1 /* 2 * uvc_video.c -- USB Video Class driver - Video handling 3 * 4 * Copyright (C) 2005-2010 5 * Laurent Pinchart (laurent.pinchart@ideasonboard.com) 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License as published by 9 * the Free Software Foundation; either version 2 of the License, or 10 * (at your option) any later version. 11 * 12 */ 13 14 #include <linux/kernel.h> 15 #include <linux/list.h> 16 #include <linux/module.h> 17 #include <linux/slab.h> 18 #include <linux/usb.h> 19 #include <linux/videodev2.h> 20 #include <linux/vmalloc.h> 21 #include <linux/wait.h> 22 #include <linux/atomic.h> 23 #include <asm/unaligned.h> 24 25 #include <media/v4l2-common.h> 26 27 #include "uvcvideo.h" 28 29 /* ------------------------------------------------------------------------ 30 * UVC Controls 31 */ 32 33 static int __uvc_query_ctrl(struct uvc_device *dev, __u8 query, __u8 unit, 34 __u8 intfnum, __u8 cs, void *data, __u16 size, 35 int timeout) 36 { 37 __u8 type = USB_TYPE_CLASS | USB_RECIP_INTERFACE; 38 unsigned int pipe; 39 40 pipe = (query & 0x80) ? usb_rcvctrlpipe(dev->udev, 0) 41 : usb_sndctrlpipe(dev->udev, 0); 42 type |= (query & 0x80) ? USB_DIR_IN : USB_DIR_OUT; 43 44 return usb_control_msg(dev->udev, pipe, query, type, cs << 8, 45 unit << 8 | intfnum, data, size, timeout); 46 } 47 48 static const char *uvc_query_name(__u8 query) 49 { 50 switch (query) { 51 case UVC_SET_CUR: 52 return "SET_CUR"; 53 case UVC_GET_CUR: 54 return "GET_CUR"; 55 case UVC_GET_MIN: 56 return "GET_MIN"; 57 case UVC_GET_MAX: 58 return "GET_MAX"; 59 case UVC_GET_RES: 60 return "GET_RES"; 61 case UVC_GET_LEN: 62 return "GET_LEN"; 63 case UVC_GET_INFO: 64 return "GET_INFO"; 65 case UVC_GET_DEF: 66 return "GET_DEF"; 67 default: 68 return "<invalid>"; 69 } 70 } 71 72 int uvc_query_ctrl(struct uvc_device *dev, __u8 query, __u8 unit, 73 __u8 intfnum, __u8 cs, void *data, __u16 size) 74 { 75 int ret; 76 77 ret = __uvc_query_ctrl(dev, query, unit, intfnum, cs, data, size, 78 UVC_CTRL_CONTROL_TIMEOUT); 79 if (ret != size) { 80 uvc_printk(KERN_ERR, "Failed to query (%s) UVC control %u on " 81 "unit %u: %d (exp. %u).\n", uvc_query_name(query), cs, 82 unit, ret, size); 83 return -EIO; 84 } 85 86 return 0; 87 } 88 89 static void uvc_fixup_video_ctrl(struct uvc_streaming *stream, 90 struct uvc_streaming_control *ctrl) 91 { 92 struct uvc_format *format = NULL; 93 struct uvc_frame *frame = NULL; 94 unsigned int i; 95 96 for (i = 0; i < stream->nformats; ++i) { 97 if (stream->format[i].index == ctrl->bFormatIndex) { 98 format = &stream->format[i]; 99 break; 100 } 101 } 102 103 if (format == NULL) 104 return; 105 106 for (i = 0; i < format->nframes; ++i) { 107 if (format->frame[i].bFrameIndex == ctrl->bFrameIndex) { 108 frame = &format->frame[i]; 109 break; 110 } 111 } 112 113 if (frame == NULL) 114 return; 115 116 if (!(format->flags & UVC_FMT_FLAG_COMPRESSED) || 117 (ctrl->dwMaxVideoFrameSize == 0 && 118 stream->dev->uvc_version < 0x0110)) 119 ctrl->dwMaxVideoFrameSize = 120 frame->dwMaxVideoFrameBufferSize; 121 122 if (!(format->flags & UVC_FMT_FLAG_COMPRESSED) && 123 stream->dev->quirks & UVC_QUIRK_FIX_BANDWIDTH && 124 stream->intf->num_altsetting > 1) { 125 u32 interval; 126 u32 bandwidth; 127 128 interval = (ctrl->dwFrameInterval > 100000) 129 ? ctrl->dwFrameInterval 130 : frame->dwFrameInterval[0]; 131 132 /* Compute a bandwidth estimation by multiplying the frame 133 * size by the number of video frames per second, divide the 134 * result by the number of USB frames (or micro-frames for 135 * high-speed devices) per second and add the UVC header size 136 * (assumed to be 12 bytes long). 137 */ 138 bandwidth = frame->wWidth * frame->wHeight / 8 * format->bpp; 139 bandwidth *= 10000000 / interval + 1; 140 bandwidth /= 1000; 141 if (stream->dev->udev->speed == USB_SPEED_HIGH) 142 bandwidth /= 8; 143 bandwidth += 12; 144 145 /* The bandwidth estimate is too low for many cameras. Don't use 146 * maximum packet sizes lower than 1024 bytes to try and work 147 * around the problem. According to measurements done on two 148 * different camera models, the value is high enough to get most 149 * resolutions working while not preventing two simultaneous 150 * VGA streams at 15 fps. 151 */ 152 bandwidth = max_t(u32, bandwidth, 1024); 153 154 ctrl->dwMaxPayloadTransferSize = bandwidth; 155 } 156 } 157 158 static int uvc_get_video_ctrl(struct uvc_streaming *stream, 159 struct uvc_streaming_control *ctrl, int probe, __u8 query) 160 { 161 __u8 *data; 162 __u16 size; 163 int ret; 164 165 size = stream->dev->uvc_version >= 0x0110 ? 34 : 26; 166 if ((stream->dev->quirks & UVC_QUIRK_PROBE_DEF) && 167 query == UVC_GET_DEF) 168 return -EIO; 169 170 data = kmalloc(size, GFP_KERNEL); 171 if (data == NULL) 172 return -ENOMEM; 173 174 ret = __uvc_query_ctrl(stream->dev, query, 0, stream->intfnum, 175 probe ? UVC_VS_PROBE_CONTROL : UVC_VS_COMMIT_CONTROL, data, 176 size, uvc_timeout_param); 177 178 if ((query == UVC_GET_MIN || query == UVC_GET_MAX) && ret == 2) { 179 /* Some cameras, mostly based on Bison Electronics chipsets, 180 * answer a GET_MIN or GET_MAX request with the wCompQuality 181 * field only. 182 */ 183 uvc_warn_once(stream->dev, UVC_WARN_MINMAX, "UVC non " 184 "compliance - GET_MIN/MAX(PROBE) incorrectly " 185 "supported. Enabling workaround.\n"); 186 memset(ctrl, 0, sizeof *ctrl); 187 ctrl->wCompQuality = le16_to_cpup((__le16 *)data); 188 ret = 0; 189 goto out; 190 } else if (query == UVC_GET_DEF && probe == 1 && ret != size) { 191 /* Many cameras don't support the GET_DEF request on their 192 * video probe control. Warn once and return, the caller will 193 * fall back to GET_CUR. 194 */ 195 uvc_warn_once(stream->dev, UVC_WARN_PROBE_DEF, "UVC non " 196 "compliance - GET_DEF(PROBE) not supported. " 197 "Enabling workaround.\n"); 198 ret = -EIO; 199 goto out; 200 } else if (ret != size) { 201 uvc_printk(KERN_ERR, "Failed to query (%u) UVC %s control : " 202 "%d (exp. %u).\n", query, probe ? "probe" : "commit", 203 ret, size); 204 ret = -EIO; 205 goto out; 206 } 207 208 ctrl->bmHint = le16_to_cpup((__le16 *)&data[0]); 209 ctrl->bFormatIndex = data[2]; 210 ctrl->bFrameIndex = data[3]; 211 ctrl->dwFrameInterval = le32_to_cpup((__le32 *)&data[4]); 212 ctrl->wKeyFrameRate = le16_to_cpup((__le16 *)&data[8]); 213 ctrl->wPFrameRate = le16_to_cpup((__le16 *)&data[10]); 214 ctrl->wCompQuality = le16_to_cpup((__le16 *)&data[12]); 215 ctrl->wCompWindowSize = le16_to_cpup((__le16 *)&data[14]); 216 ctrl->wDelay = le16_to_cpup((__le16 *)&data[16]); 217 ctrl->dwMaxVideoFrameSize = get_unaligned_le32(&data[18]); 218 ctrl->dwMaxPayloadTransferSize = get_unaligned_le32(&data[22]); 219 220 if (size == 34) { 221 ctrl->dwClockFrequency = get_unaligned_le32(&data[26]); 222 ctrl->bmFramingInfo = data[30]; 223 ctrl->bPreferedVersion = data[31]; 224 ctrl->bMinVersion = data[32]; 225 ctrl->bMaxVersion = data[33]; 226 } else { 227 ctrl->dwClockFrequency = stream->dev->clock_frequency; 228 ctrl->bmFramingInfo = 0; 229 ctrl->bPreferedVersion = 0; 230 ctrl->bMinVersion = 0; 231 ctrl->bMaxVersion = 0; 232 } 233 234 /* Some broken devices return null or wrong dwMaxVideoFrameSize and 235 * dwMaxPayloadTransferSize fields. Try to get the value from the 236 * format and frame descriptors. 237 */ 238 uvc_fixup_video_ctrl(stream, ctrl); 239 ret = 0; 240 241 out: 242 kfree(data); 243 return ret; 244 } 245 246 static int uvc_set_video_ctrl(struct uvc_streaming *stream, 247 struct uvc_streaming_control *ctrl, int probe) 248 { 249 __u8 *data; 250 __u16 size; 251 int ret; 252 253 size = stream->dev->uvc_version >= 0x0110 ? 34 : 26; 254 data = kzalloc(size, GFP_KERNEL); 255 if (data == NULL) 256 return -ENOMEM; 257 258 *(__le16 *)&data[0] = cpu_to_le16(ctrl->bmHint); 259 data[2] = ctrl->bFormatIndex; 260 data[3] = ctrl->bFrameIndex; 261 *(__le32 *)&data[4] = cpu_to_le32(ctrl->dwFrameInterval); 262 *(__le16 *)&data[8] = cpu_to_le16(ctrl->wKeyFrameRate); 263 *(__le16 *)&data[10] = cpu_to_le16(ctrl->wPFrameRate); 264 *(__le16 *)&data[12] = cpu_to_le16(ctrl->wCompQuality); 265 *(__le16 *)&data[14] = cpu_to_le16(ctrl->wCompWindowSize); 266 *(__le16 *)&data[16] = cpu_to_le16(ctrl->wDelay); 267 put_unaligned_le32(ctrl->dwMaxVideoFrameSize, &data[18]); 268 put_unaligned_le32(ctrl->dwMaxPayloadTransferSize, &data[22]); 269 270 if (size == 34) { 271 put_unaligned_le32(ctrl->dwClockFrequency, &data[26]); 272 data[30] = ctrl->bmFramingInfo; 273 data[31] = ctrl->bPreferedVersion; 274 data[32] = ctrl->bMinVersion; 275 data[33] = ctrl->bMaxVersion; 276 } 277 278 ret = __uvc_query_ctrl(stream->dev, UVC_SET_CUR, 0, stream->intfnum, 279 probe ? UVC_VS_PROBE_CONTROL : UVC_VS_COMMIT_CONTROL, data, 280 size, uvc_timeout_param); 281 if (ret != size) { 282 uvc_printk(KERN_ERR, "Failed to set UVC %s control : " 283 "%d (exp. %u).\n", probe ? "probe" : "commit", 284 ret, size); 285 ret = -EIO; 286 } 287 288 kfree(data); 289 return ret; 290 } 291 292 int uvc_probe_video(struct uvc_streaming *stream, 293 struct uvc_streaming_control *probe) 294 { 295 struct uvc_streaming_control probe_min, probe_max; 296 __u16 bandwidth; 297 unsigned int i; 298 int ret; 299 300 /* Perform probing. The device should adjust the requested values 301 * according to its capabilities. However, some devices, namely the 302 * first generation UVC Logitech webcams, don't implement the Video 303 * Probe control properly, and just return the needed bandwidth. For 304 * that reason, if the needed bandwidth exceeds the maximum available 305 * bandwidth, try to lower the quality. 306 */ 307 ret = uvc_set_video_ctrl(stream, probe, 1); 308 if (ret < 0) 309 goto done; 310 311 /* Get the minimum and maximum values for compression settings. */ 312 if (!(stream->dev->quirks & UVC_QUIRK_PROBE_MINMAX)) { 313 ret = uvc_get_video_ctrl(stream, &probe_min, 1, UVC_GET_MIN); 314 if (ret < 0) 315 goto done; 316 ret = uvc_get_video_ctrl(stream, &probe_max, 1, UVC_GET_MAX); 317 if (ret < 0) 318 goto done; 319 320 probe->wCompQuality = probe_max.wCompQuality; 321 } 322 323 for (i = 0; i < 2; ++i) { 324 ret = uvc_set_video_ctrl(stream, probe, 1); 325 if (ret < 0) 326 goto done; 327 ret = uvc_get_video_ctrl(stream, probe, 1, UVC_GET_CUR); 328 if (ret < 0) 329 goto done; 330 331 if (stream->intf->num_altsetting == 1) 332 break; 333 334 bandwidth = probe->dwMaxPayloadTransferSize; 335 if (bandwidth <= stream->maxpsize) 336 break; 337 338 if (stream->dev->quirks & UVC_QUIRK_PROBE_MINMAX) { 339 ret = -ENOSPC; 340 goto done; 341 } 342 343 /* TODO: negotiate compression parameters */ 344 probe->wKeyFrameRate = probe_min.wKeyFrameRate; 345 probe->wPFrameRate = probe_min.wPFrameRate; 346 probe->wCompQuality = probe_max.wCompQuality; 347 probe->wCompWindowSize = probe_min.wCompWindowSize; 348 } 349 350 done: 351 return ret; 352 } 353 354 static int uvc_commit_video(struct uvc_streaming *stream, 355 struct uvc_streaming_control *probe) 356 { 357 return uvc_set_video_ctrl(stream, probe, 0); 358 } 359 360 /* ----------------------------------------------------------------------------- 361 * Clocks and timestamps 362 */ 363 364 static inline void uvc_video_get_ts(struct timespec *ts) 365 { 366 if (uvc_clock_param == CLOCK_MONOTONIC) 367 ktime_get_ts(ts); 368 else 369 ktime_get_real_ts(ts); 370 } 371 372 static void 373 uvc_video_clock_decode(struct uvc_streaming *stream, struct uvc_buffer *buf, 374 const __u8 *data, int len) 375 { 376 struct uvc_clock_sample *sample; 377 unsigned int header_size; 378 bool has_pts = false; 379 bool has_scr = false; 380 unsigned long flags; 381 struct timespec ts; 382 u16 host_sof; 383 u16 dev_sof; 384 385 switch (data[1] & (UVC_STREAM_PTS | UVC_STREAM_SCR)) { 386 case UVC_STREAM_PTS | UVC_STREAM_SCR: 387 header_size = 12; 388 has_pts = true; 389 has_scr = true; 390 break; 391 case UVC_STREAM_PTS: 392 header_size = 6; 393 has_pts = true; 394 break; 395 case UVC_STREAM_SCR: 396 header_size = 8; 397 has_scr = true; 398 break; 399 default: 400 header_size = 2; 401 break; 402 } 403 404 /* Check for invalid headers. */ 405 if (len < header_size) 406 return; 407 408 /* Extract the timestamps: 409 * 410 * - store the frame PTS in the buffer structure 411 * - if the SCR field is present, retrieve the host SOF counter and 412 * kernel timestamps and store them with the SCR STC and SOF fields 413 * in the ring buffer 414 */ 415 if (has_pts && buf != NULL) 416 buf->pts = get_unaligned_le32(&data[2]); 417 418 if (!has_scr) 419 return; 420 421 /* To limit the amount of data, drop SCRs with an SOF identical to the 422 * previous one. 423 */ 424 dev_sof = get_unaligned_le16(&data[header_size - 2]); 425 if (dev_sof == stream->clock.last_sof) 426 return; 427 428 stream->clock.last_sof = dev_sof; 429 430 host_sof = usb_get_current_frame_number(stream->dev->udev); 431 uvc_video_get_ts(&ts); 432 433 /* The UVC specification allows device implementations that can't obtain 434 * the USB frame number to keep their own frame counters as long as they 435 * match the size and frequency of the frame number associated with USB 436 * SOF tokens. The SOF values sent by such devices differ from the USB 437 * SOF tokens by a fixed offset that needs to be estimated and accounted 438 * for to make timestamp recovery as accurate as possible. 439 * 440 * The offset is estimated the first time a device SOF value is received 441 * as the difference between the host and device SOF values. As the two 442 * SOF values can differ slightly due to transmission delays, consider 443 * that the offset is null if the difference is not higher than 10 ms 444 * (negative differences can not happen and are thus considered as an 445 * offset). The video commit control wDelay field should be used to 446 * compute a dynamic threshold instead of using a fixed 10 ms value, but 447 * devices don't report reliable wDelay values. 448 * 449 * See uvc_video_clock_host_sof() for an explanation regarding why only 450 * the 8 LSBs of the delta are kept. 451 */ 452 if (stream->clock.sof_offset == (u16)-1) { 453 u16 delta_sof = (host_sof - dev_sof) & 255; 454 if (delta_sof >= 10) 455 stream->clock.sof_offset = delta_sof; 456 else 457 stream->clock.sof_offset = 0; 458 } 459 460 dev_sof = (dev_sof + stream->clock.sof_offset) & 2047; 461 462 spin_lock_irqsave(&stream->clock.lock, flags); 463 464 sample = &stream->clock.samples[stream->clock.head]; 465 sample->dev_stc = get_unaligned_le32(&data[header_size - 6]); 466 sample->dev_sof = dev_sof; 467 sample->host_sof = host_sof; 468 sample->host_ts = ts; 469 470 /* Update the sliding window head and count. */ 471 stream->clock.head = (stream->clock.head + 1) % stream->clock.size; 472 473 if (stream->clock.count < stream->clock.size) 474 stream->clock.count++; 475 476 spin_unlock_irqrestore(&stream->clock.lock, flags); 477 } 478 479 static void uvc_video_clock_reset(struct uvc_streaming *stream) 480 { 481 struct uvc_clock *clock = &stream->clock; 482 483 clock->head = 0; 484 clock->count = 0; 485 clock->last_sof = -1; 486 clock->sof_offset = -1; 487 } 488 489 static int uvc_video_clock_init(struct uvc_streaming *stream) 490 { 491 struct uvc_clock *clock = &stream->clock; 492 493 spin_lock_init(&clock->lock); 494 clock->size = 32; 495 496 clock->samples = kmalloc(clock->size * sizeof(*clock->samples), 497 GFP_KERNEL); 498 if (clock->samples == NULL) 499 return -ENOMEM; 500 501 uvc_video_clock_reset(stream); 502 503 return 0; 504 } 505 506 static void uvc_video_clock_cleanup(struct uvc_streaming *stream) 507 { 508 kfree(stream->clock.samples); 509 stream->clock.samples = NULL; 510 } 511 512 /* 513 * uvc_video_clock_host_sof - Return the host SOF value for a clock sample 514 * 515 * Host SOF counters reported by usb_get_current_frame_number() usually don't 516 * cover the whole 11-bits SOF range (0-2047) but are limited to the HCI frame 517 * schedule window. They can be limited to 8, 9 or 10 bits depending on the host 518 * controller and its configuration. 519 * 520 * We thus need to recover the SOF value corresponding to the host frame number. 521 * As the device and host frame numbers are sampled in a short interval, the 522 * difference between their values should be equal to a small delta plus an 523 * integer multiple of 256 caused by the host frame number limited precision. 524 * 525 * To obtain the recovered host SOF value, compute the small delta by masking 526 * the high bits of the host frame counter and device SOF difference and add it 527 * to the device SOF value. 528 */ 529 static u16 uvc_video_clock_host_sof(const struct uvc_clock_sample *sample) 530 { 531 /* The delta value can be negative. */ 532 s8 delta_sof; 533 534 delta_sof = (sample->host_sof - sample->dev_sof) & 255; 535 536 return (sample->dev_sof + delta_sof) & 2047; 537 } 538 539 /* 540 * uvc_video_clock_update - Update the buffer timestamp 541 * 542 * This function converts the buffer PTS timestamp to the host clock domain by 543 * going through the USB SOF clock domain and stores the result in the V4L2 544 * buffer timestamp field. 545 * 546 * The relationship between the device clock and the host clock isn't known. 547 * However, the device and the host share the common USB SOF clock which can be 548 * used to recover that relationship. 549 * 550 * The relationship between the device clock and the USB SOF clock is considered 551 * to be linear over the clock samples sliding window and is given by 552 * 553 * SOF = m * PTS + p 554 * 555 * Several methods to compute the slope (m) and intercept (p) can be used. As 556 * the clock drift should be small compared to the sliding window size, we 557 * assume that the line that goes through the points at both ends of the window 558 * is a good approximation. Naming those points P1 and P2, we get 559 * 560 * SOF = (SOF2 - SOF1) / (STC2 - STC1) * PTS 561 * + (SOF1 * STC2 - SOF2 * STC1) / (STC2 - STC1) 562 * 563 * or 564 * 565 * SOF = ((SOF2 - SOF1) * PTS + SOF1 * STC2 - SOF2 * STC1) / (STC2 - STC1) (1) 566 * 567 * to avoid losing precision in the division. Similarly, the host timestamp is 568 * computed with 569 * 570 * TS = ((TS2 - TS1) * PTS + TS1 * SOF2 - TS2 * SOF1) / (SOF2 - SOF1) (2) 571 * 572 * SOF values are coded on 11 bits by USB. We extend their precision with 16 573 * decimal bits, leading to a 11.16 coding. 574 * 575 * TODO: To avoid surprises with device clock values, PTS/STC timestamps should 576 * be normalized using the nominal device clock frequency reported through the 577 * UVC descriptors. 578 * 579 * Both the PTS/STC and SOF counters roll over, after a fixed but device 580 * specific amount of time for PTS/STC and after 2048ms for SOF. As long as the 581 * sliding window size is smaller than the rollover period, differences computed 582 * on unsigned integers will produce the correct result. However, the p term in 583 * the linear relations will be miscomputed. 584 * 585 * To fix the issue, we subtract a constant from the PTS and STC values to bring 586 * PTS to half the 32 bit STC range. The sliding window STC values then fit into 587 * the 32 bit range without any rollover. 588 * 589 * Similarly, we add 2048 to the device SOF values to make sure that the SOF 590 * computed by (1) will never be smaller than 0. This offset is then compensated 591 * by adding 2048 to the SOF values used in (2). However, this doesn't prevent 592 * rollovers between (1) and (2): the SOF value computed by (1) can be slightly 593 * lower than 4096, and the host SOF counters can have rolled over to 2048. This 594 * case is handled by subtracting 2048 from the SOF value if it exceeds the host 595 * SOF value at the end of the sliding window. 596 * 597 * Finally we subtract a constant from the host timestamps to bring the first 598 * timestamp of the sliding window to 1s. 599 */ 600 void uvc_video_clock_update(struct uvc_streaming *stream, 601 struct v4l2_buffer *v4l2_buf, 602 struct uvc_buffer *buf) 603 { 604 struct uvc_clock *clock = &stream->clock; 605 struct uvc_clock_sample *first; 606 struct uvc_clock_sample *last; 607 unsigned long flags; 608 struct timespec ts; 609 u32 delta_stc; 610 u32 y1, y2; 611 u32 x1, x2; 612 u32 mean; 613 u32 sof; 614 u32 div; 615 u32 rem; 616 u64 y; 617 618 spin_lock_irqsave(&clock->lock, flags); 619 620 if (clock->count < clock->size) 621 goto done; 622 623 first = &clock->samples[clock->head]; 624 last = &clock->samples[(clock->head - 1) % clock->size]; 625 626 /* First step, PTS to SOF conversion. */ 627 delta_stc = buf->pts - (1UL << 31); 628 x1 = first->dev_stc - delta_stc; 629 x2 = last->dev_stc - delta_stc; 630 if (x1 == x2) 631 goto done; 632 633 y1 = (first->dev_sof + 2048) << 16; 634 y2 = (last->dev_sof + 2048) << 16; 635 if (y2 < y1) 636 y2 += 2048 << 16; 637 638 y = (u64)(y2 - y1) * (1ULL << 31) + (u64)y1 * (u64)x2 639 - (u64)y2 * (u64)x1; 640 y = div_u64(y, x2 - x1); 641 642 sof = y; 643 644 uvc_trace(UVC_TRACE_CLOCK, "%s: PTS %u y %llu.%06llu SOF %u.%06llu " 645 "(x1 %u x2 %u y1 %u y2 %u SOF offset %u)\n", 646 stream->dev->name, buf->pts, 647 y >> 16, div_u64((y & 0xffff) * 1000000, 65536), 648 sof >> 16, div_u64(((u64)sof & 0xffff) * 1000000LLU, 65536), 649 x1, x2, y1, y2, clock->sof_offset); 650 651 /* Second step, SOF to host clock conversion. */ 652 x1 = (uvc_video_clock_host_sof(first) + 2048) << 16; 653 x2 = (uvc_video_clock_host_sof(last) + 2048) << 16; 654 if (x2 < x1) 655 x2 += 2048 << 16; 656 if (x1 == x2) 657 goto done; 658 659 ts = timespec_sub(last->host_ts, first->host_ts); 660 y1 = NSEC_PER_SEC; 661 y2 = (ts.tv_sec + 1) * NSEC_PER_SEC + ts.tv_nsec; 662 663 /* Interpolated and host SOF timestamps can wrap around at slightly 664 * different times. Handle this by adding or removing 2048 to or from 665 * the computed SOF value to keep it close to the SOF samples mean 666 * value. 667 */ 668 mean = (x1 + x2) / 2; 669 if (mean - (1024 << 16) > sof) 670 sof += 2048 << 16; 671 else if (sof > mean + (1024 << 16)) 672 sof -= 2048 << 16; 673 674 y = (u64)(y2 - y1) * (u64)sof + (u64)y1 * (u64)x2 675 - (u64)y2 * (u64)x1; 676 y = div_u64(y, x2 - x1); 677 678 div = div_u64_rem(y, NSEC_PER_SEC, &rem); 679 ts.tv_sec = first->host_ts.tv_sec - 1 + div; 680 ts.tv_nsec = first->host_ts.tv_nsec + rem; 681 if (ts.tv_nsec >= NSEC_PER_SEC) { 682 ts.tv_sec++; 683 ts.tv_nsec -= NSEC_PER_SEC; 684 } 685 686 uvc_trace(UVC_TRACE_CLOCK, "%s: SOF %u.%06llu y %llu ts %lu.%06lu " 687 "buf ts %lu.%06lu (x1 %u/%u/%u x2 %u/%u/%u y1 %u y2 %u)\n", 688 stream->dev->name, 689 sof >> 16, div_u64(((u64)sof & 0xffff) * 1000000LLU, 65536), 690 y, ts.tv_sec, ts.tv_nsec / NSEC_PER_USEC, 691 v4l2_buf->timestamp.tv_sec, 692 (unsigned long)v4l2_buf->timestamp.tv_usec, 693 x1, first->host_sof, first->dev_sof, 694 x2, last->host_sof, last->dev_sof, y1, y2); 695 696 /* Update the V4L2 buffer. */ 697 v4l2_buf->timestamp.tv_sec = ts.tv_sec; 698 v4l2_buf->timestamp.tv_usec = ts.tv_nsec / NSEC_PER_USEC; 699 700 done: 701 spin_unlock_irqrestore(&stream->clock.lock, flags); 702 } 703 704 /* ------------------------------------------------------------------------ 705 * Stream statistics 706 */ 707 708 static void uvc_video_stats_decode(struct uvc_streaming *stream, 709 const __u8 *data, int len) 710 { 711 unsigned int header_size; 712 bool has_pts = false; 713 bool has_scr = false; 714 u16 uninitialized_var(scr_sof); 715 u32 uninitialized_var(scr_stc); 716 u32 uninitialized_var(pts); 717 718 if (stream->stats.stream.nb_frames == 0 && 719 stream->stats.frame.nb_packets == 0) 720 ktime_get_ts(&stream->stats.stream.start_ts); 721 722 switch (data[1] & (UVC_STREAM_PTS | UVC_STREAM_SCR)) { 723 case UVC_STREAM_PTS | UVC_STREAM_SCR: 724 header_size = 12; 725 has_pts = true; 726 has_scr = true; 727 break; 728 case UVC_STREAM_PTS: 729 header_size = 6; 730 has_pts = true; 731 break; 732 case UVC_STREAM_SCR: 733 header_size = 8; 734 has_scr = true; 735 break; 736 default: 737 header_size = 2; 738 break; 739 } 740 741 /* Check for invalid headers. */ 742 if (len < header_size || data[0] < header_size) { 743 stream->stats.frame.nb_invalid++; 744 return; 745 } 746 747 /* Extract the timestamps. */ 748 if (has_pts) 749 pts = get_unaligned_le32(&data[2]); 750 751 if (has_scr) { 752 scr_stc = get_unaligned_le32(&data[header_size - 6]); 753 scr_sof = get_unaligned_le16(&data[header_size - 2]); 754 } 755 756 /* Is PTS constant through the whole frame ? */ 757 if (has_pts && stream->stats.frame.nb_pts) { 758 if (stream->stats.frame.pts != pts) { 759 stream->stats.frame.nb_pts_diffs++; 760 stream->stats.frame.last_pts_diff = 761 stream->stats.frame.nb_packets; 762 } 763 } 764 765 if (has_pts) { 766 stream->stats.frame.nb_pts++; 767 stream->stats.frame.pts = pts; 768 } 769 770 /* Do all frames have a PTS in their first non-empty packet, or before 771 * their first empty packet ? 772 */ 773 if (stream->stats.frame.size == 0) { 774 if (len > header_size) 775 stream->stats.frame.has_initial_pts = has_pts; 776 if (len == header_size && has_pts) 777 stream->stats.frame.has_early_pts = true; 778 } 779 780 /* Do the SCR.STC and SCR.SOF fields vary through the frame ? */ 781 if (has_scr && stream->stats.frame.nb_scr) { 782 if (stream->stats.frame.scr_stc != scr_stc) 783 stream->stats.frame.nb_scr_diffs++; 784 } 785 786 if (has_scr) { 787 /* Expand the SOF counter to 32 bits and store its value. */ 788 if (stream->stats.stream.nb_frames > 0 || 789 stream->stats.frame.nb_scr > 0) 790 stream->stats.stream.scr_sof_count += 791 (scr_sof - stream->stats.stream.scr_sof) % 2048; 792 stream->stats.stream.scr_sof = scr_sof; 793 794 stream->stats.frame.nb_scr++; 795 stream->stats.frame.scr_stc = scr_stc; 796 stream->stats.frame.scr_sof = scr_sof; 797 798 if (scr_sof < stream->stats.stream.min_sof) 799 stream->stats.stream.min_sof = scr_sof; 800 if (scr_sof > stream->stats.stream.max_sof) 801 stream->stats.stream.max_sof = scr_sof; 802 } 803 804 /* Record the first non-empty packet number. */ 805 if (stream->stats.frame.size == 0 && len > header_size) 806 stream->stats.frame.first_data = stream->stats.frame.nb_packets; 807 808 /* Update the frame size. */ 809 stream->stats.frame.size += len - header_size; 810 811 /* Update the packets counters. */ 812 stream->stats.frame.nb_packets++; 813 if (len > header_size) 814 stream->stats.frame.nb_empty++; 815 816 if (data[1] & UVC_STREAM_ERR) 817 stream->stats.frame.nb_errors++; 818 } 819 820 static void uvc_video_stats_update(struct uvc_streaming *stream) 821 { 822 struct uvc_stats_frame *frame = &stream->stats.frame; 823 824 uvc_trace(UVC_TRACE_STATS, "frame %u stats: %u/%u/%u packets, " 825 "%u/%u/%u pts (%searly %sinitial), %u/%u scr, " 826 "last pts/stc/sof %u/%u/%u\n", 827 stream->sequence, frame->first_data, 828 frame->nb_packets - frame->nb_empty, frame->nb_packets, 829 frame->nb_pts_diffs, frame->last_pts_diff, frame->nb_pts, 830 frame->has_early_pts ? "" : "!", 831 frame->has_initial_pts ? "" : "!", 832 frame->nb_scr_diffs, frame->nb_scr, 833 frame->pts, frame->scr_stc, frame->scr_sof); 834 835 stream->stats.stream.nb_frames++; 836 stream->stats.stream.nb_packets += stream->stats.frame.nb_packets; 837 stream->stats.stream.nb_empty += stream->stats.frame.nb_empty; 838 stream->stats.stream.nb_errors += stream->stats.frame.nb_errors; 839 stream->stats.stream.nb_invalid += stream->stats.frame.nb_invalid; 840 841 if (frame->has_early_pts) 842 stream->stats.stream.nb_pts_early++; 843 if (frame->has_initial_pts) 844 stream->stats.stream.nb_pts_initial++; 845 if (frame->last_pts_diff <= frame->first_data) 846 stream->stats.stream.nb_pts_constant++; 847 if (frame->nb_scr >= frame->nb_packets - frame->nb_empty) 848 stream->stats.stream.nb_scr_count_ok++; 849 if (frame->nb_scr_diffs + 1 == frame->nb_scr) 850 stream->stats.stream.nb_scr_diffs_ok++; 851 852 memset(&stream->stats.frame, 0, sizeof(stream->stats.frame)); 853 } 854 855 size_t uvc_video_stats_dump(struct uvc_streaming *stream, char *buf, 856 size_t size) 857 { 858 unsigned int scr_sof_freq; 859 unsigned int duration; 860 struct timespec ts; 861 size_t count = 0; 862 863 ts.tv_sec = stream->stats.stream.stop_ts.tv_sec 864 - stream->stats.stream.start_ts.tv_sec; 865 ts.tv_nsec = stream->stats.stream.stop_ts.tv_nsec 866 - stream->stats.stream.start_ts.tv_nsec; 867 if (ts.tv_nsec < 0) { 868 ts.tv_sec--; 869 ts.tv_nsec += 1000000000; 870 } 871 872 /* Compute the SCR.SOF frequency estimate. At the nominal 1kHz SOF 873 * frequency this will not overflow before more than 1h. 874 */ 875 duration = ts.tv_sec * 1000 + ts.tv_nsec / 1000000; 876 if (duration != 0) 877 scr_sof_freq = stream->stats.stream.scr_sof_count * 1000 878 / duration; 879 else 880 scr_sof_freq = 0; 881 882 count += scnprintf(buf + count, size - count, 883 "frames: %u\npackets: %u\nempty: %u\n" 884 "errors: %u\ninvalid: %u\n", 885 stream->stats.stream.nb_frames, 886 stream->stats.stream.nb_packets, 887 stream->stats.stream.nb_empty, 888 stream->stats.stream.nb_errors, 889 stream->stats.stream.nb_invalid); 890 count += scnprintf(buf + count, size - count, 891 "pts: %u early, %u initial, %u ok\n", 892 stream->stats.stream.nb_pts_early, 893 stream->stats.stream.nb_pts_initial, 894 stream->stats.stream.nb_pts_constant); 895 count += scnprintf(buf + count, size - count, 896 "scr: %u count ok, %u diff ok\n", 897 stream->stats.stream.nb_scr_count_ok, 898 stream->stats.stream.nb_scr_diffs_ok); 899 count += scnprintf(buf + count, size - count, 900 "sof: %u <= sof <= %u, freq %u.%03u kHz\n", 901 stream->stats.stream.min_sof, 902 stream->stats.stream.max_sof, 903 scr_sof_freq / 1000, scr_sof_freq % 1000); 904 905 return count; 906 } 907 908 static void uvc_video_stats_start(struct uvc_streaming *stream) 909 { 910 memset(&stream->stats, 0, sizeof(stream->stats)); 911 stream->stats.stream.min_sof = 2048; 912 } 913 914 static void uvc_video_stats_stop(struct uvc_streaming *stream) 915 { 916 ktime_get_ts(&stream->stats.stream.stop_ts); 917 } 918 919 /* ------------------------------------------------------------------------ 920 * Video codecs 921 */ 922 923 /* Video payload decoding is handled by uvc_video_decode_start(), 924 * uvc_video_decode_data() and uvc_video_decode_end(). 925 * 926 * uvc_video_decode_start is called with URB data at the start of a bulk or 927 * isochronous payload. It processes header data and returns the header size 928 * in bytes if successful. If an error occurs, it returns a negative error 929 * code. The following error codes have special meanings. 930 * 931 * - EAGAIN informs the caller that the current video buffer should be marked 932 * as done, and that the function should be called again with the same data 933 * and a new video buffer. This is used when end of frame conditions can be 934 * reliably detected at the beginning of the next frame only. 935 * 936 * If an error other than -EAGAIN is returned, the caller will drop the current 937 * payload. No call to uvc_video_decode_data and uvc_video_decode_end will be 938 * made until the next payload. -ENODATA can be used to drop the current 939 * payload if no other error code is appropriate. 940 * 941 * uvc_video_decode_data is called for every URB with URB data. It copies the 942 * data to the video buffer. 943 * 944 * uvc_video_decode_end is called with header data at the end of a bulk or 945 * isochronous payload. It performs any additional header data processing and 946 * returns 0 or a negative error code if an error occurred. As header data have 947 * already been processed by uvc_video_decode_start, this functions isn't 948 * required to perform sanity checks a second time. 949 * 950 * For isochronous transfers where a payload is always transferred in a single 951 * URB, the three functions will be called in a row. 952 * 953 * To let the decoder process header data and update its internal state even 954 * when no video buffer is available, uvc_video_decode_start must be prepared 955 * to be called with a NULL buf parameter. uvc_video_decode_data and 956 * uvc_video_decode_end will never be called with a NULL buffer. 957 */ 958 static int uvc_video_decode_start(struct uvc_streaming *stream, 959 struct uvc_buffer *buf, const __u8 *data, int len) 960 { 961 __u8 fid; 962 963 /* Sanity checks: 964 * - packet must be at least 2 bytes long 965 * - bHeaderLength value must be at least 2 bytes (see above) 966 * - bHeaderLength value can't be larger than the packet size. 967 */ 968 if (len < 2 || data[0] < 2 || data[0] > len) { 969 stream->stats.frame.nb_invalid++; 970 return -EINVAL; 971 } 972 973 fid = data[1] & UVC_STREAM_FID; 974 975 /* Increase the sequence number regardless of any buffer states, so 976 * that discontinuous sequence numbers always indicate lost frames. 977 */ 978 if (stream->last_fid != fid) { 979 stream->sequence++; 980 if (stream->sequence) 981 uvc_video_stats_update(stream); 982 } 983 984 uvc_video_clock_decode(stream, buf, data, len); 985 uvc_video_stats_decode(stream, data, len); 986 987 /* Store the payload FID bit and return immediately when the buffer is 988 * NULL. 989 */ 990 if (buf == NULL) { 991 stream->last_fid = fid; 992 return -ENODATA; 993 } 994 995 /* Mark the buffer as bad if the error bit is set. */ 996 if (data[1] & UVC_STREAM_ERR) { 997 uvc_trace(UVC_TRACE_FRAME, "Marking buffer as bad (error bit " 998 "set).\n"); 999 buf->error = 1; 1000 } 1001 1002 /* Synchronize to the input stream by waiting for the FID bit to be 1003 * toggled when the the buffer state is not UVC_BUF_STATE_ACTIVE. 1004 * stream->last_fid is initialized to -1, so the first isochronous 1005 * frame will always be in sync. 1006 * 1007 * If the device doesn't toggle the FID bit, invert stream->last_fid 1008 * when the EOF bit is set to force synchronisation on the next packet. 1009 */ 1010 if (buf->state != UVC_BUF_STATE_ACTIVE) { 1011 struct timespec ts; 1012 1013 if (fid == stream->last_fid) { 1014 uvc_trace(UVC_TRACE_FRAME, "Dropping payload (out of " 1015 "sync).\n"); 1016 if ((stream->dev->quirks & UVC_QUIRK_STREAM_NO_FID) && 1017 (data[1] & UVC_STREAM_EOF)) 1018 stream->last_fid ^= UVC_STREAM_FID; 1019 return -ENODATA; 1020 } 1021 1022 uvc_video_get_ts(&ts); 1023 1024 buf->buf.v4l2_buf.sequence = stream->sequence; 1025 buf->buf.v4l2_buf.timestamp.tv_sec = ts.tv_sec; 1026 buf->buf.v4l2_buf.timestamp.tv_usec = 1027 ts.tv_nsec / NSEC_PER_USEC; 1028 1029 /* TODO: Handle PTS and SCR. */ 1030 buf->state = UVC_BUF_STATE_ACTIVE; 1031 } 1032 1033 /* Mark the buffer as done if we're at the beginning of a new frame. 1034 * End of frame detection is better implemented by checking the EOF 1035 * bit (FID bit toggling is delayed by one frame compared to the EOF 1036 * bit), but some devices don't set the bit at end of frame (and the 1037 * last payload can be lost anyway). We thus must check if the FID has 1038 * been toggled. 1039 * 1040 * stream->last_fid is initialized to -1, so the first isochronous 1041 * frame will never trigger an end of frame detection. 1042 * 1043 * Empty buffers (bytesused == 0) don't trigger end of frame detection 1044 * as it doesn't make sense to return an empty buffer. This also 1045 * avoids detecting end of frame conditions at FID toggling if the 1046 * previous payload had the EOF bit set. 1047 */ 1048 if (fid != stream->last_fid && buf->bytesused != 0) { 1049 uvc_trace(UVC_TRACE_FRAME, "Frame complete (FID bit " 1050 "toggled).\n"); 1051 buf->state = UVC_BUF_STATE_READY; 1052 return -EAGAIN; 1053 } 1054 1055 stream->last_fid = fid; 1056 1057 return data[0]; 1058 } 1059 1060 static void uvc_video_decode_data(struct uvc_streaming *stream, 1061 struct uvc_buffer *buf, const __u8 *data, int len) 1062 { 1063 unsigned int maxlen, nbytes; 1064 void *mem; 1065 1066 if (len <= 0) 1067 return; 1068 1069 /* Copy the video data to the buffer. */ 1070 maxlen = buf->length - buf->bytesused; 1071 mem = buf->mem + buf->bytesused; 1072 nbytes = min((unsigned int)len, maxlen); 1073 memcpy(mem, data, nbytes); 1074 buf->bytesused += nbytes; 1075 1076 /* Complete the current frame if the buffer size was exceeded. */ 1077 if (len > maxlen) { 1078 uvc_trace(UVC_TRACE_FRAME, "Frame complete (overflow).\n"); 1079 buf->state = UVC_BUF_STATE_READY; 1080 } 1081 } 1082 1083 static void uvc_video_decode_end(struct uvc_streaming *stream, 1084 struct uvc_buffer *buf, const __u8 *data, int len) 1085 { 1086 /* Mark the buffer as done if the EOF marker is set. */ 1087 if (data[1] & UVC_STREAM_EOF && buf->bytesused != 0) { 1088 uvc_trace(UVC_TRACE_FRAME, "Frame complete (EOF found).\n"); 1089 if (data[0] == len) 1090 uvc_trace(UVC_TRACE_FRAME, "EOF in empty payload.\n"); 1091 buf->state = UVC_BUF_STATE_READY; 1092 if (stream->dev->quirks & UVC_QUIRK_STREAM_NO_FID) 1093 stream->last_fid ^= UVC_STREAM_FID; 1094 } 1095 } 1096 1097 /* Video payload encoding is handled by uvc_video_encode_header() and 1098 * uvc_video_encode_data(). Only bulk transfers are currently supported. 1099 * 1100 * uvc_video_encode_header is called at the start of a payload. It adds header 1101 * data to the transfer buffer and returns the header size. As the only known 1102 * UVC output device transfers a whole frame in a single payload, the EOF bit 1103 * is always set in the header. 1104 * 1105 * uvc_video_encode_data is called for every URB and copies the data from the 1106 * video buffer to the transfer buffer. 1107 */ 1108 static int uvc_video_encode_header(struct uvc_streaming *stream, 1109 struct uvc_buffer *buf, __u8 *data, int len) 1110 { 1111 data[0] = 2; /* Header length */ 1112 data[1] = UVC_STREAM_EOH | UVC_STREAM_EOF 1113 | (stream->last_fid & UVC_STREAM_FID); 1114 return 2; 1115 } 1116 1117 static int uvc_video_encode_data(struct uvc_streaming *stream, 1118 struct uvc_buffer *buf, __u8 *data, int len) 1119 { 1120 struct uvc_video_queue *queue = &stream->queue; 1121 unsigned int nbytes; 1122 void *mem; 1123 1124 /* Copy video data to the URB buffer. */ 1125 mem = buf->mem + queue->buf_used; 1126 nbytes = min((unsigned int)len, buf->bytesused - queue->buf_used); 1127 nbytes = min(stream->bulk.max_payload_size - stream->bulk.payload_size, 1128 nbytes); 1129 memcpy(data, mem, nbytes); 1130 1131 queue->buf_used += nbytes; 1132 1133 return nbytes; 1134 } 1135 1136 /* ------------------------------------------------------------------------ 1137 * URB handling 1138 */ 1139 1140 /* 1141 * Set error flag for incomplete buffer. 1142 */ 1143 static void uvc_video_validate_buffer(const struct uvc_streaming *stream, 1144 struct uvc_buffer *buf) 1145 { 1146 if (buf->length != buf->bytesused && 1147 !(stream->cur_format->flags & UVC_FMT_FLAG_COMPRESSED)) 1148 buf->error = 1; 1149 } 1150 1151 /* 1152 * Completion handler for video URBs. 1153 */ 1154 static void uvc_video_decode_isoc(struct urb *urb, struct uvc_streaming *stream, 1155 struct uvc_buffer *buf) 1156 { 1157 u8 *mem; 1158 int ret, i; 1159 1160 for (i = 0; i < urb->number_of_packets; ++i) { 1161 if (urb->iso_frame_desc[i].status < 0) { 1162 uvc_trace(UVC_TRACE_FRAME, "USB isochronous frame " 1163 "lost (%d).\n", urb->iso_frame_desc[i].status); 1164 /* Mark the buffer as faulty. */ 1165 if (buf != NULL) 1166 buf->error = 1; 1167 continue; 1168 } 1169 1170 /* Decode the payload header. */ 1171 mem = urb->transfer_buffer + urb->iso_frame_desc[i].offset; 1172 do { 1173 ret = uvc_video_decode_start(stream, buf, mem, 1174 urb->iso_frame_desc[i].actual_length); 1175 if (ret == -EAGAIN) { 1176 uvc_video_validate_buffer(stream, buf); 1177 buf = uvc_queue_next_buffer(&stream->queue, 1178 buf); 1179 } 1180 } while (ret == -EAGAIN); 1181 1182 if (ret < 0) 1183 continue; 1184 1185 /* Decode the payload data. */ 1186 uvc_video_decode_data(stream, buf, mem + ret, 1187 urb->iso_frame_desc[i].actual_length - ret); 1188 1189 /* Process the header again. */ 1190 uvc_video_decode_end(stream, buf, mem, 1191 urb->iso_frame_desc[i].actual_length); 1192 1193 if (buf->state == UVC_BUF_STATE_READY) { 1194 uvc_video_validate_buffer(stream, buf); 1195 buf = uvc_queue_next_buffer(&stream->queue, buf); 1196 } 1197 } 1198 } 1199 1200 static void uvc_video_decode_bulk(struct urb *urb, struct uvc_streaming *stream, 1201 struct uvc_buffer *buf) 1202 { 1203 u8 *mem; 1204 int len, ret; 1205 1206 /* 1207 * Ignore ZLPs if they're not part of a frame, otherwise process them 1208 * to trigger the end of payload detection. 1209 */ 1210 if (urb->actual_length == 0 && stream->bulk.header_size == 0) 1211 return; 1212 1213 mem = urb->transfer_buffer; 1214 len = urb->actual_length; 1215 stream->bulk.payload_size += len; 1216 1217 /* If the URB is the first of its payload, decode and save the 1218 * header. 1219 */ 1220 if (stream->bulk.header_size == 0 && !stream->bulk.skip_payload) { 1221 do { 1222 ret = uvc_video_decode_start(stream, buf, mem, len); 1223 if (ret == -EAGAIN) 1224 buf = uvc_queue_next_buffer(&stream->queue, 1225 buf); 1226 } while (ret == -EAGAIN); 1227 1228 /* If an error occurred skip the rest of the payload. */ 1229 if (ret < 0 || buf == NULL) { 1230 stream->bulk.skip_payload = 1; 1231 } else { 1232 memcpy(stream->bulk.header, mem, ret); 1233 stream->bulk.header_size = ret; 1234 1235 mem += ret; 1236 len -= ret; 1237 } 1238 } 1239 1240 /* The buffer queue might have been cancelled while a bulk transfer 1241 * was in progress, so we can reach here with buf equal to NULL. Make 1242 * sure buf is never dereferenced if NULL. 1243 */ 1244 1245 /* Process video data. */ 1246 if (!stream->bulk.skip_payload && buf != NULL) 1247 uvc_video_decode_data(stream, buf, mem, len); 1248 1249 /* Detect the payload end by a URB smaller than the maximum size (or 1250 * a payload size equal to the maximum) and process the header again. 1251 */ 1252 if (urb->actual_length < urb->transfer_buffer_length || 1253 stream->bulk.payload_size >= stream->bulk.max_payload_size) { 1254 if (!stream->bulk.skip_payload && buf != NULL) { 1255 uvc_video_decode_end(stream, buf, stream->bulk.header, 1256 stream->bulk.payload_size); 1257 if (buf->state == UVC_BUF_STATE_READY) 1258 buf = uvc_queue_next_buffer(&stream->queue, 1259 buf); 1260 } 1261 1262 stream->bulk.header_size = 0; 1263 stream->bulk.skip_payload = 0; 1264 stream->bulk.payload_size = 0; 1265 } 1266 } 1267 1268 static void uvc_video_encode_bulk(struct urb *urb, struct uvc_streaming *stream, 1269 struct uvc_buffer *buf) 1270 { 1271 u8 *mem = urb->transfer_buffer; 1272 int len = stream->urb_size, ret; 1273 1274 if (buf == NULL) { 1275 urb->transfer_buffer_length = 0; 1276 return; 1277 } 1278 1279 /* If the URB is the first of its payload, add the header. */ 1280 if (stream->bulk.header_size == 0) { 1281 ret = uvc_video_encode_header(stream, buf, mem, len); 1282 stream->bulk.header_size = ret; 1283 stream->bulk.payload_size += ret; 1284 mem += ret; 1285 len -= ret; 1286 } 1287 1288 /* Process video data. */ 1289 ret = uvc_video_encode_data(stream, buf, mem, len); 1290 1291 stream->bulk.payload_size += ret; 1292 len -= ret; 1293 1294 if (buf->bytesused == stream->queue.buf_used || 1295 stream->bulk.payload_size == stream->bulk.max_payload_size) { 1296 if (buf->bytesused == stream->queue.buf_used) { 1297 stream->queue.buf_used = 0; 1298 buf->state = UVC_BUF_STATE_READY; 1299 buf->buf.v4l2_buf.sequence = ++stream->sequence; 1300 uvc_queue_next_buffer(&stream->queue, buf); 1301 stream->last_fid ^= UVC_STREAM_FID; 1302 } 1303 1304 stream->bulk.header_size = 0; 1305 stream->bulk.payload_size = 0; 1306 } 1307 1308 urb->transfer_buffer_length = stream->urb_size - len; 1309 } 1310 1311 static void uvc_video_complete(struct urb *urb) 1312 { 1313 struct uvc_streaming *stream = urb->context; 1314 struct uvc_video_queue *queue = &stream->queue; 1315 struct uvc_buffer *buf = NULL; 1316 unsigned long flags; 1317 int ret; 1318 1319 switch (urb->status) { 1320 case 0: 1321 break; 1322 1323 default: 1324 uvc_printk(KERN_WARNING, "Non-zero status (%d) in video " 1325 "completion handler.\n", urb->status); 1326 1327 case -ENOENT: /* usb_kill_urb() called. */ 1328 if (stream->frozen) 1329 return; 1330 1331 case -ECONNRESET: /* usb_unlink_urb() called. */ 1332 case -ESHUTDOWN: /* The endpoint is being disabled. */ 1333 uvc_queue_cancel(queue, urb->status == -ESHUTDOWN); 1334 return; 1335 } 1336 1337 spin_lock_irqsave(&queue->irqlock, flags); 1338 if (!list_empty(&queue->irqqueue)) 1339 buf = list_first_entry(&queue->irqqueue, struct uvc_buffer, 1340 queue); 1341 spin_unlock_irqrestore(&queue->irqlock, flags); 1342 1343 stream->decode(urb, stream, buf); 1344 1345 if ((ret = usb_submit_urb(urb, GFP_ATOMIC)) < 0) { 1346 uvc_printk(KERN_ERR, "Failed to resubmit video URB (%d).\n", 1347 ret); 1348 } 1349 } 1350 1351 /* 1352 * Free transfer buffers. 1353 */ 1354 static void uvc_free_urb_buffers(struct uvc_streaming *stream) 1355 { 1356 unsigned int i; 1357 1358 for (i = 0; i < UVC_URBS; ++i) { 1359 if (stream->urb_buffer[i]) { 1360 #ifndef CONFIG_DMA_NONCOHERENT 1361 usb_free_coherent(stream->dev->udev, stream->urb_size, 1362 stream->urb_buffer[i], stream->urb_dma[i]); 1363 #else 1364 kfree(stream->urb_buffer[i]); 1365 #endif 1366 stream->urb_buffer[i] = NULL; 1367 } 1368 } 1369 1370 stream->urb_size = 0; 1371 } 1372 1373 /* 1374 * Allocate transfer buffers. This function can be called with buffers 1375 * already allocated when resuming from suspend, in which case it will 1376 * return without touching the buffers. 1377 * 1378 * Limit the buffer size to UVC_MAX_PACKETS bulk/isochronous packets. If the 1379 * system is too low on memory try successively smaller numbers of packets 1380 * until allocation succeeds. 1381 * 1382 * Return the number of allocated packets on success or 0 when out of memory. 1383 */ 1384 static int uvc_alloc_urb_buffers(struct uvc_streaming *stream, 1385 unsigned int size, unsigned int psize, gfp_t gfp_flags) 1386 { 1387 unsigned int npackets; 1388 unsigned int i; 1389 1390 /* Buffers are already allocated, bail out. */ 1391 if (stream->urb_size) 1392 return stream->urb_size / psize; 1393 1394 /* Compute the number of packets. Bulk endpoints might transfer UVC 1395 * payloads across multiple URBs. 1396 */ 1397 npackets = DIV_ROUND_UP(size, psize); 1398 if (npackets > UVC_MAX_PACKETS) 1399 npackets = UVC_MAX_PACKETS; 1400 1401 /* Retry allocations until one succeed. */ 1402 for (; npackets > 1; npackets /= 2) { 1403 for (i = 0; i < UVC_URBS; ++i) { 1404 stream->urb_size = psize * npackets; 1405 #ifndef CONFIG_DMA_NONCOHERENT 1406 stream->urb_buffer[i] = usb_alloc_coherent( 1407 stream->dev->udev, stream->urb_size, 1408 gfp_flags | __GFP_NOWARN, &stream->urb_dma[i]); 1409 #else 1410 stream->urb_buffer[i] = 1411 kmalloc(stream->urb_size, gfp_flags | __GFP_NOWARN); 1412 #endif 1413 if (!stream->urb_buffer[i]) { 1414 uvc_free_urb_buffers(stream); 1415 break; 1416 } 1417 } 1418 1419 if (i == UVC_URBS) { 1420 uvc_trace(UVC_TRACE_VIDEO, "Allocated %u URB buffers " 1421 "of %ux%u bytes each.\n", UVC_URBS, npackets, 1422 psize); 1423 return npackets; 1424 } 1425 } 1426 1427 uvc_trace(UVC_TRACE_VIDEO, "Failed to allocate URB buffers (%u bytes " 1428 "per packet).\n", psize); 1429 return 0; 1430 } 1431 1432 /* 1433 * Uninitialize isochronous/bulk URBs and free transfer buffers. 1434 */ 1435 static void uvc_uninit_video(struct uvc_streaming *stream, int free_buffers) 1436 { 1437 struct urb *urb; 1438 unsigned int i; 1439 1440 uvc_video_stats_stop(stream); 1441 1442 for (i = 0; i < UVC_URBS; ++i) { 1443 urb = stream->urb[i]; 1444 if (urb == NULL) 1445 continue; 1446 1447 usb_kill_urb(urb); 1448 usb_free_urb(urb); 1449 stream->urb[i] = NULL; 1450 } 1451 1452 if (free_buffers) 1453 uvc_free_urb_buffers(stream); 1454 } 1455 1456 /* 1457 * Compute the maximum number of bytes per interval for an endpoint. 1458 */ 1459 static unsigned int uvc_endpoint_max_bpi(struct usb_device *dev, 1460 struct usb_host_endpoint *ep) 1461 { 1462 u16 psize; 1463 1464 switch (dev->speed) { 1465 case USB_SPEED_SUPER: 1466 return ep->ss_ep_comp.wBytesPerInterval; 1467 case USB_SPEED_HIGH: 1468 psize = usb_endpoint_maxp(&ep->desc); 1469 return (psize & 0x07ff) * (1 + ((psize >> 11) & 3)); 1470 case USB_SPEED_WIRELESS: 1471 psize = usb_endpoint_maxp(&ep->desc); 1472 return psize; 1473 default: 1474 psize = usb_endpoint_maxp(&ep->desc); 1475 return psize & 0x07ff; 1476 } 1477 } 1478 1479 /* 1480 * Initialize isochronous URBs and allocate transfer buffers. The packet size 1481 * is given by the endpoint. 1482 */ 1483 static int uvc_init_video_isoc(struct uvc_streaming *stream, 1484 struct usb_host_endpoint *ep, gfp_t gfp_flags) 1485 { 1486 struct urb *urb; 1487 unsigned int npackets, i, j; 1488 u16 psize; 1489 u32 size; 1490 1491 psize = uvc_endpoint_max_bpi(stream->dev->udev, ep); 1492 size = stream->ctrl.dwMaxVideoFrameSize; 1493 1494 npackets = uvc_alloc_urb_buffers(stream, size, psize, gfp_flags); 1495 if (npackets == 0) 1496 return -ENOMEM; 1497 1498 size = npackets * psize; 1499 1500 for (i = 0; i < UVC_URBS; ++i) { 1501 urb = usb_alloc_urb(npackets, gfp_flags); 1502 if (urb == NULL) { 1503 uvc_uninit_video(stream, 1); 1504 return -ENOMEM; 1505 } 1506 1507 urb->dev = stream->dev->udev; 1508 urb->context = stream; 1509 urb->pipe = usb_rcvisocpipe(stream->dev->udev, 1510 ep->desc.bEndpointAddress); 1511 #ifndef CONFIG_DMA_NONCOHERENT 1512 urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP; 1513 urb->transfer_dma = stream->urb_dma[i]; 1514 #else 1515 urb->transfer_flags = URB_ISO_ASAP; 1516 #endif 1517 urb->interval = ep->desc.bInterval; 1518 urb->transfer_buffer = stream->urb_buffer[i]; 1519 urb->complete = uvc_video_complete; 1520 urb->number_of_packets = npackets; 1521 urb->transfer_buffer_length = size; 1522 1523 for (j = 0; j < npackets; ++j) { 1524 urb->iso_frame_desc[j].offset = j * psize; 1525 urb->iso_frame_desc[j].length = psize; 1526 } 1527 1528 stream->urb[i] = urb; 1529 } 1530 1531 return 0; 1532 } 1533 1534 /* 1535 * Initialize bulk URBs and allocate transfer buffers. The packet size is 1536 * given by the endpoint. 1537 */ 1538 static int uvc_init_video_bulk(struct uvc_streaming *stream, 1539 struct usb_host_endpoint *ep, gfp_t gfp_flags) 1540 { 1541 struct urb *urb; 1542 unsigned int npackets, pipe, i; 1543 u16 psize; 1544 u32 size; 1545 1546 psize = usb_endpoint_maxp(&ep->desc) & 0x7ff; 1547 size = stream->ctrl.dwMaxPayloadTransferSize; 1548 stream->bulk.max_payload_size = size; 1549 1550 npackets = uvc_alloc_urb_buffers(stream, size, psize, gfp_flags); 1551 if (npackets == 0) 1552 return -ENOMEM; 1553 1554 size = npackets * psize; 1555 1556 if (usb_endpoint_dir_in(&ep->desc)) 1557 pipe = usb_rcvbulkpipe(stream->dev->udev, 1558 ep->desc.bEndpointAddress); 1559 else 1560 pipe = usb_sndbulkpipe(stream->dev->udev, 1561 ep->desc.bEndpointAddress); 1562 1563 if (stream->type == V4L2_BUF_TYPE_VIDEO_OUTPUT) 1564 size = 0; 1565 1566 for (i = 0; i < UVC_URBS; ++i) { 1567 urb = usb_alloc_urb(0, gfp_flags); 1568 if (urb == NULL) { 1569 uvc_uninit_video(stream, 1); 1570 return -ENOMEM; 1571 } 1572 1573 usb_fill_bulk_urb(urb, stream->dev->udev, pipe, 1574 stream->urb_buffer[i], size, uvc_video_complete, 1575 stream); 1576 #ifndef CONFIG_DMA_NONCOHERENT 1577 urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP; 1578 urb->transfer_dma = stream->urb_dma[i]; 1579 #endif 1580 1581 stream->urb[i] = urb; 1582 } 1583 1584 return 0; 1585 } 1586 1587 /* 1588 * Initialize isochronous/bulk URBs and allocate transfer buffers. 1589 */ 1590 static int uvc_init_video(struct uvc_streaming *stream, gfp_t gfp_flags) 1591 { 1592 struct usb_interface *intf = stream->intf; 1593 struct usb_host_endpoint *ep; 1594 unsigned int i; 1595 int ret; 1596 1597 stream->sequence = -1; 1598 stream->last_fid = -1; 1599 stream->bulk.header_size = 0; 1600 stream->bulk.skip_payload = 0; 1601 stream->bulk.payload_size = 0; 1602 1603 uvc_video_stats_start(stream); 1604 1605 if (intf->num_altsetting > 1) { 1606 struct usb_host_endpoint *best_ep = NULL; 1607 unsigned int best_psize = UINT_MAX; 1608 unsigned int bandwidth; 1609 unsigned int uninitialized_var(altsetting); 1610 int intfnum = stream->intfnum; 1611 1612 /* Isochronous endpoint, select the alternate setting. */ 1613 bandwidth = stream->ctrl.dwMaxPayloadTransferSize; 1614 1615 if (bandwidth == 0) { 1616 uvc_trace(UVC_TRACE_VIDEO, "Device requested null " 1617 "bandwidth, defaulting to lowest.\n"); 1618 bandwidth = 1; 1619 } else { 1620 uvc_trace(UVC_TRACE_VIDEO, "Device requested %u " 1621 "B/frame bandwidth.\n", bandwidth); 1622 } 1623 1624 for (i = 0; i < intf->num_altsetting; ++i) { 1625 struct usb_host_interface *alts; 1626 unsigned int psize; 1627 1628 alts = &intf->altsetting[i]; 1629 ep = uvc_find_endpoint(alts, 1630 stream->header.bEndpointAddress); 1631 if (ep == NULL) 1632 continue; 1633 1634 /* Check if the bandwidth is high enough. */ 1635 psize = uvc_endpoint_max_bpi(stream->dev->udev, ep); 1636 if (psize >= bandwidth && psize <= best_psize) { 1637 altsetting = alts->desc.bAlternateSetting; 1638 best_psize = psize; 1639 best_ep = ep; 1640 } 1641 } 1642 1643 if (best_ep == NULL) { 1644 uvc_trace(UVC_TRACE_VIDEO, "No fast enough alt setting " 1645 "for requested bandwidth.\n"); 1646 return -EIO; 1647 } 1648 1649 uvc_trace(UVC_TRACE_VIDEO, "Selecting alternate setting %u " 1650 "(%u B/frame bandwidth).\n", altsetting, best_psize); 1651 1652 ret = usb_set_interface(stream->dev->udev, intfnum, altsetting); 1653 if (ret < 0) 1654 return ret; 1655 1656 ret = uvc_init_video_isoc(stream, best_ep, gfp_flags); 1657 } else { 1658 /* Bulk endpoint, proceed to URB initialization. */ 1659 ep = uvc_find_endpoint(&intf->altsetting[0], 1660 stream->header.bEndpointAddress); 1661 if (ep == NULL) 1662 return -EIO; 1663 1664 ret = uvc_init_video_bulk(stream, ep, gfp_flags); 1665 } 1666 1667 if (ret < 0) 1668 return ret; 1669 1670 /* Submit the URBs. */ 1671 for (i = 0; i < UVC_URBS; ++i) { 1672 ret = usb_submit_urb(stream->urb[i], gfp_flags); 1673 if (ret < 0) { 1674 uvc_printk(KERN_ERR, "Failed to submit URB %u " 1675 "(%d).\n", i, ret); 1676 uvc_uninit_video(stream, 1); 1677 return ret; 1678 } 1679 } 1680 1681 return 0; 1682 } 1683 1684 /* -------------------------------------------------------------------------- 1685 * Suspend/resume 1686 */ 1687 1688 /* 1689 * Stop streaming without disabling the video queue. 1690 * 1691 * To let userspace applications resume without trouble, we must not touch the 1692 * video buffers in any way. We mark the device as frozen to make sure the URB 1693 * completion handler won't try to cancel the queue when we kill the URBs. 1694 */ 1695 int uvc_video_suspend(struct uvc_streaming *stream) 1696 { 1697 if (!uvc_queue_streaming(&stream->queue)) 1698 return 0; 1699 1700 stream->frozen = 1; 1701 uvc_uninit_video(stream, 0); 1702 usb_set_interface(stream->dev->udev, stream->intfnum, 0); 1703 return 0; 1704 } 1705 1706 /* 1707 * Reconfigure the video interface and restart streaming if it was enabled 1708 * before suspend. 1709 * 1710 * If an error occurs, disable the video queue. This will wake all pending 1711 * buffers, making sure userspace applications are notified of the problem 1712 * instead of waiting forever. 1713 */ 1714 int uvc_video_resume(struct uvc_streaming *stream, int reset) 1715 { 1716 int ret; 1717 1718 /* If the bus has been reset on resume, set the alternate setting to 0. 1719 * This should be the default value, but some devices crash or otherwise 1720 * misbehave if they don't receive a SET_INTERFACE request before any 1721 * other video control request. 1722 */ 1723 if (reset) 1724 usb_set_interface(stream->dev->udev, stream->intfnum, 0); 1725 1726 stream->frozen = 0; 1727 1728 uvc_video_clock_reset(stream); 1729 1730 ret = uvc_commit_video(stream, &stream->ctrl); 1731 if (ret < 0) { 1732 uvc_queue_enable(&stream->queue, 0); 1733 return ret; 1734 } 1735 1736 if (!uvc_queue_streaming(&stream->queue)) 1737 return 0; 1738 1739 ret = uvc_init_video(stream, GFP_NOIO); 1740 if (ret < 0) 1741 uvc_queue_enable(&stream->queue, 0); 1742 1743 return ret; 1744 } 1745 1746 /* ------------------------------------------------------------------------ 1747 * Video device 1748 */ 1749 1750 /* 1751 * Initialize the UVC video device by switching to alternate setting 0 and 1752 * retrieve the default format. 1753 * 1754 * Some cameras (namely the Fuji Finepix) set the format and frame 1755 * indexes to zero. The UVC standard doesn't clearly make this a spec 1756 * violation, so try to silently fix the values if possible. 1757 * 1758 * This function is called before registering the device with V4L. 1759 */ 1760 int uvc_video_init(struct uvc_streaming *stream) 1761 { 1762 struct uvc_streaming_control *probe = &stream->ctrl; 1763 struct uvc_format *format = NULL; 1764 struct uvc_frame *frame = NULL; 1765 unsigned int i; 1766 int ret; 1767 1768 if (stream->nformats == 0) { 1769 uvc_printk(KERN_INFO, "No supported video formats found.\n"); 1770 return -EINVAL; 1771 } 1772 1773 atomic_set(&stream->active, 0); 1774 1775 /* Initialize the video buffers queue. */ 1776 ret = uvc_queue_init(&stream->queue, stream->type, !uvc_no_drop_param); 1777 if (ret) 1778 return ret; 1779 1780 /* Alternate setting 0 should be the default, yet the XBox Live Vision 1781 * Cam (and possibly other devices) crash or otherwise misbehave if 1782 * they don't receive a SET_INTERFACE request before any other video 1783 * control request. 1784 */ 1785 usb_set_interface(stream->dev->udev, stream->intfnum, 0); 1786 1787 /* Set the streaming probe control with default streaming parameters 1788 * retrieved from the device. Webcams that don't suport GET_DEF 1789 * requests on the probe control will just keep their current streaming 1790 * parameters. 1791 */ 1792 if (uvc_get_video_ctrl(stream, probe, 1, UVC_GET_DEF) == 0) 1793 uvc_set_video_ctrl(stream, probe, 1); 1794 1795 /* Initialize the streaming parameters with the probe control current 1796 * value. This makes sure SET_CUR requests on the streaming commit 1797 * control will always use values retrieved from a successful GET_CUR 1798 * request on the probe control, as required by the UVC specification. 1799 */ 1800 ret = uvc_get_video_ctrl(stream, probe, 1, UVC_GET_CUR); 1801 if (ret < 0) 1802 return ret; 1803 1804 /* Check if the default format descriptor exists. Use the first 1805 * available format otherwise. 1806 */ 1807 for (i = stream->nformats; i > 0; --i) { 1808 format = &stream->format[i-1]; 1809 if (format->index == probe->bFormatIndex) 1810 break; 1811 } 1812 1813 if (format->nframes == 0) { 1814 uvc_printk(KERN_INFO, "No frame descriptor found for the " 1815 "default format.\n"); 1816 return -EINVAL; 1817 } 1818 1819 /* Zero bFrameIndex might be correct. Stream-based formats (including 1820 * MPEG-2 TS and DV) do not support frames but have a dummy frame 1821 * descriptor with bFrameIndex set to zero. If the default frame 1822 * descriptor is not found, use the first available frame. 1823 */ 1824 for (i = format->nframes; i > 0; --i) { 1825 frame = &format->frame[i-1]; 1826 if (frame->bFrameIndex == probe->bFrameIndex) 1827 break; 1828 } 1829 1830 probe->bFormatIndex = format->index; 1831 probe->bFrameIndex = frame->bFrameIndex; 1832 1833 stream->def_format = format; 1834 stream->cur_format = format; 1835 stream->cur_frame = frame; 1836 1837 /* Select the video decoding function */ 1838 if (stream->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) { 1839 if (stream->dev->quirks & UVC_QUIRK_BUILTIN_ISIGHT) 1840 stream->decode = uvc_video_decode_isight; 1841 else if (stream->intf->num_altsetting > 1) 1842 stream->decode = uvc_video_decode_isoc; 1843 else 1844 stream->decode = uvc_video_decode_bulk; 1845 } else { 1846 if (stream->intf->num_altsetting == 1) 1847 stream->decode = uvc_video_encode_bulk; 1848 else { 1849 uvc_printk(KERN_INFO, "Isochronous endpoints are not " 1850 "supported for video output devices.\n"); 1851 return -EINVAL; 1852 } 1853 } 1854 1855 return 0; 1856 } 1857 1858 /* 1859 * Enable or disable the video stream. 1860 */ 1861 int uvc_video_enable(struct uvc_streaming *stream, int enable) 1862 { 1863 int ret; 1864 1865 if (!enable) { 1866 uvc_uninit_video(stream, 1); 1867 if (stream->intf->num_altsetting > 1) { 1868 usb_set_interface(stream->dev->udev, 1869 stream->intfnum, 0); 1870 } else { 1871 /* UVC doesn't specify how to inform a bulk-based device 1872 * when the video stream is stopped. Windows sends a 1873 * CLEAR_FEATURE(HALT) request to the video streaming 1874 * bulk endpoint, mimic the same behaviour. 1875 */ 1876 unsigned int epnum = stream->header.bEndpointAddress 1877 & USB_ENDPOINT_NUMBER_MASK; 1878 unsigned int dir = stream->header.bEndpointAddress 1879 & USB_ENDPOINT_DIR_MASK; 1880 unsigned int pipe; 1881 1882 pipe = usb_sndbulkpipe(stream->dev->udev, epnum) | dir; 1883 usb_clear_halt(stream->dev->udev, pipe); 1884 } 1885 1886 uvc_queue_enable(&stream->queue, 0); 1887 uvc_video_clock_cleanup(stream); 1888 return 0; 1889 } 1890 1891 ret = uvc_video_clock_init(stream); 1892 if (ret < 0) 1893 return ret; 1894 1895 ret = uvc_queue_enable(&stream->queue, 1); 1896 if (ret < 0) 1897 goto error_queue; 1898 1899 /* Commit the streaming parameters. */ 1900 ret = uvc_commit_video(stream, &stream->ctrl); 1901 if (ret < 0) 1902 goto error_commit; 1903 1904 ret = uvc_init_video(stream, GFP_KERNEL); 1905 if (ret < 0) 1906 goto error_video; 1907 1908 return 0; 1909 1910 error_video: 1911 usb_set_interface(stream->dev->udev, stream->intfnum, 0); 1912 error_commit: 1913 uvc_queue_enable(&stream->queue, 0); 1914 error_queue: 1915 uvc_video_clock_cleanup(stream); 1916 1917 return ret; 1918 } 1919