sizeof(struct usb_host_interface) * j;
 461                 config->intf_cache[i] = intfc = kzalloc(len, GFP_KERNEL);
 462                 if (!intfc)
 463                         return -ENOMEM;
 464                 kref_init(&intfc->ref);
 465         }
 466
 467         /* Skip over any Class Specific or Vendor Specific descriptors;
 468          * find the first interface descriptor */
 469         config->extra = buffer;
 470         i = find_next_descriptor(buffer, size, USB_DT_INTERFACE,
 471             USB_DT_INTERFACE, &n);
 472         config->extralen = i;
 473         if (n > 0)
 474                 dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
 475                     n, plural(n), "configuration");
 476         buffer += i;
 477         size -= i;
 478
 479         /* Parse all the interface/altsetting descriptors */
 480         while (size > 0) {
 481                 retval = usb_parse_interface(ddev, cfgno, config,
 482                     buffer, size, inums, nalts);
 483                 if (retval < 0)
 484                         return retval;
 485
 486                 buffer += retval;
 487                 size -= retval;
 488         }
 489
 490         /* Check for missing altsettings */
 491         for (i = 0; i < nintf; ++i) {
 492                 intfc = config->intf_cache[i];
 493                 for (j = 0; j < intfc->num_altsetting; ++j) {
 494                         for (n = 0; n < intfc->num_altsetting; ++n) {
 495                                 if (intfc->altsetting[n].desc.
 496                                     bAlternateSetting == j)
 497                                         break;
 498                         }
 499                         if (n >= intfc->num_altsetting)
 500                                 dev_warn(ddev, "config %d interface %d has no "
 501                                     "altsetting %d\n", cfgno, inums[i], j);
 502                 }
 503         }
 504
 505         return 0;
 506 }
 507
 508 /* hub-only!! ... and only exported for reset/reinit path.
 509  * otherwise used internally on disconnect/destroy path
 510  */
 511 void usb_destroy_configuration(struct usb_device *dev)
 512 {
 513         int c, i;
 514
 515         if (!dev->config)
 516                 return;
 517
 518         if (dev->rawdescriptors) {
 519                 for (i = 0; i < dev->descriptor.bNumConfigurations; i++)
 520                         kfree(dev->rawdescriptors[i]);
 521
 522                 kfree(dev->rawdescriptors);
 523                 dev->rawdescriptors = NULL;
 524         }
 525
 526         for (c = 0; c < dev->descriptor.bNumConfigurations; c++) {
 527                 struct usb_host_config *cf = &dev->config[c];
 528
 529                 kfree(cf->string);
 530                 for (i = 0; i < cf->desc.bNumInterfaces; i++) {
 531                         if (cf->intf_cache[i])
 532                                 kref_put(&cf->intf_cache[i]->ref,
 533                                           usb_release_interface_cache);
 534                 }
 535         }
 536         kfree(dev->config);
 537         dev->config = NULL;
 538 }
 539
 540
 541 // hub-only!! ... and only in reset path, or usb_new_device()
 542 // (used by real hubs and virtual root hubs)
 543 int usb_get_configuration(struct usb_device *dev)
 544 {
 545         struct device *ddev = &dev->dev;
 546         int ncfg = dev->descriptor.bNumConfigurations;
 547         int result = -ENOMEM;
 548         unsigned int cfgno, length;
 549         unsigned char *bigbuffer;
 550         struct usb_config_descriptor *desc;
 551
 552         if (ncfg > USB_MAXCONFIG) {
 553                 dev_warn(ddev, "too many configurations: %d, "
 554                     "using maximum allowed: %d\n", ncfg, USB_MAXCONFIG);
 555                 dev->descriptor.bNumConfigurations = ncfg = USB_MAXCONFIG;
 556         }
 557
 558         if (ncfg < 1) {
 559                 dev_err(ddev, "no configurations\n");
 560                 return -EINVAL;
 561         }
 562
 563         length = ncfg * sizeof(struct usb_host_config);
 564         dev->config = kzalloc(length, GFP_KERNEL);
 565         if (!dev->config)
 566                 goto err2;
 567
 568         length = ncfg * sizeof(char *);
 569         dev->rawdescriptors = kzalloc(length, GFP_KERNEL);
 570         if (!dev->rawdescriptors)
 571                 goto err2;
 572
 573         desc = kmalloc(USB_DT_CONFIG_SIZE, GFP_KERNEL);
 574         if (!desc)
 575                 goto err2;
 576
 577         for (cfgno = 0; cfgno < ncfg; cfgno++) {
 578                 /* We grab just the first descriptor so we know how long
 579                  * the whole configuration is */
 580                 result = usb_get_descriptor(dev, USB_DT_CONFIG, cfgno,
 581                     desc, USB_DT_CONFIG_SIZE);
 582                 if (result < 0) {
 583                         dev_err(ddev, "unable to read config index %d "
 584                             "descriptor/%s\n", cfgno, "start");
 585                         dev_err(ddev, "chopping to %d config(s)\n", cfgno);
 586                         dev->descriptor.bNumConfigurations = cfgno;
 587                         break;
 588                 } else if (result < 4) {
 589                         dev_err(ddev, "config index %d descriptor too short "
 590                             "(expected %i, got %i)\n", cfgno,
 591                             USB_DT_CONFIG_SIZE, result);
 592                         result = -EINVAL;
 593                         goto err;
 594                 }
 595                 length = max((int) le16_to_cpu(desc->wTotalLength),
 596                     USB_DT_CONFIG_SIZE);
 597
 598                 /* Now that we know the length, get the whole thing */
 599                 bigbuffer = kmalloc(length, GFP_KERNEL);
 600                 if (!bigbuffer) {
 601                         result = -ENOMEM;
 602                         goto err;
 603                 }
 604                 result = usb_get_descriptor(dev, USB_DT_CONFIG, cfgno,
 605                     bigbuffer, length);
 606                 if (result < 0) {
 607                         dev_err(ddev, "unable to read config index %d "
 608                             "descriptor/%s\n", cfgno, "all");
 609                         kfree(bigbuffer);
 610                         goto err;
 611                 }
 612                 if (result < length) {
 613                         dev_warn(ddev, "config index %d descriptor too short "
 614                             "(expected %i, got %i)\n", cfgno, length, result);
 615                         length = result;
 616                 }
 617
 618                 dev->rawdescriptors[cfgno] = bigbuffer;
 619
 620                 result = usb_parse_configuration(dev, cfgno,
 621                     &dev->config[cfgno], bigbuffer, length);
 622                 if (result < 0) {
 623                         ++cfgno;
 624                         goto err;
 625                 }
 626         }
 627         result = 0;
 628
 629 err:
 630         kfree(desc);
 631         dev->descriptor.bNumConfigurations = cfgno;
 632 err2:
 633         if (result == -ENOMEM)
 634                 dev_err(ddev, "out of memory\n");
 635         return result;
 636 }