1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 */ 4 5 #include <linux/gfp.h> 6 #include <linux/init.h> 7 #include <linux/ratelimit.h> 8 #include <linux/usb.h> 9 #include <linux/usb/audio.h> 10 #include <linux/slab.h> 11 12 #include <sound/core.h> 13 #include <sound/pcm.h> 14 #include <sound/pcm_params.h> 15 16 #include "usbaudio.h" 17 #include "helper.h" 18 #include "card.h" 19 #include "endpoint.h" 20 #include "pcm.h" 21 #include "clock.h" 22 #include "quirks.h" 23 24 #define EP_FLAG_RUNNING 1 25 #define EP_FLAG_STOPPING 2 26 27 /* 28 * snd_usb_endpoint is a model that abstracts everything related to an 29 * USB endpoint and its streaming. 30 * 31 * There are functions to activate and deactivate the streaming URBs and 32 * optional callbacks to let the pcm logic handle the actual content of the 33 * packets for playback and record. Thus, the bus streaming and the audio 34 * handlers are fully decoupled. 35 * 36 * There are two different types of endpoints in audio applications. 37 * 38 * SND_USB_ENDPOINT_TYPE_DATA handles full audio data payload for both 39 * inbound and outbound traffic. 40 * 41 * SND_USB_ENDPOINT_TYPE_SYNC endpoints are for inbound traffic only and 42 * expect the payload to carry Q10.14 / Q16.16 formatted sync information 43 * (3 or 4 bytes). 44 * 45 * Each endpoint has to be configured prior to being used by calling 46 * snd_usb_endpoint_set_params(). 47 * 48 * The model incorporates a reference counting, so that multiple users 49 * can call snd_usb_endpoint_start() and snd_usb_endpoint_stop(), and 50 * only the first user will effectively start the URBs, and only the last 51 * one to stop it will tear the URBs down again. 52 */ 53 54 /* 55 * convert a sampling rate into our full speed format (fs/1000 in Q16.16) 56 * this will overflow at approx 524 kHz 57 */ 58 static inline unsigned get_usb_full_speed_rate(unsigned int rate) 59 { 60 return ((rate << 13) + 62) / 125; 61 } 62 63 /* 64 * convert a sampling rate into USB high speed format (fs/8000 in Q16.16) 65 * this will overflow at approx 4 MHz 66 */ 67 static inline unsigned get_usb_high_speed_rate(unsigned int rate) 68 { 69 return ((rate << 10) + 62) / 125; 70 } 71 72 /* 73 * release a urb data 74 */ 75 static void release_urb_ctx(struct snd_urb_ctx *u) 76 { 77 if (u->buffer_size) 78 usb_free_coherent(u->ep->chip->dev, u->buffer_size, 79 u->urb->transfer_buffer, 80 u->urb->transfer_dma); 81 usb_free_urb(u->urb); 82 u->urb = NULL; 83 } 84 85 static const char *usb_error_string(int err) 86 { 87 switch (err) { 88 case -ENODEV: 89 return "no device"; 90 case -ENOENT: 91 return "endpoint not enabled"; 92 case -EPIPE: 93 return "endpoint stalled"; 94 case -ENOSPC: 95 return "not enough bandwidth"; 96 case -ESHUTDOWN: 97 return "device disabled"; 98 case -EHOSTUNREACH: 99 return "device suspended"; 100 case -EINVAL: 101 case -EAGAIN: 102 case -EFBIG: 103 case -EMSGSIZE: 104 return "internal error"; 105 default: 106 return "unknown error"; 107 } 108 } 109 110 /** 111 * snd_usb_endpoint_implicit_feedback_sink: Report endpoint usage type 112 * 113 * @ep: The snd_usb_endpoint 114 * 115 * Determine whether an endpoint is driven by an implicit feedback 116 * data endpoint source. 117 */ 118 int snd_usb_endpoint_implicit_feedback_sink(struct snd_usb_endpoint *ep) 119 { 120 return ep->implicit_fb_sync && usb_pipeout(ep->pipe); 121 } 122 123 /* 124 * Return the number of samples to be sent in the next packet 125 * for streaming based on information derived from sync endpoints 126 * 127 * This won't be used for implicit feedback which takes the packet size 128 * returned from the sync source 129 */ 130 static int slave_next_packet_size(struct snd_usb_endpoint *ep) 131 { 132 unsigned long flags; 133 int ret; 134 135 if (ep->fill_max) 136 return ep->maxframesize; 137 138 spin_lock_irqsave(&ep->lock, flags); 139 ep->phase = (ep->phase & 0xffff) 140 + (ep->freqm << ep->datainterval); 141 ret = min(ep->phase >> 16, ep->maxframesize); 142 spin_unlock_irqrestore(&ep->lock, flags); 143 144 return ret; 145 } 146 147 /* 148 * Return the number of samples to be sent in the next packet 149 * for adaptive and synchronous endpoints 150 */ 151 static int next_packet_size(struct snd_usb_endpoint *ep) 152 { 153 int ret; 154 155 if (ep->fill_max) 156 return ep->maxframesize; 157 158 ep->sample_accum += ep->sample_rem; 159 if (ep->sample_accum >= ep->pps) { 160 ep->sample_accum -= ep->pps; 161 ret = ep->packsize[1]; 162 } else { 163 ret = ep->packsize[0]; 164 } 165 166 return ret; 167 } 168 169 /* 170 * snd_usb_endpoint_next_packet_size: Return the number of samples to be sent 171 * in the next packet 172 */ 173 int snd_usb_endpoint_next_packet_size(struct snd_usb_endpoint *ep, 174 struct snd_urb_ctx *ctx, int idx) 175 { 176 if (ctx->packet_size[idx]) 177 return ctx->packet_size[idx]; 178 else if (ep->sync_source) 179 return slave_next_packet_size(ep); 180 else 181 return next_packet_size(ep); 182 } 183 184 static void call_retire_callback(struct snd_usb_endpoint *ep, 185 struct urb *urb) 186 { 187 struct snd_usb_substream *data_subs; 188 189 data_subs = READ_ONCE(ep->data_subs); 190 if (data_subs && ep->retire_data_urb) 191 ep->retire_data_urb(data_subs, urb); 192 } 193 194 static void retire_outbound_urb(struct snd_usb_endpoint *ep, 195 struct snd_urb_ctx *urb_ctx) 196 { 197 call_retire_callback(ep, urb_ctx->urb); 198 } 199 200 static void snd_usb_handle_sync_urb(struct snd_usb_endpoint *ep, 201 struct snd_usb_endpoint *sender, 202 const struct urb *urb); 203 204 static void retire_inbound_urb(struct snd_usb_endpoint *ep, 205 struct snd_urb_ctx *urb_ctx) 206 { 207 struct urb *urb = urb_ctx->urb; 208 struct snd_usb_endpoint *sync_sink; 209 210 if (unlikely(ep->skip_packets > 0)) { 211 ep->skip_packets--; 212 return; 213 } 214 215 sync_sink = READ_ONCE(ep->sync_sink); 216 if (sync_sink) 217 snd_usb_handle_sync_urb(sync_sink, ep, urb); 218 219 call_retire_callback(ep, urb); 220 } 221 222 static void prepare_silent_urb(struct snd_usb_endpoint *ep, 223 struct snd_urb_ctx *ctx) 224 { 225 struct urb *urb = ctx->urb; 226 unsigned int offs = 0; 227 unsigned int extra = 0; 228 __le32 packet_length; 229 int i; 230 231 /* For tx_length_quirk, put packet length at start of packet */ 232 if (ep->chip->tx_length_quirk) 233 extra = sizeof(packet_length); 234 235 for (i = 0; i < ctx->packets; ++i) { 236 unsigned int offset; 237 unsigned int length; 238 int counts; 239 240 counts = snd_usb_endpoint_next_packet_size(ep, ctx, i); 241 length = counts * ep->stride; /* number of silent bytes */ 242 offset = offs * ep->stride + extra * i; 243 urb->iso_frame_desc[i].offset = offset; 244 urb->iso_frame_desc[i].length = length + extra; 245 if (extra) { 246 packet_length = cpu_to_le32(length); 247 memcpy(urb->transfer_buffer + offset, 248 &packet_length, sizeof(packet_length)); 249 } 250 memset(urb->transfer_buffer + offset + extra, 251 ep->silence_value, length); 252 offs += counts; 253 } 254 255 urb->number_of_packets = ctx->packets; 256 urb->transfer_buffer_length = offs * ep->stride + ctx->packets * extra; 257 } 258 259 /* 260 * Prepare a PLAYBACK urb for submission to the bus. 261 */ 262 static void prepare_outbound_urb(struct snd_usb_endpoint *ep, 263 struct snd_urb_ctx *ctx) 264 { 265 struct urb *urb = ctx->urb; 266 unsigned char *cp = urb->transfer_buffer; 267 struct snd_usb_substream *data_subs; 268 269 urb->dev = ep->chip->dev; /* we need to set this at each time */ 270 271 switch (ep->type) { 272 case SND_USB_ENDPOINT_TYPE_DATA: 273 data_subs = READ_ONCE(ep->data_subs); 274 if (data_subs && ep->prepare_data_urb) 275 ep->prepare_data_urb(data_subs, urb); 276 else /* no data provider, so send silence */ 277 prepare_silent_urb(ep, ctx); 278 break; 279 280 case SND_USB_ENDPOINT_TYPE_SYNC: 281 if (snd_usb_get_speed(ep->chip->dev) >= USB_SPEED_HIGH) { 282 /* 283 * fill the length and offset of each urb descriptor. 284 * the fixed 12.13 frequency is passed as 16.16 through the pipe. 285 */ 286 urb->iso_frame_desc[0].length = 4; 287 urb->iso_frame_desc[0].offset = 0; 288 cp[0] = ep->freqn; 289 cp[1] = ep->freqn >> 8; 290 cp[2] = ep->freqn >> 16; 291 cp[3] = ep->freqn >> 24; 292 } else { 293 /* 294 * fill the length and offset of each urb descriptor. 295 * the fixed 10.14 frequency is passed through the pipe. 296 */ 297 urb->iso_frame_desc[0].length = 3; 298 urb->iso_frame_desc[0].offset = 0; 299 cp[0] = ep->freqn >> 2; 300 cp[1] = ep->freqn >> 10; 301 cp[2] = ep->freqn >> 18; 302 } 303 304 break; 305 } 306 } 307 308 /* 309 * Prepare a CAPTURE or SYNC urb for submission to the bus. 310 */ 311 static inline void prepare_inbound_urb(struct snd_usb_endpoint *ep, 312 struct snd_urb_ctx *urb_ctx) 313 { 314 int i, offs; 315 struct urb *urb = urb_ctx->urb; 316 317 urb->dev = ep->chip->dev; /* we need to set this at each time */ 318 319 switch (ep->type) { 320 case SND_USB_ENDPOINT_TYPE_DATA: 321 offs = 0; 322 for (i = 0; i < urb_ctx->packets; i++) { 323 urb->iso_frame_desc[i].offset = offs; 324 urb->iso_frame_desc[i].length = ep->curpacksize; 325 offs += ep->curpacksize; 326 } 327 328 urb->transfer_buffer_length = offs; 329 urb->number_of_packets = urb_ctx->packets; 330 break; 331 332 case SND_USB_ENDPOINT_TYPE_SYNC: 333 urb->iso_frame_desc[0].length = min(4u, ep->syncmaxsize); 334 urb->iso_frame_desc[0].offset = 0; 335 break; 336 } 337 } 338 339 /* notify an error as XRUN to the assigned PCM data substream */ 340 static void notify_xrun(struct snd_usb_endpoint *ep) 341 { 342 struct snd_usb_substream *data_subs; 343 344 data_subs = READ_ONCE(ep->data_subs); 345 if (data_subs && data_subs->pcm_substream) 346 snd_pcm_stop_xrun(data_subs->pcm_substream); 347 } 348 349 static struct snd_usb_packet_info * 350 next_packet_fifo_enqueue(struct snd_usb_endpoint *ep) 351 { 352 struct snd_usb_packet_info *p; 353 354 p = ep->next_packet + (ep->next_packet_head + ep->next_packet_queued) % 355 ARRAY_SIZE(ep->next_packet); 356 ep->next_packet_queued++; 357 return p; 358 } 359 360 static struct snd_usb_packet_info * 361 next_packet_fifo_dequeue(struct snd_usb_endpoint *ep) 362 { 363 struct snd_usb_packet_info *p; 364 365 p = ep->next_packet + ep->next_packet_head; 366 ep->next_packet_head++; 367 ep->next_packet_head %= ARRAY_SIZE(ep->next_packet); 368 ep->next_packet_queued--; 369 return p; 370 } 371 372 /* 373 * Send output urbs that have been prepared previously. URBs are dequeued 374 * from ep->ready_playback_urbs and in case there aren't any available 375 * or there are no packets that have been prepared, this function does 376 * nothing. 377 * 378 * The reason why the functionality of sending and preparing URBs is separated 379 * is that host controllers don't guarantee the order in which they return 380 * inbound and outbound packets to their submitters. 381 * 382 * This function is only used for implicit feedback endpoints. For endpoints 383 * driven by dedicated sync endpoints, URBs are immediately re-submitted 384 * from their completion handler. 385 */ 386 static void queue_pending_output_urbs(struct snd_usb_endpoint *ep) 387 { 388 while (test_bit(EP_FLAG_RUNNING, &ep->flags)) { 389 390 unsigned long flags; 391 struct snd_usb_packet_info *packet; 392 struct snd_urb_ctx *ctx = NULL; 393 int err, i; 394 395 spin_lock_irqsave(&ep->lock, flags); 396 if (ep->next_packet_queued > 0 && 397 !list_empty(&ep->ready_playback_urbs)) { 398 /* take URB out of FIFO */ 399 ctx = list_first_entry(&ep->ready_playback_urbs, 400 struct snd_urb_ctx, ready_list); 401 list_del_init(&ctx->ready_list); 402 403 packet = next_packet_fifo_dequeue(ep); 404 } 405 spin_unlock_irqrestore(&ep->lock, flags); 406 407 if (ctx == NULL) 408 return; 409 410 /* copy over the length information */ 411 for (i = 0; i < packet->packets; i++) 412 ctx->packet_size[i] = packet->packet_size[i]; 413 414 /* call the data handler to fill in playback data */ 415 prepare_outbound_urb(ep, ctx); 416 417 err = usb_submit_urb(ctx->urb, GFP_ATOMIC); 418 if (err < 0) { 419 usb_audio_err(ep->chip, 420 "Unable to submit urb #%d: %d at %s\n", 421 ctx->index, err, __func__); 422 notify_xrun(ep); 423 return; 424 } 425 426 set_bit(ctx->index, &ep->active_mask); 427 } 428 } 429 430 /* 431 * complete callback for urbs 432 */ 433 static void snd_complete_urb(struct urb *urb) 434 { 435 struct snd_urb_ctx *ctx = urb->context; 436 struct snd_usb_endpoint *ep = ctx->ep; 437 unsigned long flags; 438 int err; 439 440 if (unlikely(urb->status == -ENOENT || /* unlinked */ 441 urb->status == -ENODEV || /* device removed */ 442 urb->status == -ECONNRESET || /* unlinked */ 443 urb->status == -ESHUTDOWN)) /* device disabled */ 444 goto exit_clear; 445 /* device disconnected */ 446 if (unlikely(atomic_read(&ep->chip->shutdown))) 447 goto exit_clear; 448 449 if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags))) 450 goto exit_clear; 451 452 if (usb_pipeout(ep->pipe)) { 453 retire_outbound_urb(ep, ctx); 454 /* can be stopped during retire callback */ 455 if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags))) 456 goto exit_clear; 457 458 if (snd_usb_endpoint_implicit_feedback_sink(ep)) { 459 spin_lock_irqsave(&ep->lock, flags); 460 list_add_tail(&ctx->ready_list, &ep->ready_playback_urbs); 461 clear_bit(ctx->index, &ep->active_mask); 462 spin_unlock_irqrestore(&ep->lock, flags); 463 queue_pending_output_urbs(ep); 464 return; 465 } 466 467 prepare_outbound_urb(ep, ctx); 468 /* can be stopped during prepare callback */ 469 if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags))) 470 goto exit_clear; 471 } else { 472 retire_inbound_urb(ep, ctx); 473 /* can be stopped during retire callback */ 474 if (unlikely(!test_bit(EP_FLAG_RUNNING, &ep->flags))) 475 goto exit_clear; 476 477 prepare_inbound_urb(ep, ctx); 478 } 479 480 err = usb_submit_urb(urb, GFP_ATOMIC); 481 if (err == 0) 482 return; 483 484 usb_audio_err(ep->chip, "cannot submit urb (err = %d)\n", err); 485 notify_xrun(ep); 486 487 exit_clear: 488 clear_bit(ctx->index, &ep->active_mask); 489 } 490 491 /* 492 * Get the existing endpoint object corresponding EP 493 * Returns NULL if not present. 494 */ 495 struct snd_usb_endpoint * 496 snd_usb_get_endpoint(struct snd_usb_audio *chip, int ep_num) 497 { 498 struct snd_usb_endpoint *ep; 499 500 list_for_each_entry(ep, &chip->ep_list, list) { 501 if (ep->ep_num == ep_num) 502 return ep; 503 } 504 505 return NULL; 506 } 507 508 #define ep_type_name(type) \ 509 (type == SND_USB_ENDPOINT_TYPE_DATA ? "data" : "sync") 510 511 /** 512 * snd_usb_add_endpoint: Add an endpoint to an USB audio chip 513 * 514 * @chip: The chip 515 * @ep_num: The number of the endpoint to use 516 * @type: SND_USB_ENDPOINT_TYPE_DATA or SND_USB_ENDPOINT_TYPE_SYNC 517 * 518 * If the requested endpoint has not been added to the given chip before, 519 * a new instance is created. 520 * 521 * Returns zero on success or a negative error code. 522 * 523 * New endpoints will be added to chip->ep_list and must be freed by 524 * calling snd_usb_endpoint_free(). 525 * 526 * For SND_USB_ENDPOINT_TYPE_SYNC, the caller needs to guarantee that 527 * bNumEndpoints > 1 beforehand. 528 */ 529 int snd_usb_add_endpoint(struct snd_usb_audio *chip, int ep_num, int type) 530 { 531 struct snd_usb_endpoint *ep; 532 bool is_playback; 533 534 ep = snd_usb_get_endpoint(chip, ep_num); 535 if (ep) 536 return 0; 537 538 usb_audio_dbg(chip, "Creating new %s endpoint #%x\n", 539 ep_type_name(type), 540 ep_num); 541 ep = kzalloc(sizeof(*ep), GFP_KERNEL); 542 if (!ep) 543 return -ENOMEM; 544 545 ep->chip = chip; 546 spin_lock_init(&ep->lock); 547 ep->type = type; 548 ep->ep_num = ep_num; 549 INIT_LIST_HEAD(&ep->ready_playback_urbs); 550 551 is_playback = ((ep_num & USB_ENDPOINT_DIR_MASK) == USB_DIR_OUT); 552 ep_num &= USB_ENDPOINT_NUMBER_MASK; 553 if (is_playback) 554 ep->pipe = usb_sndisocpipe(chip->dev, ep_num); 555 else 556 ep->pipe = usb_rcvisocpipe(chip->dev, ep_num); 557 558 list_add_tail(&ep->list, &chip->ep_list); 559 return 0; 560 } 561 562 /* Set up syncinterval and maxsyncsize for a sync EP */ 563 static void endpoint_set_syncinterval(struct snd_usb_audio *chip, 564 struct snd_usb_endpoint *ep) 565 { 566 struct usb_host_interface *alts; 567 struct usb_endpoint_descriptor *desc; 568 569 alts = snd_usb_get_host_interface(chip, ep->iface, ep->altsetting); 570 if (!alts) 571 return; 572 573 desc = get_endpoint(alts, ep->ep_idx); 574 if (desc->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE && 575 desc->bRefresh >= 1 && desc->bRefresh <= 9) 576 ep->syncinterval = desc->bRefresh; 577 else if (snd_usb_get_speed(chip->dev) == USB_SPEED_FULL) 578 ep->syncinterval = 1; 579 else if (desc->bInterval >= 1 && desc->bInterval <= 16) 580 ep->syncinterval = desc->bInterval - 1; 581 else 582 ep->syncinterval = 3; 583 584 ep->syncmaxsize = le16_to_cpu(desc->wMaxPacketSize); 585 } 586 587 static bool endpoint_compatible(struct snd_usb_endpoint *ep, 588 const struct audioformat *fp, 589 const struct snd_pcm_hw_params *params) 590 { 591 if (!ep->opened) 592 return false; 593 if (ep->cur_audiofmt != fp) 594 return false; 595 if (ep->cur_rate != params_rate(params) || 596 ep->cur_format != params_format(params) || 597 ep->cur_period_frames != params_period_size(params) || 598 ep->cur_buffer_periods != params_periods(params)) 599 return false; 600 return true; 601 } 602 603 /* 604 * Check whether the given fp and hw params are compatbile with the current 605 * setup of the target EP for implicit feedback sync 606 */ 607 bool snd_usb_endpoint_compatible(struct snd_usb_audio *chip, 608 struct snd_usb_endpoint *ep, 609 const struct audioformat *fp, 610 const struct snd_pcm_hw_params *params) 611 { 612 bool ret; 613 614 mutex_lock(&chip->mutex); 615 ret = endpoint_compatible(ep, fp, params); 616 mutex_unlock(&chip->mutex); 617 return ret; 618 } 619 620 /* 621 * snd_usb_endpoint_open: Open the endpoint 622 * 623 * Called from hw_params to assign the endpoint to the substream. 624 * It's reference-counted, and only the first opener is allowed to set up 625 * arbitrary parameters. The later opener must be compatible with the 626 * former opened parameters. 627 * The endpoint needs to be closed via snd_usb_endpoint_close() later. 628 * 629 * Note that this function doesn't configure the endpoint. The substream 630 * needs to set it up later via snd_usb_endpoint_configure(). 631 */ 632 struct snd_usb_endpoint * 633 snd_usb_endpoint_open(struct snd_usb_audio *chip, 634 const struct audioformat *fp, 635 const struct snd_pcm_hw_params *params, 636 bool is_sync_ep) 637 { 638 struct snd_usb_endpoint *ep; 639 int ep_num = is_sync_ep ? fp->sync_ep : fp->endpoint; 640 641 mutex_lock(&chip->mutex); 642 ep = snd_usb_get_endpoint(chip, ep_num); 643 if (!ep) { 644 usb_audio_err(chip, "Cannot find EP 0x%x to open\n", ep_num); 645 goto unlock; 646 } 647 648 if (!ep->opened) { 649 if (is_sync_ep) { 650 ep->iface = fp->sync_iface; 651 ep->altsetting = fp->sync_altsetting; 652 ep->ep_idx = fp->sync_ep_idx; 653 } else { 654 ep->iface = fp->iface; 655 ep->altsetting = fp->altsetting; 656 ep->ep_idx = 0; 657 } 658 usb_audio_dbg(chip, "Open EP 0x%x, iface=%d:%d, idx=%d\n", 659 ep_num, ep->iface, ep->altsetting, ep->ep_idx); 660 661 ep->cur_audiofmt = fp; 662 ep->cur_channels = fp->channels; 663 ep->cur_rate = params_rate(params); 664 ep->cur_format = params_format(params); 665 ep->cur_frame_bytes = snd_pcm_format_physical_width(ep->cur_format) * 666 ep->cur_channels / 8; 667 ep->cur_period_frames = params_period_size(params); 668 ep->cur_period_bytes = ep->cur_period_frames * ep->cur_frame_bytes; 669 ep->cur_buffer_periods = params_periods(params); 670 671 if (ep->type == SND_USB_ENDPOINT_TYPE_SYNC) 672 endpoint_set_syncinterval(chip, ep); 673 674 ep->implicit_fb_sync = fp->implicit_fb; 675 ep->need_setup = true; 676 677 usb_audio_dbg(chip, " channels=%d, rate=%d, format=%s, period_bytes=%d, periods=%d, implicit_fb=%d\n", 678 ep->cur_channels, ep->cur_rate, 679 snd_pcm_format_name(ep->cur_format), 680 ep->cur_period_bytes, ep->cur_buffer_periods, 681 ep->implicit_fb_sync); 682 683 } else { 684 if (!endpoint_compatible(ep, fp, params)) { 685 usb_audio_err(chip, "Incompatible EP setup for 0x%x\n", 686 ep_num); 687 ep = NULL; 688 goto unlock; 689 } 690 691 usb_audio_dbg(chip, "Reopened EP 0x%x (count %d)\n", 692 ep_num, ep->opened); 693 } 694 695 ep->opened++; 696 697 unlock: 698 mutex_unlock(&chip->mutex); 699 return ep; 700 } 701 702 /* 703 * snd_usb_endpoint_set_sync: Link data and sync endpoints 704 * 705 * Pass NULL to sync_ep to unlink again 706 */ 707 void snd_usb_endpoint_set_sync(struct snd_usb_audio *chip, 708 struct snd_usb_endpoint *data_ep, 709 struct snd_usb_endpoint *sync_ep) 710 { 711 data_ep->sync_source = sync_ep; 712 } 713 714 /* 715 * Set data endpoint callbacks and the assigned data stream 716 * 717 * Called at PCM trigger and cleanups. 718 * Pass NULL to deactivate each callback. 719 */ 720 void snd_usb_endpoint_set_callback(struct snd_usb_endpoint *ep, 721 void (*prepare)(struct snd_usb_substream *subs, 722 struct urb *urb), 723 void (*retire)(struct snd_usb_substream *subs, 724 struct urb *urb), 725 struct snd_usb_substream *data_subs) 726 { 727 ep->prepare_data_urb = prepare; 728 ep->retire_data_urb = retire; 729 WRITE_ONCE(ep->data_subs, data_subs); 730 } 731 732 static int endpoint_set_interface(struct snd_usb_audio *chip, 733 struct snd_usb_endpoint *ep, 734 bool set) 735 { 736 int altset = set ? ep->altsetting : 0; 737 int err; 738 739 usb_audio_dbg(chip, "Setting usb interface %d:%d for EP 0x%x\n", 740 ep->iface, altset, ep->ep_num); 741 err = usb_set_interface(chip->dev, ep->iface, altset); 742 if (err < 0) { 743 usb_audio_err(chip, "%d:%d: usb_set_interface failed (%d)\n", 744 ep->iface, altset, err); 745 return err; 746 } 747 748 snd_usb_set_interface_quirk(chip); 749 return 0; 750 } 751 752 /* 753 * snd_usb_endpoint_close: Close the endpoint 754 * 755 * Unreference the already opened endpoint via snd_usb_endpoint_open(). 756 */ 757 void snd_usb_endpoint_close(struct snd_usb_audio *chip, 758 struct snd_usb_endpoint *ep) 759 { 760 mutex_lock(&chip->mutex); 761 usb_audio_dbg(chip, "Closing EP 0x%x (count %d)\n", 762 ep->ep_num, ep->opened); 763 if (!--ep->opened) { 764 endpoint_set_interface(chip, ep, false); 765 ep->iface = 0; 766 ep->altsetting = 0; 767 ep->cur_audiofmt = NULL; 768 ep->cur_rate = 0; 769 usb_audio_dbg(chip, "EP 0x%x closed\n", ep->ep_num); 770 } 771 mutex_unlock(&chip->mutex); 772 } 773 774 /* Prepare for suspening EP, called from the main suspend handler */ 775 void snd_usb_endpoint_suspend(struct snd_usb_endpoint *ep) 776 { 777 ep->need_setup = true; 778 } 779 780 /* 781 * wait until all urbs are processed. 782 */ 783 static int wait_clear_urbs(struct snd_usb_endpoint *ep) 784 { 785 unsigned long end_time = jiffies + msecs_to_jiffies(1000); 786 int alive; 787 788 if (!test_bit(EP_FLAG_STOPPING, &ep->flags)) 789 return 0; 790 791 do { 792 alive = bitmap_weight(&ep->active_mask, ep->nurbs); 793 if (!alive) 794 break; 795 796 schedule_timeout_uninterruptible(1); 797 } while (time_before(jiffies, end_time)); 798 799 if (alive) 800 usb_audio_err(ep->chip, 801 "timeout: still %d active urbs on EP #%x\n", 802 alive, ep->ep_num); 803 clear_bit(EP_FLAG_STOPPING, &ep->flags); 804 805 ep->sync_sink = NULL; 806 snd_usb_endpoint_set_callback(ep, NULL, NULL, NULL); 807 808 return 0; 809 } 810 811 /* sync the pending stop operation; 812 * this function itself doesn't trigger the stop operation 813 */ 814 void snd_usb_endpoint_sync_pending_stop(struct snd_usb_endpoint *ep) 815 { 816 if (ep) 817 wait_clear_urbs(ep); 818 } 819 820 /* 821 * Stop and unlink active urbs. 822 * 823 * This function checks and clears EP_FLAG_RUNNING state. 824 * When @wait_sync is set, it waits until all pending URBs are killed. 825 */ 826 static int stop_and_unlink_urbs(struct snd_usb_endpoint *ep, bool force, 827 bool wait_sync) 828 { 829 unsigned int i; 830 831 if (!force && atomic_read(&ep->chip->shutdown)) /* to be sure... */ 832 return -EBADFD; 833 834 if (atomic_read(&ep->running)) 835 return -EBUSY; 836 837 if (!test_and_clear_bit(EP_FLAG_RUNNING, &ep->flags)) 838 goto out; 839 840 set_bit(EP_FLAG_STOPPING, &ep->flags); 841 INIT_LIST_HEAD(&ep->ready_playback_urbs); 842 ep->next_packet_head = 0; 843 ep->next_packet_queued = 0; 844 845 for (i = 0; i < ep->nurbs; i++) { 846 if (test_bit(i, &ep->active_mask)) { 847 if (!test_and_set_bit(i, &ep->unlink_mask)) { 848 struct urb *u = ep->urb[i].urb; 849 usb_unlink_urb(u); 850 } 851 } 852 } 853 854 out: 855 if (wait_sync) 856 return wait_clear_urbs(ep); 857 return 0; 858 } 859 860 /* 861 * release an endpoint's urbs 862 */ 863 static void release_urbs(struct snd_usb_endpoint *ep, int force) 864 { 865 int i; 866 867 /* route incoming urbs to nirvana */ 868 snd_usb_endpoint_set_callback(ep, NULL, NULL, NULL); 869 870 /* stop urbs */ 871 stop_and_unlink_urbs(ep, force, true); 872 873 for (i = 0; i < ep->nurbs; i++) 874 release_urb_ctx(&ep->urb[i]); 875 876 usb_free_coherent(ep->chip->dev, SYNC_URBS * 4, 877 ep->syncbuf, ep->sync_dma); 878 879 ep->syncbuf = NULL; 880 ep->nurbs = 0; 881 } 882 883 /* 884 * configure a data endpoint 885 */ 886 static int data_ep_set_params(struct snd_usb_endpoint *ep) 887 { 888 struct snd_usb_audio *chip = ep->chip; 889 unsigned int maxsize, minsize, packs_per_ms, max_packs_per_urb; 890 unsigned int max_packs_per_period, urbs_per_period, urb_packs; 891 unsigned int max_urbs, i; 892 const struct audioformat *fmt = ep->cur_audiofmt; 893 int frame_bits = ep->cur_frame_bytes * 8; 894 int tx_length_quirk = (chip->tx_length_quirk && 895 usb_pipeout(ep->pipe)); 896 897 usb_audio_dbg(chip, "Setting params for data EP 0x%x, pipe 0x%x\n", 898 ep->ep_num, ep->pipe); 899 900 if (ep->cur_format == SNDRV_PCM_FORMAT_DSD_U16_LE && fmt->dsd_dop) { 901 /* 902 * When operating in DSD DOP mode, the size of a sample frame 903 * in hardware differs from the actual physical format width 904 * because we need to make room for the DOP markers. 905 */ 906 frame_bits += ep->cur_channels << 3; 907 } 908 909 ep->datainterval = fmt->datainterval; 910 ep->stride = frame_bits >> 3; 911 912 switch (ep->cur_format) { 913 case SNDRV_PCM_FORMAT_U8: 914 ep->silence_value = 0x80; 915 break; 916 case SNDRV_PCM_FORMAT_DSD_U8: 917 case SNDRV_PCM_FORMAT_DSD_U16_LE: 918 case SNDRV_PCM_FORMAT_DSD_U32_LE: 919 case SNDRV_PCM_FORMAT_DSD_U16_BE: 920 case SNDRV_PCM_FORMAT_DSD_U32_BE: 921 ep->silence_value = 0x69; 922 break; 923 default: 924 ep->silence_value = 0; 925 } 926 927 /* assume max. frequency is 50% higher than nominal */ 928 ep->freqmax = ep->freqn + (ep->freqn >> 1); 929 /* Round up freqmax to nearest integer in order to calculate maximum 930 * packet size, which must represent a whole number of frames. 931 * This is accomplished by adding 0x0.ffff before converting the 932 * Q16.16 format into integer. 933 * In order to accurately calculate the maximum packet size when 934 * the data interval is more than 1 (i.e. ep->datainterval > 0), 935 * multiply by the data interval prior to rounding. For instance, 936 * a freqmax of 41 kHz will result in a max packet size of 6 (5.125) 937 * frames with a data interval of 1, but 11 (10.25) frames with a 938 * data interval of 2. 939 * (ep->freqmax << ep->datainterval overflows at 8.192 MHz for the 940 * maximum datainterval value of 3, at USB full speed, higher for 941 * USB high speed, noting that ep->freqmax is in units of 942 * frames per packet in Q16.16 format.) 943 */ 944 maxsize = (((ep->freqmax << ep->datainterval) + 0xffff) >> 16) * 945 (frame_bits >> 3); 946 if (tx_length_quirk) 947 maxsize += sizeof(__le32); /* Space for length descriptor */ 948 /* but wMaxPacketSize might reduce this */ 949 if (ep->maxpacksize && ep->maxpacksize < maxsize) { 950 /* whatever fits into a max. size packet */ 951 unsigned int data_maxsize = maxsize = ep->maxpacksize; 952 953 if (tx_length_quirk) 954 /* Need to remove the length descriptor to calc freq */ 955 data_maxsize -= sizeof(__le32); 956 ep->freqmax = (data_maxsize / (frame_bits >> 3)) 957 << (16 - ep->datainterval); 958 } 959 960 if (ep->fill_max) 961 ep->curpacksize = ep->maxpacksize; 962 else 963 ep->curpacksize = maxsize; 964 965 if (snd_usb_get_speed(chip->dev) != USB_SPEED_FULL) { 966 packs_per_ms = 8 >> ep->datainterval; 967 max_packs_per_urb = MAX_PACKS_HS; 968 } else { 969 packs_per_ms = 1; 970 max_packs_per_urb = MAX_PACKS; 971 } 972 if (ep->sync_source && !ep->implicit_fb_sync) 973 max_packs_per_urb = min(max_packs_per_urb, 974 1U << ep->sync_source->syncinterval); 975 max_packs_per_urb = max(1u, max_packs_per_urb >> ep->datainterval); 976 977 /* 978 * Capture endpoints need to use small URBs because there's no way 979 * to tell in advance where the next period will end, and we don't 980 * want the next URB to complete much after the period ends. 981 * 982 * Playback endpoints with implicit sync much use the same parameters 983 * as their corresponding capture endpoint. 984 */ 985 if (usb_pipein(ep->pipe) || ep->implicit_fb_sync) { 986 987 urb_packs = packs_per_ms; 988 /* 989 * Wireless devices can poll at a max rate of once per 4ms. 990 * For dataintervals less than 5, increase the packet count to 991 * allow the host controller to use bursting to fill in the 992 * gaps. 993 */ 994 if (snd_usb_get_speed(chip->dev) == USB_SPEED_WIRELESS) { 995 int interval = ep->datainterval; 996 while (interval < 5) { 997 urb_packs <<= 1; 998 ++interval; 999 } 1000 } 1001 /* make capture URBs <= 1 ms and smaller than a period */ 1002 urb_packs = min(max_packs_per_urb, urb_packs); 1003 while (urb_packs > 1 && urb_packs * maxsize >= ep->cur_period_bytes) 1004 urb_packs >>= 1; 1005 ep->nurbs = MAX_URBS; 1006 1007 /* 1008 * Playback endpoints without implicit sync are adjusted so that 1009 * a period fits as evenly as possible in the smallest number of 1010 * URBs. The total number of URBs is adjusted to the size of the 1011 * ALSA buffer, subject to the MAX_URBS and MAX_QUEUE limits. 1012 */ 1013 } else { 1014 /* determine how small a packet can be */ 1015 minsize = (ep->freqn >> (16 - ep->datainterval)) * 1016 (frame_bits >> 3); 1017 /* with sync from device, assume it can be 12% lower */ 1018 if (ep->sync_source) 1019 minsize -= minsize >> 3; 1020 minsize = max(minsize, 1u); 1021 1022 /* how many packets will contain an entire ALSA period? */ 1023 max_packs_per_period = DIV_ROUND_UP(ep->cur_period_bytes, minsize); 1024 1025 /* how many URBs will contain a period? */ 1026 urbs_per_period = DIV_ROUND_UP(max_packs_per_period, 1027 max_packs_per_urb); 1028 /* how many packets are needed in each URB? */ 1029 urb_packs = DIV_ROUND_UP(max_packs_per_period, urbs_per_period); 1030 1031 /* limit the number of frames in a single URB */ 1032 ep->max_urb_frames = DIV_ROUND_UP(ep->cur_period_frames, 1033 urbs_per_period); 1034 1035 /* try to use enough URBs to contain an entire ALSA buffer */ 1036 max_urbs = min((unsigned) MAX_URBS, 1037 MAX_QUEUE * packs_per_ms / urb_packs); 1038 ep->nurbs = min(max_urbs, urbs_per_period * ep->cur_buffer_periods); 1039 } 1040 1041 /* allocate and initialize data urbs */ 1042 for (i = 0; i < ep->nurbs; i++) { 1043 struct snd_urb_ctx *u = &ep->urb[i]; 1044 u->index = i; 1045 u->ep = ep; 1046 u->packets = urb_packs; 1047 u->buffer_size = maxsize * u->packets; 1048 1049 if (fmt->fmt_type == UAC_FORMAT_TYPE_II) 1050 u->packets++; /* for transfer delimiter */ 1051 u->urb = usb_alloc_urb(u->packets, GFP_KERNEL); 1052 if (!u->urb) 1053 goto out_of_memory; 1054 1055 u->urb->transfer_buffer = 1056 usb_alloc_coherent(chip->dev, u->buffer_size, 1057 GFP_KERNEL, &u->urb->transfer_dma); 1058 if (!u->urb->transfer_buffer) 1059 goto out_of_memory; 1060 u->urb->pipe = ep->pipe; 1061 u->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP; 1062 u->urb->interval = 1 << ep->datainterval; 1063 u->urb->context = u; 1064 u->urb->complete = snd_complete_urb; 1065 INIT_LIST_HEAD(&u->ready_list); 1066 } 1067 1068 return 0; 1069 1070 out_of_memory: 1071 release_urbs(ep, 0); 1072 return -ENOMEM; 1073 } 1074 1075 /* 1076 * configure a sync endpoint 1077 */ 1078 static int sync_ep_set_params(struct snd_usb_endpoint *ep) 1079 { 1080 struct snd_usb_audio *chip = ep->chip; 1081 int i; 1082 1083 usb_audio_dbg(chip, "Setting params for sync EP 0x%x, pipe 0x%x\n", 1084 ep->ep_num, ep->pipe); 1085 1086 ep->syncbuf = usb_alloc_coherent(chip->dev, SYNC_URBS * 4, 1087 GFP_KERNEL, &ep->sync_dma); 1088 if (!ep->syncbuf) 1089 return -ENOMEM; 1090 1091 for (i = 0; i < SYNC_URBS; i++) { 1092 struct snd_urb_ctx *u = &ep->urb[i]; 1093 u->index = i; 1094 u->ep = ep; 1095 u->packets = 1; 1096 u->urb = usb_alloc_urb(1, GFP_KERNEL); 1097 if (!u->urb) 1098 goto out_of_memory; 1099 u->urb->transfer_buffer = ep->syncbuf + i * 4; 1100 u->urb->transfer_dma = ep->sync_dma + i * 4; 1101 u->urb->transfer_buffer_length = 4; 1102 u->urb->pipe = ep->pipe; 1103 u->urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP; 1104 u->urb->number_of_packets = 1; 1105 u->urb->interval = 1 << ep->syncinterval; 1106 u->urb->context = u; 1107 u->urb->complete = snd_complete_urb; 1108 } 1109 1110 ep->nurbs = SYNC_URBS; 1111 1112 return 0; 1113 1114 out_of_memory: 1115 release_urbs(ep, 0); 1116 return -ENOMEM; 1117 } 1118 1119 /* 1120 * snd_usb_endpoint_set_params: configure an snd_usb_endpoint 1121 * 1122 * Determine the number of URBs to be used on this endpoint. 1123 * An endpoint must be configured before it can be started. 1124 * An endpoint that is already running can not be reconfigured. 1125 */ 1126 static int snd_usb_endpoint_set_params(struct snd_usb_audio *chip, 1127 struct snd_usb_endpoint *ep) 1128 { 1129 const struct audioformat *fmt = ep->cur_audiofmt; 1130 int err; 1131 1132 /* release old buffers, if any */ 1133 release_urbs(ep, 0); 1134 1135 ep->datainterval = fmt->datainterval; 1136 ep->maxpacksize = fmt->maxpacksize; 1137 ep->fill_max = !!(fmt->attributes & UAC_EP_CS_ATTR_FILL_MAX); 1138 1139 if (snd_usb_get_speed(chip->dev) == USB_SPEED_FULL) { 1140 ep->freqn = get_usb_full_speed_rate(ep->cur_rate); 1141 ep->pps = 1000 >> ep->datainterval; 1142 } else { 1143 ep->freqn = get_usb_high_speed_rate(ep->cur_rate); 1144 ep->pps = 8000 >> ep->datainterval; 1145 } 1146 1147 ep->sample_rem = ep->cur_rate % ep->pps; 1148 ep->packsize[0] = ep->cur_rate / ep->pps; 1149 ep->packsize[1] = (ep->cur_rate + (ep->pps - 1)) / ep->pps; 1150 1151 /* calculate the frequency in 16.16 format */ 1152 ep->freqm = ep->freqn; 1153 ep->freqshift = INT_MIN; 1154 1155 ep->phase = 0; 1156 1157 switch (ep->type) { 1158 case SND_USB_ENDPOINT_TYPE_DATA: 1159 err = data_ep_set_params(ep); 1160 break; 1161 case SND_USB_ENDPOINT_TYPE_SYNC: 1162 err = sync_ep_set_params(ep); 1163 break; 1164 default: 1165 err = -EINVAL; 1166 } 1167 1168 usb_audio_dbg(chip, "Set up %d URBS, ret=%d\n", ep->nurbs, err); 1169 1170 if (err < 0) 1171 return err; 1172 1173 /* some unit conversions in runtime */ 1174 ep->maxframesize = ep->maxpacksize / ep->cur_frame_bytes; 1175 ep->curframesize = ep->curpacksize / ep->cur_frame_bytes; 1176 1177 return 0; 1178 } 1179 1180 /* 1181 * snd_usb_endpoint_configure: Configure the endpoint 1182 * 1183 * This function sets up the EP to be fully usable state. 1184 * It's called either from hw_params or prepare callback. 1185 * The function checks need_setup flag, and perfoms nothing unless needed, 1186 * so it's safe to call this multiple times. 1187 * 1188 * This returns zero if unchanged, 1 if the configuration has changed, 1189 * or a negative error code. 1190 */ 1191 int snd_usb_endpoint_configure(struct snd_usb_audio *chip, 1192 struct snd_usb_endpoint *ep) 1193 { 1194 bool iface_first; 1195 int err = 0; 1196 1197 mutex_lock(&chip->mutex); 1198 if (!ep->need_setup) 1199 goto unlock; 1200 1201 /* No need to (re-)configure the sync EP belonging to the same altset */ 1202 if (ep->ep_idx) { 1203 err = snd_usb_endpoint_set_params(chip, ep); 1204 if (err < 0) 1205 goto unlock; 1206 goto done; 1207 } 1208 1209 /* Need to deselect altsetting at first */ 1210 endpoint_set_interface(chip, ep, false); 1211 1212 /* Some UAC1 devices (e.g. Yamaha THR10) need the host interface 1213 * to be set up before parameter setups 1214 */ 1215 iface_first = ep->cur_audiofmt->protocol == UAC_VERSION_1; 1216 if (iface_first) { 1217 err = endpoint_set_interface(chip, ep, true); 1218 if (err < 0) 1219 goto unlock; 1220 } 1221 1222 err = snd_usb_init_pitch(chip, ep->cur_audiofmt); 1223 if (err < 0) 1224 goto unlock; 1225 1226 err = snd_usb_init_sample_rate(chip, ep->cur_audiofmt, ep->cur_rate); 1227 if (err < 0) 1228 goto unlock; 1229 1230 err = snd_usb_endpoint_set_params(chip, ep); 1231 if (err < 0) 1232 goto unlock; 1233 1234 err = snd_usb_select_mode_quirk(chip, ep->cur_audiofmt); 1235 if (err < 0) 1236 goto unlock; 1237 1238 /* for UAC2/3, enable the interface altset here at last */ 1239 if (!iface_first) { 1240 err = endpoint_set_interface(chip, ep, true); 1241 if (err < 0) 1242 goto unlock; 1243 } 1244 1245 done: 1246 ep->need_setup = false; 1247 err = 1; 1248 1249 unlock: 1250 mutex_unlock(&chip->mutex); 1251 return err; 1252 } 1253 1254 /** 1255 * snd_usb_endpoint_start: start an snd_usb_endpoint 1256 * 1257 * @ep: the endpoint to start 1258 * 1259 * A call to this function will increment the running count of the endpoint. 1260 * In case it is not already running, the URBs for this endpoint will be 1261 * submitted. Otherwise, this function does nothing. 1262 * 1263 * Must be balanced to calls of snd_usb_endpoint_stop(). 1264 * 1265 * Returns an error if the URB submission failed, 0 in all other cases. 1266 */ 1267 int snd_usb_endpoint_start(struct snd_usb_endpoint *ep) 1268 { 1269 int err; 1270 unsigned int i; 1271 1272 if (atomic_read(&ep->chip->shutdown)) 1273 return -EBADFD; 1274 1275 if (ep->sync_source) 1276 WRITE_ONCE(ep->sync_source->sync_sink, ep); 1277 1278 usb_audio_dbg(ep->chip, "Starting %s EP 0x%x (running %d)\n", 1279 ep_type_name(ep->type), ep->ep_num, 1280 atomic_read(&ep->running)); 1281 1282 /* already running? */ 1283 if (atomic_inc_return(&ep->running) != 1) 1284 return 0; 1285 1286 ep->active_mask = 0; 1287 ep->unlink_mask = 0; 1288 ep->phase = 0; 1289 ep->sample_accum = 0; 1290 1291 snd_usb_endpoint_start_quirk(ep); 1292 1293 /* 1294 * If this endpoint has a data endpoint as implicit feedback source, 1295 * don't start the urbs here. Instead, mark them all as available, 1296 * wait for the record urbs to return and queue the playback urbs 1297 * from that context. 1298 */ 1299 1300 set_bit(EP_FLAG_RUNNING, &ep->flags); 1301 1302 if (snd_usb_endpoint_implicit_feedback_sink(ep)) { 1303 for (i = 0; i < ep->nurbs; i++) { 1304 struct snd_urb_ctx *ctx = ep->urb + i; 1305 list_add_tail(&ctx->ready_list, &ep->ready_playback_urbs); 1306 } 1307 1308 usb_audio_dbg(ep->chip, "No URB submission due to implicit fb sync\n"); 1309 return 0; 1310 } 1311 1312 for (i = 0; i < ep->nurbs; i++) { 1313 struct urb *urb = ep->urb[i].urb; 1314 1315 if (snd_BUG_ON(!urb)) 1316 goto __error; 1317 1318 if (usb_pipeout(ep->pipe)) { 1319 prepare_outbound_urb(ep, urb->context); 1320 } else { 1321 prepare_inbound_urb(ep, urb->context); 1322 } 1323 1324 err = usb_submit_urb(urb, GFP_ATOMIC); 1325 if (err < 0) { 1326 usb_audio_err(ep->chip, 1327 "cannot submit urb %d, error %d: %s\n", 1328 i, err, usb_error_string(err)); 1329 goto __error; 1330 } 1331 set_bit(i, &ep->active_mask); 1332 } 1333 1334 usb_audio_dbg(ep->chip, "%d URBs submitted for EP 0x%x\n", 1335 ep->nurbs, ep->ep_num); 1336 return 0; 1337 1338 __error: 1339 snd_usb_endpoint_stop(ep); 1340 return -EPIPE; 1341 } 1342 1343 /** 1344 * snd_usb_endpoint_stop: stop an snd_usb_endpoint 1345 * 1346 * @ep: the endpoint to stop (may be NULL) 1347 * 1348 * A call to this function will decrement the running count of the endpoint. 1349 * In case the last user has requested the endpoint stop, the URBs will 1350 * actually be deactivated. 1351 * 1352 * Must be balanced to calls of snd_usb_endpoint_start(). 1353 * 1354 * The caller needs to synchronize the pending stop operation via 1355 * snd_usb_endpoint_sync_pending_stop(). 1356 */ 1357 void snd_usb_endpoint_stop(struct snd_usb_endpoint *ep) 1358 { 1359 if (!ep) 1360 return; 1361 1362 usb_audio_dbg(ep->chip, "Stopping %s EP 0x%x (running %d)\n", 1363 ep_type_name(ep->type), ep->ep_num, 1364 atomic_read(&ep->running)); 1365 1366 if (snd_BUG_ON(!atomic_read(&ep->running))) 1367 return; 1368 1369 if (ep->sync_source) 1370 WRITE_ONCE(ep->sync_source->sync_sink, NULL); 1371 1372 if (!atomic_dec_return(&ep->running)) 1373 stop_and_unlink_urbs(ep, false, false); 1374 } 1375 1376 /** 1377 * snd_usb_endpoint_release: Tear down an snd_usb_endpoint 1378 * 1379 * @ep: the endpoint to release 1380 * 1381 * This function does not care for the endpoint's running count but will tear 1382 * down all the streaming URBs immediately. 1383 */ 1384 void snd_usb_endpoint_release(struct snd_usb_endpoint *ep) 1385 { 1386 release_urbs(ep, 1); 1387 } 1388 1389 /** 1390 * snd_usb_endpoint_free: Free the resources of an snd_usb_endpoint 1391 * 1392 * @ep: the endpoint to free 1393 * 1394 * This free all resources of the given ep. 1395 */ 1396 void snd_usb_endpoint_free(struct snd_usb_endpoint *ep) 1397 { 1398 kfree(ep); 1399 } 1400 1401 /* 1402 * snd_usb_handle_sync_urb: parse an USB sync packet 1403 * 1404 * @ep: the endpoint to handle the packet 1405 * @sender: the sending endpoint 1406 * @urb: the received packet 1407 * 1408 * This function is called from the context of an endpoint that received 1409 * the packet and is used to let another endpoint object handle the payload. 1410 */ 1411 static void snd_usb_handle_sync_urb(struct snd_usb_endpoint *ep, 1412 struct snd_usb_endpoint *sender, 1413 const struct urb *urb) 1414 { 1415 int shift; 1416 unsigned int f; 1417 unsigned long flags; 1418 1419 snd_BUG_ON(ep == sender); 1420 1421 /* 1422 * In case the endpoint is operating in implicit feedback mode, prepare 1423 * a new outbound URB that has the same layout as the received packet 1424 * and add it to the list of pending urbs. queue_pending_output_urbs() 1425 * will take care of them later. 1426 */ 1427 if (snd_usb_endpoint_implicit_feedback_sink(ep) && 1428 atomic_read(&ep->running)) { 1429 1430 /* implicit feedback case */ 1431 int i, bytes = 0; 1432 struct snd_urb_ctx *in_ctx; 1433 struct snd_usb_packet_info *out_packet; 1434 1435 in_ctx = urb->context; 1436 1437 /* Count overall packet size */ 1438 for (i = 0; i < in_ctx->packets; i++) 1439 if (urb->iso_frame_desc[i].status == 0) 1440 bytes += urb->iso_frame_desc[i].actual_length; 1441 1442 /* 1443 * skip empty packets. At least M-Audio's Fast Track Ultra stops 1444 * streaming once it received a 0-byte OUT URB 1445 */ 1446 if (bytes == 0) 1447 return; 1448 1449 spin_lock_irqsave(&ep->lock, flags); 1450 if (ep->next_packet_queued >= ARRAY_SIZE(ep->next_packet)) { 1451 spin_unlock_irqrestore(&ep->lock, flags); 1452 usb_audio_err(ep->chip, 1453 "next package FIFO overflow EP 0x%x\n", 1454 ep->ep_num); 1455 notify_xrun(ep); 1456 return; 1457 } 1458 1459 out_packet = next_packet_fifo_enqueue(ep); 1460 1461 /* 1462 * Iterate through the inbound packet and prepare the lengths 1463 * for the output packet. The OUT packet we are about to send 1464 * will have the same amount of payload bytes per stride as the 1465 * IN packet we just received. Since the actual size is scaled 1466 * by the stride, use the sender stride to calculate the length 1467 * in case the number of channels differ between the implicitly 1468 * fed-back endpoint and the synchronizing endpoint. 1469 */ 1470 1471 out_packet->packets = in_ctx->packets; 1472 for (i = 0; i < in_ctx->packets; i++) { 1473 if (urb->iso_frame_desc[i].status == 0) 1474 out_packet->packet_size[i] = 1475 urb->iso_frame_desc[i].actual_length / sender->stride; 1476 else 1477 out_packet->packet_size[i] = 0; 1478 } 1479 1480 spin_unlock_irqrestore(&ep->lock, flags); 1481 queue_pending_output_urbs(ep); 1482 1483 return; 1484 } 1485 1486 /* 1487 * process after playback sync complete 1488 * 1489 * Full speed devices report feedback values in 10.14 format as samples 1490 * per frame, high speed devices in 16.16 format as samples per 1491 * microframe. 1492 * 1493 * Because the Audio Class 1 spec was written before USB 2.0, many high 1494 * speed devices use a wrong interpretation, some others use an 1495 * entirely different format. 1496 * 1497 * Therefore, we cannot predict what format any particular device uses 1498 * and must detect it automatically. 1499 */ 1500 1501 if (urb->iso_frame_desc[0].status != 0 || 1502 urb->iso_frame_desc[0].actual_length < 3) 1503 return; 1504 1505 f = le32_to_cpup(urb->transfer_buffer); 1506 if (urb->iso_frame_desc[0].actual_length == 3) 1507 f &= 0x00ffffff; 1508 else 1509 f &= 0x0fffffff; 1510 1511 if (f == 0) 1512 return; 1513 1514 if (unlikely(sender->tenor_fb_quirk)) { 1515 /* 1516 * Devices based on Tenor 8802 chipsets (TEAC UD-H01 1517 * and others) sometimes change the feedback value 1518 * by +/- 0x1.0000. 1519 */ 1520 if (f < ep->freqn - 0x8000) 1521 f += 0xf000; 1522 else if (f > ep->freqn + 0x8000) 1523 f -= 0xf000; 1524 } else if (unlikely(ep->freqshift == INT_MIN)) { 1525 /* 1526 * The first time we see a feedback value, determine its format 1527 * by shifting it left or right until it matches the nominal 1528 * frequency value. This assumes that the feedback does not 1529 * differ from the nominal value more than +50% or -25%. 1530 */ 1531 shift = 0; 1532 while (f < ep->freqn - ep->freqn / 4) { 1533 f <<= 1; 1534 shift++; 1535 } 1536 while (f > ep->freqn + ep->freqn / 2) { 1537 f >>= 1; 1538 shift--; 1539 } 1540 ep->freqshift = shift; 1541 } else if (ep->freqshift >= 0) 1542 f <<= ep->freqshift; 1543 else 1544 f >>= -ep->freqshift; 1545 1546 if (likely(f >= ep->freqn - ep->freqn / 8 && f <= ep->freqmax)) { 1547 /* 1548 * If the frequency looks valid, set it. 1549 * This value is referred to in prepare_playback_urb(). 1550 */ 1551 spin_lock_irqsave(&ep->lock, flags); 1552 ep->freqm = f; 1553 spin_unlock_irqrestore(&ep->lock, flags); 1554 } else { 1555 /* 1556 * Out of range; maybe the shift value is wrong. 1557 * Reset it so that we autodetect again the next time. 1558 */ 1559 ep->freqshift = INT_MIN; 1560 } 1561 } 1562 1563