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1 | /* |
2 | * Audio and Music Data Transmission Protocol (IEC 61883-6) streams |
3 | * with Common Isochronous Packet (IEC 61883-1) headers |
4 | * |
5 | * Copyright (c) Clemens Ladisch <clemens@ladisch.de> |
6 | * Licensed under the terms of the GNU General Public License, version 2. |
7 | */ |
8 | |
9 | #include <linux/device.h> |
10 | #include <linux/err.h> |
11 | #include <linux/firewire.h> |
12 | #include <linux/module.h> |
13 | #include <linux/slab.h> |
14 | #include <sound/pcm.h> |
15 | #include "amdtp.h" |
16 | |
17 | #define TICKS_PER_CYCLE 3072 |
18 | #define CYCLES_PER_SECOND 8000 |
19 | #define TICKS_PER_SECOND (TICKS_PER_CYCLE * CYCLES_PER_SECOND) |
20 | |
21 | #define TRANSFER_DELAY_TICKS 0x2e00 /* 479.17 µs */ |
22 | |
23 | #define TAG_CIP 1 |
24 | |
25 | #define CIP_EOH (1u << 31) |
26 | #define CIP_FMT_AM (0x10 << 24) |
27 | #define AMDTP_FDF_AM824 (0 << 19) |
28 | #define AMDTP_FDF_SFC_SHIFT 16 |
29 | |
30 | /* TODO: make these configurable */ |
31 | #define INTERRUPT_INTERVAL 16 |
32 | #define QUEUE_LENGTH 48 |
33 | |
34 | static void pcm_period_tasklet(unsigned long data); |
35 | |
36 | /** |
37 | * amdtp_out_stream_init - initialize an AMDTP output stream structure |
38 | * @s: the AMDTP output stream to initialize |
39 | * @unit: the target of the stream |
40 | * @flags: the packet transmission method to use |
41 | */ |
42 | int amdtp_out_stream_init(struct amdtp_out_stream *s, struct fw_unit *unit, |
43 | enum cip_out_flags flags) |
44 | { |
45 | if (flags != CIP_NONBLOCKING) |
46 | return -EINVAL; |
47 | |
48 | s->unit = fw_unit_get(unit); |
49 | s->flags = flags; |
50 | s->context = ERR_PTR(-1); |
51 | mutex_init(&s->mutex); |
52 | tasklet_init(&s->period_tasklet, pcm_period_tasklet, (unsigned long)s); |
53 | s->packet_index = 0; |
54 | |
55 | return 0; |
56 | } |
57 | EXPORT_SYMBOL(amdtp_out_stream_init); |
58 | |
59 | /** |
60 | * amdtp_out_stream_destroy - free stream resources |
61 | * @s: the AMDTP output stream to destroy |
62 | */ |
63 | void amdtp_out_stream_destroy(struct amdtp_out_stream *s) |
64 | { |
65 | WARN_ON(!IS_ERR(s->context)); |
66 | mutex_destroy(&s->mutex); |
67 | fw_unit_put(s->unit); |
68 | } |
69 | EXPORT_SYMBOL(amdtp_out_stream_destroy); |
70 | |
71 | /** |
72 | * amdtp_out_stream_set_rate - set the sample rate |
73 | * @s: the AMDTP output stream to configure |
74 | * @rate: the sample rate |
75 | * |
76 | * The sample rate must be set before the stream is started, and must not be |
77 | * changed while the stream is running. |
78 | */ |
79 | void amdtp_out_stream_set_rate(struct amdtp_out_stream *s, unsigned int rate) |
80 | { |
81 | static const struct { |
82 | unsigned int rate; |
83 | unsigned int syt_interval; |
84 | } rate_info[] = { |
85 | [CIP_SFC_32000] = { 32000, 8, }, |
86 | [CIP_SFC_44100] = { 44100, 8, }, |
87 | [CIP_SFC_48000] = { 48000, 8, }, |
88 | [CIP_SFC_88200] = { 88200, 16, }, |
89 | [CIP_SFC_96000] = { 96000, 16, }, |
90 | [CIP_SFC_176400] = { 176400, 32, }, |
91 | [CIP_SFC_192000] = { 192000, 32, }, |
92 | }; |
93 | unsigned int sfc; |
94 | |
95 | if (WARN_ON(!IS_ERR(s->context))) |
96 | return; |
97 | |
98 | for (sfc = 0; sfc < ARRAY_SIZE(rate_info); ++sfc) |
99 | if (rate_info[sfc].rate == rate) { |
100 | s->sfc = sfc; |
101 | s->syt_interval = rate_info[sfc].syt_interval; |
102 | return; |
103 | } |
104 | WARN_ON(1); |
105 | } |
106 | EXPORT_SYMBOL(amdtp_out_stream_set_rate); |
107 | |
108 | /** |
109 | * amdtp_out_stream_get_max_payload - get the stream's packet size |
110 | * @s: the AMDTP output stream |
111 | * |
112 | * This function must not be called before the stream has been configured |
113 | * with amdtp_out_stream_set_hw_params(), amdtp_out_stream_set_pcm(), and |
114 | * amdtp_out_stream_set_midi(). |
115 | */ |
116 | unsigned int amdtp_out_stream_get_max_payload(struct amdtp_out_stream *s) |
117 | { |
118 | static const unsigned int max_data_blocks[] = { |
119 | [CIP_SFC_32000] = 4, |
120 | [CIP_SFC_44100] = 6, |
121 | [CIP_SFC_48000] = 6, |
122 | [CIP_SFC_88200] = 12, |
123 | [CIP_SFC_96000] = 12, |
124 | [CIP_SFC_176400] = 23, |
125 | [CIP_SFC_192000] = 24, |
126 | }; |
127 | |
128 | s->data_block_quadlets = s->pcm_channels; |
129 | s->data_block_quadlets += DIV_ROUND_UP(s->midi_ports, 8); |
130 | |
131 | return 8 + max_data_blocks[s->sfc] * 4 * s->data_block_quadlets; |
132 | } |
133 | EXPORT_SYMBOL(amdtp_out_stream_get_max_payload); |
134 | |
135 | static void amdtp_write_s16(struct amdtp_out_stream *s, |
136 | struct snd_pcm_substream *pcm, |
137 | __be32 *buffer, unsigned int frames); |
138 | static void amdtp_write_s32(struct amdtp_out_stream *s, |
139 | struct snd_pcm_substream *pcm, |
140 | __be32 *buffer, unsigned int frames); |
141 | |
142 | /** |
143 | * amdtp_out_stream_set_pcm_format - set the PCM format |
144 | * @s: the AMDTP output stream to configure |
145 | * @format: the format of the ALSA PCM device |
146 | * |
147 | * The sample format must be set before the stream is started, and must not be |
148 | * changed while the stream is running. |
149 | */ |
150 | void amdtp_out_stream_set_pcm_format(struct amdtp_out_stream *s, |
151 | snd_pcm_format_t format) |
152 | { |
153 | if (WARN_ON(!IS_ERR(s->context))) |
154 | return; |
155 | |
156 | switch (format) { |
157 | default: |
158 | WARN_ON(1); |
159 | /* fall through */ |
160 | case SNDRV_PCM_FORMAT_S16: |
161 | s->transfer_samples = amdtp_write_s16; |
162 | break; |
163 | case SNDRV_PCM_FORMAT_S32: |
164 | s->transfer_samples = amdtp_write_s32; |
165 | break; |
166 | } |
167 | } |
168 | EXPORT_SYMBOL(amdtp_out_stream_set_pcm_format); |
169 | |
170 | /** |
171 | * amdtp_out_stream_pcm_prepare - prepare PCM device for running |
172 | * @s: the AMDTP output stream |
173 | * |
174 | * This function should be called from the PCM device's .prepare callback. |
175 | */ |
176 | void amdtp_out_stream_pcm_prepare(struct amdtp_out_stream *s) |
177 | { |
178 | tasklet_kill(&s->period_tasklet); |
179 | s->pcm_buffer_pointer = 0; |
180 | s->pcm_period_pointer = 0; |
181 | s->pointer_flush = true; |
182 | } |
183 | EXPORT_SYMBOL(amdtp_out_stream_pcm_prepare); |
184 | |
185 | static unsigned int calculate_data_blocks(struct amdtp_out_stream *s) |
186 | { |
187 | unsigned int phase, data_blocks; |
188 | |
189 | if (!cip_sfc_is_base_44100(s->sfc)) { |
190 | /* Sample_rate / 8000 is an integer, and precomputed. */ |
191 | data_blocks = s->data_block_state; |
192 | } else { |
193 | phase = s->data_block_state; |
194 | |
195 | /* |
196 | * This calculates the number of data blocks per packet so that |
197 | * 1) the overall rate is correct and exactly synchronized to |
198 | * the bus clock, and |
199 | * 2) packets with a rounded-up number of blocks occur as early |
200 | * as possible in the sequence (to prevent underruns of the |
201 | * device's buffer). |
202 | */ |
203 | if (s->sfc == CIP_SFC_44100) |
204 | /* 6 6 5 6 5 6 5 ... */ |
205 | data_blocks = 5 + ((phase & 1) ^ |
206 | (phase == 0 || phase >= 40)); |
207 | else |
208 | /* 12 11 11 11 11 ... or 23 22 22 22 22 ... */ |
209 | data_blocks = 11 * (s->sfc >> 1) + (phase == 0); |
210 | if (++phase >= (80 >> (s->sfc >> 1))) |
211 | phase = 0; |
212 | s->data_block_state = phase; |
213 | } |
214 | |
215 | return data_blocks; |
216 | } |
217 | |
218 | static unsigned int calculate_syt(struct amdtp_out_stream *s, |
219 | unsigned int cycle) |
220 | { |
221 | unsigned int syt_offset, phase, index, syt; |
222 | |
223 | if (s->last_syt_offset < TICKS_PER_CYCLE) { |
224 | if (!cip_sfc_is_base_44100(s->sfc)) |
225 | syt_offset = s->last_syt_offset + s->syt_offset_state; |
226 | else { |
227 | /* |
228 | * The time, in ticks, of the n'th SYT_INTERVAL sample is: |
229 | * n * SYT_INTERVAL * 24576000 / sample_rate |
230 | * Modulo TICKS_PER_CYCLE, the difference between successive |
231 | * elements is about 1386.23. Rounding the results of this |
232 | * formula to the SYT precision results in a sequence of |
233 | * differences that begins with: |
234 | * 1386 1386 1387 1386 1386 1386 1387 1386 1386 1386 1387 ... |
235 | * This code generates _exactly_ the same sequence. |
236 | */ |
237 | phase = s->syt_offset_state; |
238 | index = phase % 13; |
239 | syt_offset = s->last_syt_offset; |
240 | syt_offset += 1386 + ((index && !(index & 3)) || |
241 | phase == 146); |
242 | if (++phase >= 147) |
243 | phase = 0; |
244 | s->syt_offset_state = phase; |
245 | } |
246 | } else |
247 | syt_offset = s->last_syt_offset - TICKS_PER_CYCLE; |
248 | s->last_syt_offset = syt_offset; |
249 | |
250 | if (syt_offset < TICKS_PER_CYCLE) { |
251 | syt_offset += TRANSFER_DELAY_TICKS - TICKS_PER_CYCLE; |
252 | syt = (cycle + syt_offset / TICKS_PER_CYCLE) << 12; |
253 | syt += syt_offset % TICKS_PER_CYCLE; |
254 | |
255 | return syt & 0xffff; |
256 | } else { |
257 | return 0xffff; /* no info */ |
258 | } |
259 | } |
260 | |
261 | static void amdtp_write_s32(struct amdtp_out_stream *s, |
262 | struct snd_pcm_substream *pcm, |
263 | __be32 *buffer, unsigned int frames) |
264 | { |
265 | struct snd_pcm_runtime *runtime = pcm->runtime; |
266 | unsigned int channels, remaining_frames, frame_step, i, c; |
267 | const u32 *src; |
268 | |
269 | channels = s->pcm_channels; |
270 | src = (void *)runtime->dma_area + |
271 | s->pcm_buffer_pointer * (runtime->frame_bits / 8); |
272 | remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer; |
273 | frame_step = s->data_block_quadlets - channels; |
274 | |
275 | for (i = 0; i < frames; ++i) { |
276 | for (c = 0; c < channels; ++c) { |
277 | *buffer = cpu_to_be32((*src >> 8) | 0x40000000); |
278 | src++; |
279 | buffer++; |
280 | } |
281 | buffer += frame_step; |
282 | if (--remaining_frames == 0) |
283 | src = (void *)runtime->dma_area; |
284 | } |
285 | } |
286 | |
287 | static void amdtp_write_s16(struct amdtp_out_stream *s, |
288 | struct snd_pcm_substream *pcm, |
289 | __be32 *buffer, unsigned int frames) |
290 | { |
291 | struct snd_pcm_runtime *runtime = pcm->runtime; |
292 | unsigned int channels, remaining_frames, frame_step, i, c; |
293 | const u16 *src; |
294 | |
295 | channels = s->pcm_channels; |
296 | src = (void *)runtime->dma_area + |
297 | s->pcm_buffer_pointer * (runtime->frame_bits / 8); |
298 | remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer; |
299 | frame_step = s->data_block_quadlets - channels; |
300 | |
301 | for (i = 0; i < frames; ++i) { |
302 | for (c = 0; c < channels; ++c) { |
303 | *buffer = cpu_to_be32((*src << 8) | 0x40000000); |
304 | src++; |
305 | buffer++; |
306 | } |
307 | buffer += frame_step; |
308 | if (--remaining_frames == 0) |
309 | src = (void *)runtime->dma_area; |
310 | } |
311 | } |
312 | |
313 | static void amdtp_fill_pcm_silence(struct amdtp_out_stream *s, |
314 | __be32 *buffer, unsigned int frames) |
315 | { |
316 | unsigned int i, c; |
317 | |
318 | for (i = 0; i < frames; ++i) { |
319 | for (c = 0; c < s->pcm_channels; ++c) |
320 | buffer[c] = cpu_to_be32(0x40000000); |
321 | buffer += s->data_block_quadlets; |
322 | } |
323 | } |
324 | |
325 | static void amdtp_fill_midi(struct amdtp_out_stream *s, |
326 | __be32 *buffer, unsigned int frames) |
327 | { |
328 | unsigned int i; |
329 | |
330 | for (i = 0; i < frames; ++i) |
331 | buffer[s->pcm_channels + i * s->data_block_quadlets] = |
332 | cpu_to_be32(0x80000000); |
333 | } |
334 | |
335 | static void queue_out_packet(struct amdtp_out_stream *s, unsigned int cycle) |
336 | { |
337 | __be32 *buffer; |
338 | unsigned int index, data_blocks, syt, ptr; |
339 | struct snd_pcm_substream *pcm; |
340 | struct fw_iso_packet packet; |
341 | int err; |
342 | |
343 | if (s->packet_index < 0) |
344 | return; |
345 | index = s->packet_index; |
346 | |
347 | data_blocks = calculate_data_blocks(s); |
348 | syt = calculate_syt(s, cycle); |
349 | |
350 | buffer = s->buffer.packets[index].buffer; |
351 | buffer[0] = cpu_to_be32(ACCESS_ONCE(s->source_node_id_field) | |
352 | (s->data_block_quadlets << 16) | |
353 | s->data_block_counter); |
354 | buffer[1] = cpu_to_be32(CIP_EOH | CIP_FMT_AM | AMDTP_FDF_AM824 | |
355 | (s->sfc << AMDTP_FDF_SFC_SHIFT) | syt); |
356 | buffer += 2; |
357 | |
358 | pcm = ACCESS_ONCE(s->pcm); |
359 | if (pcm) |
360 | s->transfer_samples(s, pcm, buffer, data_blocks); |
361 | else |
362 | amdtp_fill_pcm_silence(s, buffer, data_blocks); |
363 | if (s->midi_ports) |
364 | amdtp_fill_midi(s, buffer, data_blocks); |
365 | |
366 | s->data_block_counter = (s->data_block_counter + data_blocks) & 0xff; |
367 | |
368 | packet.payload_length = 8 + data_blocks * 4 * s->data_block_quadlets; |
369 | packet.interrupt = IS_ALIGNED(index + 1, INTERRUPT_INTERVAL); |
370 | packet.skip = 0; |
371 | packet.tag = TAG_CIP; |
372 | packet.sy = 0; |
373 | packet.header_length = 0; |
374 | |
375 | err = fw_iso_context_queue(s->context, &packet, &s->buffer.iso_buffer, |
376 | s->buffer.packets[index].offset); |
377 | if (err < 0) { |
378 | dev_err(&s->unit->device, "queueing error: %d\n", err); |
379 | s->packet_index = -1; |
380 | amdtp_out_stream_pcm_abort(s); |
381 | return; |
382 | } |
383 | |
384 | if (++index >= QUEUE_LENGTH) |
385 | index = 0; |
386 | s->packet_index = index; |
387 | |
388 | if (pcm) { |
389 | ptr = s->pcm_buffer_pointer + data_blocks; |
390 | if (ptr >= pcm->runtime->buffer_size) |
391 | ptr -= pcm->runtime->buffer_size; |
392 | ACCESS_ONCE(s->pcm_buffer_pointer) = ptr; |
393 | |
394 | s->pcm_period_pointer += data_blocks; |
395 | if (s->pcm_period_pointer >= pcm->runtime->period_size) { |
396 | s->pcm_period_pointer -= pcm->runtime->period_size; |
397 | s->pointer_flush = false; |
398 | tasklet_hi_schedule(&s->period_tasklet); |
399 | } |
400 | } |
401 | } |
402 | |
403 | static void pcm_period_tasklet(unsigned long data) |
404 | { |
405 | struct amdtp_out_stream *s = (void *)data; |
406 | struct snd_pcm_substream *pcm = ACCESS_ONCE(s->pcm); |
407 | |
408 | if (pcm) |
409 | snd_pcm_period_elapsed(pcm); |
410 | } |
411 | |
412 | static void out_packet_callback(struct fw_iso_context *context, u32 cycle, |
413 | size_t header_length, void *header, void *data) |
414 | { |
415 | struct amdtp_out_stream *s = data; |
416 | unsigned int i, packets = header_length / 4; |
417 | |
418 | /* |
419 | * Compute the cycle of the last queued packet. |
420 | * (We need only the four lowest bits for the SYT, so we can ignore |
421 | * that bits 0-11 must wrap around at 3072.) |
422 | */ |
423 | cycle += QUEUE_LENGTH - packets; |
424 | |
425 | for (i = 0; i < packets; ++i) |
426 | queue_out_packet(s, ++cycle); |
427 | fw_iso_context_queue_flush(s->context); |
428 | } |
429 | |
430 | static int queue_initial_skip_packets(struct amdtp_out_stream *s) |
431 | { |
432 | struct fw_iso_packet skip_packet = { |
433 | .skip = 1, |
434 | }; |
435 | unsigned int i; |
436 | int err; |
437 | |
438 | for (i = 0; i < QUEUE_LENGTH; ++i) { |
439 | skip_packet.interrupt = IS_ALIGNED(s->packet_index + 1, |
440 | INTERRUPT_INTERVAL); |
441 | err = fw_iso_context_queue(s->context, &skip_packet, NULL, 0); |
442 | if (err < 0) |
443 | return err; |
444 | if (++s->packet_index >= QUEUE_LENGTH) |
445 | s->packet_index = 0; |
446 | } |
447 | |
448 | return 0; |
449 | } |
450 | |
451 | /** |
452 | * amdtp_out_stream_start - start sending packets |
453 | * @s: the AMDTP output stream to start |
454 | * @channel: the isochronous channel on the bus |
455 | * @speed: firewire speed code |
456 | * |
457 | * The stream cannot be started until it has been configured with |
458 | * amdtp_out_stream_set_hw_params(), amdtp_out_stream_set_pcm(), and |
459 | * amdtp_out_stream_set_midi(); and it must be started before any |
460 | * PCM or MIDI device can be started. |
461 | */ |
462 | int amdtp_out_stream_start(struct amdtp_out_stream *s, int channel, int speed) |
463 | { |
464 | static const struct { |
465 | unsigned int data_block; |
466 | unsigned int syt_offset; |
467 | } initial_state[] = { |
468 | [CIP_SFC_32000] = { 4, 3072 }, |
469 | [CIP_SFC_48000] = { 6, 1024 }, |
470 | [CIP_SFC_96000] = { 12, 1024 }, |
471 | [CIP_SFC_192000] = { 24, 1024 }, |
472 | [CIP_SFC_44100] = { 0, 67 }, |
473 | [CIP_SFC_88200] = { 0, 67 }, |
474 | [CIP_SFC_176400] = { 0, 67 }, |
475 | }; |
476 | int err; |
477 | |
478 | mutex_lock(&s->mutex); |
479 | |
480 | if (WARN_ON(!IS_ERR(s->context) || |
481 | (!s->pcm_channels && !s->midi_ports))) { |
482 | err = -EBADFD; |
483 | goto err_unlock; |
484 | } |
485 | |
486 | s->data_block_state = initial_state[s->sfc].data_block; |
487 | s->syt_offset_state = initial_state[s->sfc].syt_offset; |
488 | s->last_syt_offset = TICKS_PER_CYCLE; |
489 | |
490 | err = iso_packets_buffer_init(&s->buffer, s->unit, QUEUE_LENGTH, |
491 | amdtp_out_stream_get_max_payload(s), |
492 | DMA_TO_DEVICE); |
493 | if (err < 0) |
494 | goto err_unlock; |
495 | |
496 | s->context = fw_iso_context_create(fw_parent_device(s->unit)->card, |
497 | FW_ISO_CONTEXT_TRANSMIT, |
498 | channel, speed, 0, |
499 | out_packet_callback, s); |
500 | if (IS_ERR(s->context)) { |
501 | err = PTR_ERR(s->context); |
502 | if (err == -EBUSY) |
503 | dev_err(&s->unit->device, |
504 | "no free output stream on this controller\n"); |
505 | goto err_buffer; |
506 | } |
507 | |
508 | amdtp_out_stream_update(s); |
509 | |
510 | s->packet_index = 0; |
511 | s->data_block_counter = 0; |
512 | err = queue_initial_skip_packets(s); |
513 | if (err < 0) |
514 | goto err_context; |
515 | |
516 | err = fw_iso_context_start(s->context, -1, 0, 0); |
517 | if (err < 0) |
518 | goto err_context; |
519 | |
520 | mutex_unlock(&s->mutex); |
521 | |
522 | return 0; |
523 | |
524 | err_context: |
525 | fw_iso_context_destroy(s->context); |
526 | s->context = ERR_PTR(-1); |
527 | err_buffer: |
528 | iso_packets_buffer_destroy(&s->buffer, s->unit); |
529 | err_unlock: |
530 | mutex_unlock(&s->mutex); |
531 | |
532 | return err; |
533 | } |
534 | EXPORT_SYMBOL(amdtp_out_stream_start); |
535 | |
536 | /** |
537 | * amdtp_out_stream_pcm_pointer - get the PCM buffer position |
538 | * @s: the AMDTP output stream that transports the PCM data |
539 | * |
540 | * Returns the current buffer position, in frames. |
541 | */ |
542 | unsigned long amdtp_out_stream_pcm_pointer(struct amdtp_out_stream *s) |
543 | { |
544 | /* this optimization is allowed to be racy */ |
545 | if (s->pointer_flush) |
546 | fw_iso_context_flush_completions(s->context); |
547 | else |
548 | s->pointer_flush = true; |
549 | |
550 | return ACCESS_ONCE(s->pcm_buffer_pointer); |
551 | } |
552 | EXPORT_SYMBOL(amdtp_out_stream_pcm_pointer); |
553 | |
554 | /** |
555 | * amdtp_out_stream_update - update the stream after a bus reset |
556 | * @s: the AMDTP output stream |
557 | */ |
558 | void amdtp_out_stream_update(struct amdtp_out_stream *s) |
559 | { |
560 | ACCESS_ONCE(s->source_node_id_field) = |
561 | (fw_parent_device(s->unit)->card->node_id & 0x3f) << 24; |
562 | } |
563 | EXPORT_SYMBOL(amdtp_out_stream_update); |
564 | |
565 | /** |
566 | * amdtp_out_stream_stop - stop sending packets |
567 | * @s: the AMDTP output stream to stop |
568 | * |
569 | * All PCM and MIDI devices of the stream must be stopped before the stream |
570 | * itself can be stopped. |
571 | */ |
572 | void amdtp_out_stream_stop(struct amdtp_out_stream *s) |
573 | { |
574 | mutex_lock(&s->mutex); |
575 | |
576 | if (IS_ERR(s->context)) { |
577 | mutex_unlock(&s->mutex); |
578 | return; |
579 | } |
580 | |
581 | tasklet_kill(&s->period_tasklet); |
582 | fw_iso_context_stop(s->context); |
583 | fw_iso_context_destroy(s->context); |
584 | s->context = ERR_PTR(-1); |
585 | iso_packets_buffer_destroy(&s->buffer, s->unit); |
586 | |
587 | mutex_unlock(&s->mutex); |
588 | } |
589 | EXPORT_SYMBOL(amdtp_out_stream_stop); |
590 | |
591 | /** |
592 | * amdtp_out_stream_pcm_abort - abort the running PCM device |
593 | * @s: the AMDTP stream about to be stopped |
594 | * |
595 | * If the isochronous stream needs to be stopped asynchronously, call this |
596 | * function first to stop the PCM device. |
597 | */ |
598 | void amdtp_out_stream_pcm_abort(struct amdtp_out_stream *s) |
599 | { |
600 | struct snd_pcm_substream *pcm; |
601 | |
602 | pcm = ACCESS_ONCE(s->pcm); |
603 | if (pcm) { |
604 | snd_pcm_stream_lock_irq(pcm); |
605 | if (snd_pcm_running(pcm)) |
606 | snd_pcm_stop(pcm, SNDRV_PCM_STATE_XRUN); |
607 | snd_pcm_stream_unlock_irq(pcm); |
608 | } |
609 | } |
610 | EXPORT_SYMBOL(amdtp_out_stream_pcm_abort); |
611 |
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javiroman/ks7010
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Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
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v3.9