git.sur5r.net Git - u-boot/blob - drivers/usb/gadget/f_fastboot.c

   1 /*
   2  * (C) Copyright 2008 - 2009
   3  * Windriver, <www.windriver.com>
   4  * Tom Rix <Tom.Rix@windriver.com>
   5  *
   6  * Copyright 2011 Sebastian Andrzej Siewior <bigeasy@linutronix.de>
   7  *
   8  * Copyright 2014 Linaro, Ltd.
   9  * Rob Herring <robh@kernel.org>
  10  *
  11  * SPDX-License-Identifier:     GPL-2.0+
  12  */
  13 #include <config.h>
  14 #include <common.h>
  15 #include <errno.h>
  16 #include <malloc.h>
  17 #include <linux/usb/ch9.h>
  18 #include <linux/usb/gadget.h>
  19 #include <linux/usb/composite.h>
  20 #include <linux/compiler.h>
  21 #include <version.h>
  22 #include <g_dnl.h>
  23 #ifdef CONFIG_FASTBOOT_FLASH_MMC_DEV
  24 #include <fb_mmc.h>
  25 #endif
  26
  27 #define FASTBOOT_VERSION                "0.4"
  28
  29 #define FASTBOOT_INTERFACE_CLASS        0xff
  30 #define FASTBOOT_INTERFACE_SUB_CLASS    0x42
  31 #define FASTBOOT_INTERFACE_PROTOCOL     0x03
  32
  33 #define RX_ENDPOINT_MAXIMUM_PACKET_SIZE_2_0  (0x0200)
  34 #define RX_ENDPOINT_MAXIMUM_PACKET_SIZE_1_1  (0x0040)
  35 #define TX_ENDPOINT_MAXIMUM_PACKET_SIZE      (0x0040)
  36
  37 /* The 64 defined bytes plus \0 */
  38 #define RESPONSE_LEN    (64 + 1)
  39
  40 #define EP_BUFFER_SIZE                  4096
  41
  42 struct f_fastboot {
  43         struct usb_function usb_function;
  44
  45         /* IN/OUT EP's and corresponding requests */
  46         struct usb_ep *in_ep, *out_ep;
  47         struct usb_request *in_req, *out_req;
  48 };
  49
  50 static inline struct f_fastboot *func_to_fastboot(struct usb_function *f)
  51 {
  52         return container_of(f, struct f_fastboot, usb_function);
  53 }
  54
  55 static struct f_fastboot *fastboot_func;
  56 static unsigned int download_size;
  57 static unsigned int download_bytes;
  58 static bool is_high_speed;
  59
  60 static struct usb_endpoint_descriptor fs_ep_in = {
  61         .bLength            = USB_DT_ENDPOINT_SIZE,
  62         .bDescriptorType    = USB_DT_ENDPOINT,
  63         .bEndpointAddress   = USB_DIR_IN,
  64         .bmAttributes       = USB_ENDPOINT_XFER_BULK,
  65         .wMaxPacketSize     = TX_ENDPOINT_MAXIMUM_PACKET_SIZE,
  66         .bInterval          = 0x00,
  67 };
  68
  69 static struct usb_endpoint_descriptor fs_ep_out = {
  70         .bLength                = USB_DT_ENDPOINT_SIZE,
  71         .bDescriptorType        = USB_DT_ENDPOINT,
  72         .bEndpointAddress       = USB_DIR_OUT,
  73         .bmAttributes           = USB_ENDPOINT_XFER_BULK,
  74         .wMaxPacketSize         = RX_ENDPOINT_MAXIMUM_PACKET_SIZE_1_1,
  75         .bInterval              = 0x00,
  76 };
  77
  78 static struct usb_endpoint_descriptor hs_ep_out = {
  79         .bLength                = USB_DT_ENDPOINT_SIZE,
  80         .bDescriptorType        = USB_DT_ENDPOINT,
  81         .bEndpointAddress       = USB_DIR_OUT,
  82         .bmAttributes           = USB_ENDPOINT_XFER_BULK,
  83         .wMaxPacketSize         = RX_ENDPOINT_MAXIMUM_PACKET_SIZE_2_0,
  84         .bInterval              = 0x00,
  85 };
  86
  87 static struct usb_interface_descriptor interface_desc = {
  88         .bLength                = USB_DT_INTERFACE_SIZE,
  89         .bDescriptorType        = USB_DT_INTERFACE,
  90         .bInterfaceNumber       = 0x00,
  91         .bAlternateSetting      = 0x00,
  92         .bNumEndpoints          = 0x02,
  93         .bInterfaceClass        = FASTBOOT_INTERFACE_CLASS,
  94         .bInterfaceSubClass     = FASTBOOT_INTERFACE_SUB_CLASS,
  95         .bInterfaceProtocol     = FASTBOOT_INTERFACE_PROTOCOL,
  96 };
  97
  98 static struct usb_descriptor_header *fb_runtime_descs[] = {
  99         (struct usb_descriptor_header *)&interface_desc,
 100         (struct usb_descriptor_header *)&fs_ep_in,
 101         (struct usb_descriptor_header *)&hs_ep_out,
 102         NULL,
 103 };
 104
 105 /*
 106  * static strings, in UTF-8
 107  */
 108 static const char fastboot_name[] = "Android Fastboot";
 109
 110 static struct usb_string fastboot_string_defs[] = {
 111         [0].s = fastboot_name,
 112         {  }                    /* end of list */
 113 };
 114
 115 static struct usb_gadget_strings stringtab_fastboot = {
 116         .language       = 0x0409,       /* en-us */
 117         .strings        = fastboot_string_defs,
 118 };
 119
 120 static struct usb_gadget_strings *fastboot_strings[] = {
 121         &stringtab_fastboot,
 122         NULL,
 123 };
 124
 125 static void rx_handler_command(struct usb_ep *ep, struct usb_request *req);
 126
 127 static void fastboot_complete(struct usb_ep *ep, struct usb_request *req)
 128 {
 129         int status = req->status;
 130         if (!status)
 131                 return;
 132         printf("status: %d ep '%s' trans: %d\n", status, ep->name, req->actual);
 133 }
 134
 135 static int fastboot_bind(struct usb_configuration *c, struct usb_function *f)
 136 {
 137         int id;
 138         struct usb_gadget *gadget = c->cdev->gadget;
 139         struct f_fastboot *f_fb = func_to_fastboot(f);
 140         const char *s;
 141
 142         /* DYNAMIC interface numbers assignments */
 143         id = usb_interface_id(c, f);
 144         if (id < 0)
 145                 return id;
 146         interface_desc.bInterfaceNumber = id;
 147
 148         id = usb_string_id(c->cdev);
 149         if (id < 0)
 150                 return id;
 151         fastboot_string_defs[0].id = id;
 152         interface_desc.iInterface = id;
 153
 154         f_fb->in_ep = usb_ep_autoconfig(gadget, &fs_ep_in);
 155         if (!f_fb->in_ep)
 156                 return -ENODEV;
 157         f_fb->in_ep->driver_data = c->cdev;
 158
 159         f_fb->out_ep = usb_ep_autoconfig(gadget, &fs_ep_out);
 160         if (!f_fb->out_ep)
 161                 return -ENODEV;
 162         f_fb->out_ep->driver_data = c->cdev;
 163
 164         hs_ep_out.bEndpointAddress = fs_ep_out.bEndpointAddress;
 165
 166         s = getenv("serial#");
 167         if (s)
 168                 g_dnl_set_serialnumber((char *)s);
 169
 170         return 0;
 171 }
 172
 173 static void fastboot_unbind(struct usb_configuration *c, struct usb_function *f)
 174 {
 175         memset(fastboot_func, 0, sizeof(*fastboot_func));
 176 }
 177
 178 static void fastboot_disable(struct usb_function *f)
 179 {
 180         struct f_fastboot *f_fb = func_to_fastboot(f);
 181
 182         usb_ep_disable(f_fb->out_ep);
 183         usb_ep_disable(f_fb->in_ep);
 184
 185         if (f_fb->out_req) {
 186                 free(f_fb->out_req->buf);
 187                 usb_ep_free_request(f_fb->out_ep, f_fb->out_req);
 188                 f_fb->out_req = NULL;
 189         }
 190         if (f_fb->in_req) {
 191                 free(f_fb->in_req->buf);
 192                 usb_ep_free_request(f_fb->in_ep, f_fb->in_req);
 193                 f_fb->in_req = NULL;
 194         }
 195 }
 196
 197 static struct usb_request *fastboot_start_ep(struct usb_ep *ep)
 198 {
 199         struct usb_request *req;
 200
 201         req = usb_ep_alloc_request(ep, 0);
 202         if (!req)
 203                 return NULL;
 204
 205         req->length = EP_BUFFER_SIZE;
 206         req->buf = memalign(CONFIG_SYS_CACHELINE_SIZE, EP_BUFFER_SIZE);
 207         if (!req->buf) {
 208                 usb_ep_free_request(ep, req);
 209                 return NULL;
 210         }
 211
 212         memset(req->buf, 0, req->length);
 213         return req;
 214 }
 215
 216 static int fastboot_set_alt(struct usb_function *f,
 217                             unsigned interface, unsigned alt)
 218 {
 219         int ret;
 220         struct usb_composite_dev *cdev = f->config->cdev;
 221         struct usb_gadget *gadget = cdev->gadget;
 222         struct f_fastboot *f_fb = func_to_fastboot(f);
 223
 224         debug("%s: func: %s intf: %d alt: %d\n",
 225               __func__, f->name, interface, alt);
 226
 227         /* make sure we don't enable the ep twice */
 228         if (gadget->speed == USB_SPEED_HIGH) {
 229                 ret = usb_ep_enable(f_fb->out_ep, &hs_ep_out);
 230                 is_high_speed = true;
 231         } else {
 232                 ret = usb_ep_enable(f_fb->out_ep, &fs_ep_out);
 233                 is_high_speed = false;
 234         }
 235         if (ret) {
 236                 puts("failed to enable out ep\n");
 237                 return ret;
 238         }
 239
 240         f_fb->out_req = fastboot_start_ep(f_fb->out_ep);
 241         if (!f_fb->out_req) {
 242                 puts("failed to alloc out req\n");
 243                 ret = -EINVAL;
 244                 goto err;
 245         }
 246         f_fb->out_req->complete = rx_handler_command;
 247
 248         ret = usb_ep_enable(f_fb->in_ep, &fs_ep_in);
 249         if (ret) {
 250                 puts("failed to enable in ep\n");
 251                 goto err;
 252         }
 253
 254         f_fb->in_req = fastboot_start_ep(f_fb->in_ep);
 255         if (!f_fb->in_req) {
 256                 puts("failed alloc req in\n");
 257                 ret = -EINVAL;
 258                 goto err;
 259         }
 260         f_fb->in_req->complete = fastboot_complete;
 261
 262         ret = usb_ep_queue(f_fb->out_ep, f_fb->out_req, 0);
 263         if (ret)
 264                 goto err;
 265
 266         return 0;
 267 err:
 268         fastboot_disable(f);
 269         return ret;
 270 }
 271
 272 static int fastboot_add(struct usb_configuration *c)
 273 {
 274         struct f_fastboot *f_fb = fastboot_func;
 275         int status;
 276
 277         debug("%s: cdev: 0x%p\n", __func__, c->cdev);
 278
 279         if (!f_fb) {
 280                 f_fb = memalign(CONFIG_SYS_CACHELINE_SIZE, sizeof(*f_fb));
 281                 if (!f_fb)
 282                         return -ENOMEM;
 283
 284                 fastboot_func = f_fb;
 285                 memset(f_fb, 0, sizeof(*f_fb));
 286         }
 287
 288         f_fb->usb_function.name = "f_fastboot";
 289         f_fb->usb_function.hs_descriptors = fb_runtime_descs;
 290         f_fb->usb_function.bind = fastboot_bind;
 291         f_fb->usb_function.unbind = fastboot_unbind;
 292         f_fb->usb_function.set_alt = fastboot_set_alt;
 293         f_fb->usb_function.disable = fastboot_disable;
 294         f_fb->usb_function.strings = fastboot_strings;
 295
 296         status = usb_add_function(c, &f_fb->usb_function);
 297         if (status) {
 298                 free(f_fb);
 299                 fastboot_func = f_fb;
 300         }
 301
 302         return status;
 303 }
 304 DECLARE_GADGET_BIND_CALLBACK(usb_dnl_fastboot, fastboot_add);
 305
 306 static int fastboot_tx_write(const char *buffer, unsigned int buffer_size)
 307 {
 308         struct usb_request *in_req = fastboot_func->in_req;
 309         int ret;
 310
 311         memcpy(in_req->buf, buffer, buffer_size);
 312         in_req->length = buffer_size;
 313         ret = usb_ep_queue(fastboot_func->in_ep, in_req, 0);
 314         if (ret)
 315                 printf("Error %d on queue\n", ret);
 316         return 0;
 317 }
 318
 319 static int fastboot_tx_write_str(const char *buffer)
 320 {
 321         return fastboot_tx_write(buffer, strlen(buffer));
 322 }
 323
 324 static void compl_do_reset(struct usb_ep *ep, struct usb_request *req)
 325 {
 326         do_reset(NULL, 0, 0, NULL);
 327 }
 328
 329 static void cb_reboot(struct usb_ep *ep, struct usb_request *req)
 330 {
 331         fastboot_func->in_req->complete = compl_do_reset;
 332         fastboot_tx_write_str("OKAY");
 333 }
 334
 335 static int strcmp_l1(const char *s1, const char *s2)
 336 {
 337         if (!s1 || !s2)
 338                 return -1;
 339         return strncmp(s1, s2, strlen(s1));
 340 }
 341
 342 static void cb_getvar(struct usb_ep *ep, struct usb_request *req)
 343 {
 344         char *cmd = req->buf;
 345         char response[RESPONSE_LEN];
 346         const char *s;
 347         size_t chars_left;
 348
 349         strcpy(response, "OKAY");
 350         chars_left = sizeof(response) - strlen(response) - 1;
 351
 352         strsep(&cmd, ":");
 353         if (!cmd) {
 354                 error("missing variable\n");
 355                 fastboot_tx_write_str("FAILmissing var");
 356                 return;
 357         }
 358
 359         if (!strcmp_l1("version", cmd)) {
 360                 strncat(response, FASTBOOT_VERSION, chars_left);
 361         } else if (!strcmp_l1("bootloader-version", cmd)) {
 362                 strncat(response, U_BOOT_VERSION, chars_left);
 363         } else if (!strcmp_l1("downloadsize", cmd) ||
 364                 !strcmp_l1("max-download-size", cmd)) {
 365                 char str_num[12];
 366
 367                 sprintf(str_num, "0x%08x", CONFIG_USB_FASTBOOT_BUF_SIZE);
 368                 strncat(response, str_num, chars_left);
 369         } else if (!strcmp_l1("serialno", cmd)) {
 370                 s = getenv("serial#");
 371                 if (s)
 372                         strncat(response, s, chars_left);
 373                 else
 374                         strcpy(response, "FAILValue not set");
 375         } else {
 376                 error("unknown variable: %s\n", cmd);
 377                 strcpy(response, "FAILVariable not implemented");
 378         }
 379         fastboot_tx_write_str(response);
 380 }
 381
 382 static unsigned int rx_bytes_expected(unsigned int maxpacket)
 383 {
 384         int rx_remain = download_size - download_bytes;
 385         int rem = 0;
 386         if (rx_remain < 0)
 387                 return 0;
 388         if (rx_remain > EP_BUFFER_SIZE)
 389                 return EP_BUFFER_SIZE;
 390         if (rx_remain < maxpacket) {
 391                 rx_remain = maxpacket;
 392         } else if (rx_remain % maxpacket != 0) {
 393                 rem = rx_remain % maxpacket;
 394                 rx_remain = rx_remain + (maxpacket - rem);
 395         }
 396         return rx_remain;
 397 }
 398
 399 #define BYTES_PER_DOT   0x20000
 400 static void rx_handler_dl_image(struct usb_ep *ep, struct usb_request *req)
 401 {
 402         char response[RESPONSE_LEN];
 403         unsigned int transfer_size = download_size - download_bytes;
 404         const unsigned char *buffer = req->buf;
 405         unsigned int buffer_size = req->actual;
 406         unsigned int pre_dot_num, now_dot_num;
 407         unsigned int max;
 408
 409         if (req->status != 0) {
 410                 printf("Bad status: %d\n", req->status);
 411                 return;
 412         }
 413
 414         if (buffer_size < transfer_size)
 415                 transfer_size = buffer_size;
 416
 417         memcpy((void *)CONFIG_USB_FASTBOOT_BUF_ADDR + download_bytes,
 418                buffer, transfer_size);
 419
 420         pre_dot_num = download_bytes / BYTES_PER_DOT;
 421         download_bytes += transfer_size;
 422         now_dot_num = download_bytes / BYTES_PER_DOT;
 423
 424         if (pre_dot_num != now_dot_num) {
 425                 putc('.');
 426                 if (!(now_dot_num % 74))
 427                         putc('\n');
 428         }
 429
 430         /* Check if transfer is done */
 431         if (download_bytes >= download_size) {
 432                 /*
 433                  * Reset global transfer variable, keep download_bytes because
 434                  * it will be used in the next possible flashing command
 435                  */
 436                 download_size = 0;
 437                 req->complete = rx_handler_command;
 438                 req->length = EP_BUFFER_SIZE;
 439
 440                 sprintf(response, "OKAY");
 441                 fastboot_tx_write_str(response);
 442
 443                 printf("\ndownloading of %d bytes finished\n", download_bytes);
 444         } else {
 445                 max = is_high_speed ? hs_ep_out.wMaxPacketSize :
 446                                 fs_ep_out.wMaxPacketSize;
 447                 req->length = rx_bytes_expected(max);
 448                 if (req->length < ep->maxpacket)
 449                         req->length = ep->maxpacket;
 450         }
 451
 452         req->actual = 0;
 453         usb_ep_queue(ep, req, 0);
 454 }
 455
 456 static void cb_download(struct usb_ep *ep, struct usb_request *req)
 457 {
 458         char *cmd = req->buf;
 459         char response[RESPONSE_LEN];
 460         unsigned int max;
 461
 462         strsep(&cmd, ":");
 463         download_size = simple_strtoul(cmd, NULL, 16);
 464         download_bytes = 0;
 465
 466         printf("Starting download of %d bytes\n", download_size);
 467
 468         if (0 == download_size) {
 469                 sprintf(response, "FAILdata invalid size");
 470         } else if (download_size > CONFIG_USB_FASTBOOT_BUF_SIZE) {
 471                 download_size = 0;
 472                 sprintf(response, "FAILdata too large");
 473         } else {
 474                 sprintf(response, "DATA%08x", download_size);
 475                 req->complete = rx_handler_dl_image;
 476                 max = is_high_speed ? hs_ep_out.wMaxPacketSize :
 477                         fs_ep_out.wMaxPacketSize;
 478                 req->length = rx_bytes_expected(max);
 479                 if (req->length < ep->maxpacket)
 480                         req->length = ep->maxpacket;
 481         }
 482         fastboot_tx_write_str(response);
 483 }
 484
 485 static void do_bootm_on_complete(struct usb_ep *ep, struct usb_request *req)
 486 {
 487         char boot_addr_start[12];
 488         char *bootm_args[] = { "bootm", boot_addr_start, NULL };
 489
 490         puts("Booting kernel..\n");
 491
 492         sprintf(boot_addr_start, "0x%lx", load_addr);
 493         do_bootm(NULL, 0, 2, bootm_args);
 494
 495         /* This only happens if image is somehow faulty so we start over */
 496         do_reset(NULL, 0, 0, NULL);
 497 }
 498
 499 static void cb_boot(struct usb_ep *ep, struct usb_request *req)
 500 {
 501         fastboot_func->in_req->complete = do_bootm_on_complete;
 502         fastboot_tx_write_str("OKAY");
 503 }
 504
 505 static void do_exit_on_complete(struct usb_ep *ep, struct usb_request *req)
 506 {
 507         g_dnl_trigger_detach();
 508 }
 509
 510 static void cb_continue(struct usb_ep *ep, struct usb_request *req)
 511 {
 512         fastboot_func->in_req->complete = do_exit_on_complete;
 513         fastboot_tx_write_str("OKAY");
 514 }
 515
 516 #ifdef CONFIG_FASTBOOT_FLASH
 517 static void cb_flash(struct usb_ep *ep, struct usb_request *req)
 518 {
 519         char *cmd = req->buf;
 520         char response[RESPONSE_LEN];
 521
 522         strsep(&cmd, ":");
 523         if (!cmd) {
 524                 error("missing partition name\n");
 525                 fastboot_tx_write_str("FAILmissing partition name");
 526                 return;
 527         }
 528
 529         strcpy(response, "FAILno flash device defined");
 530 #ifdef CONFIG_FASTBOOT_FLASH_MMC_DEV
 531         fb_mmc_flash_write(cmd, (void *)CONFIG_USB_FASTBOOT_BUF_ADDR,
 532                            download_bytes, response);
 533 #endif
 534         fastboot_tx_write_str(response);
 535 }
 536 #endif
 537
 538 static void cb_oem(struct usb_ep *ep, struct usb_request *req)
 539 {
 540         char *cmd = req->buf;
 541 #ifdef CONFIG_FASTBOOT_FLASH
 542         if (strncmp("format", cmd + 4, 6) == 0) {
 543                 char cmdbuf[32];
 544                 sprintf(cmdbuf, "gpt write mmc %x $partitions",
 545                         CONFIG_FASTBOOT_FLASH_MMC_DEV);
 546                 if (run_command(cmdbuf, 0))
 547                         fastboot_tx_write_str("FAIL");
 548                 else
 549                         fastboot_tx_write_str("OKAY");
 550         } else
 551 #endif
 552         if (strncmp("unlock", cmd + 4, 8) == 0) {
 553                 fastboot_tx_write_str("FAILnot implemented");
 554         }
 555         else {
 556                 fastboot_tx_write_str("FAILunknown oem command");
 557         }
 558 }
 559
 560 #ifdef CONFIG_FASTBOOT_FLASH
 561 static void cb_erase(struct usb_ep *ep, struct usb_request *req)
 562 {
 563         char *cmd = req->buf;
 564         char response[RESPONSE_LEN];
 565
 566         strsep(&cmd, ":");
 567         if (!cmd) {
 568                 error("missing partition name");
 569                 fastboot_tx_write_str("FAILmissing partition name");
 570                 return;
 571         }
 572
 573         strcpy(response, "FAILno flash device defined");
 574
 575 #ifdef CONFIG_FASTBOOT_FLASH_MMC_DEV
 576         fb_mmc_erase(cmd, response);
 577 #endif
 578         fastboot_tx_write_str(response);
 579 }
 580 #endif
 581
 582 struct cmd_dispatch_info {
 583         char *cmd;
 584         void (*cb)(struct usb_ep *ep, struct usb_request *req);
 585 };
 586
 587 static const struct cmd_dispatch_info cmd_dispatch_info[] = {
 588         {
 589                 .cmd = "reboot",
 590                 .cb = cb_reboot,
 591         }, {
 592                 .cmd = "getvar:",
 593                 .cb = cb_getvar,
 594         }, {
 595                 .cmd = "download:",
 596                 .cb = cb_download,
 597         }, {
 598                 .cmd = "boot",
 599                 .cb = cb_boot,
 600         }, {
 601                 .cmd = "continue",
 602                 .cb = cb_continue,
 603         },
 604 #ifdef CONFIG_FASTBOOT_FLASH
 605         {
 606                 .cmd = "flash",
 607                 .cb = cb_flash,
 608         }, {
 609                 .cmd = "erase",
 610                 .cb = cb_erase,
 611         },
 612 #endif
 613         {
 614                 .cmd = "oem",
 615                 .cb = cb_oem,
 616         },
 617 };
 618
 619 static void rx_handler_command(struct usb_ep *ep, struct usb_request *req)
 620 {
 621         char *cmdbuf = req->buf;
 622         void (*func_cb)(struct usb_ep *ep, struct usb_request *req) = NULL;
 623         int i;
 624
 625         for (i = 0; i < ARRAY_SIZE(cmd_dispatch_info); i++) {
 626                 if (!strcmp_l1(cmd_dispatch_info[i].cmd, cmdbuf)) {
 627                         func_cb = cmd_dispatch_info[i].cb;
 628                         break;
 629                 }
 630         }
 631
 632         if (!func_cb) {
 633                 error("unknown command: %s\n", cmdbuf);
 634                 fastboot_tx_write_str("FAILunknown command");
 635         } else {
 636                 if (req->actual < req->length) {
 637                         u8 *buf = (u8 *)req->buf;
 638                         buf[req->actual] = 0;
 639                         func_cb(ep, req);
 640                 } else {
 641                         error("buffer overflow\n");
 642                         fastboot_tx_write_str("FAILbuffer overflow");
 643                 }
 644         }
 645
 646         if (req->status == 0) {
 647                 *cmdbuf = '\0';
 648                 req->actual = 0;
 649                 usb_ep_queue(ep, req, 0);
 650         }
 651 }