diff --git a/include/sound/pcm.h b/include/sound/pcm.h index dbce137d8806..ac8f3aef9205 100644 --- a/include/sound/pcm.h +++ b/include/sound/pcm.h @@ -402,7 +402,7 @@ struct snd_pcm_runtime { snd_pcm_uframes_t silence_start; /* starting pointer to silence area */ snd_pcm_uframes_t silence_filled; /* already filled part of silence area */ - unsigned char sync[16]; /* hardware synchronization ID */ + bool std_sync_id; /* hardware synchronization - standard per card ID */ /* -- mmap -- */ struct snd_pcm_mmap_status *status; @@ -1156,7 +1156,18 @@ int snd_pcm_format_set_silence(snd_pcm_format_t format, void *buf, unsigned int void snd_pcm_set_ops(struct snd_pcm * pcm, int direction, const struct snd_pcm_ops *ops); -void snd_pcm_set_sync(struct snd_pcm_substream *substream); +void snd_pcm_set_sync_per_card(struct snd_pcm_substream *substream, struct snd_pcm_hw_params *params, + const unsigned char *id, unsigned int len); +/** + * snd_pcm_set_sync - set the PCM sync id + * @substream: the pcm substream + * + * Use the default PCM sync identifier for the specific card. + */ +static inline void snd_pcm_set_sync(struct snd_pcm_substream *substream) +{ + substream->runtime->std_sync_id = true; +} int snd_pcm_lib_ioctl(struct snd_pcm_substream *substream, unsigned int cmd, void *arg); void snd_pcm_period_elapsed_under_stream_lock(struct snd_pcm_substream *substream); diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c index f64a03f79b01..e48a84f8e977 100644 --- a/sound/core/pcm_lib.c +++ b/sound/core/pcm_lib.c @@ -516,19 +516,37 @@ void snd_pcm_set_ops(struct snd_pcm *pcm, int direction, EXPORT_SYMBOL(snd_pcm_set_ops); /** - * snd_pcm_set_sync - set the PCM sync id + * snd_pcm_set_sync_per_card - set the PCM sync id with card number * @substream: the pcm substream + * @params: modified hardware parameters + * @id: identifier (max 12 bytes) + * @len: identifier length (max 12 bytes) * - * Sets the PCM sync identifier for the card. + * Sets the PCM sync identifier for the card with zero padding. + * + * User space or any user should use this 16-byte identifier for a comparison only + * to check if two IDs are similar or different. Special case is the identifier + * containing only zeros. Interpretation for this combination is - empty (not set). + * The contents of the identifier should not be interpreted in any other way. + * + * The synchronization ID must be unique per clock source (usually one sound card, + * but multiple soundcard may use one PCM word clock source which means that they + * are fully synchronized). + * + * This routine composes this ID using card number in first four bytes and + * 12-byte additional ID. When other ID composition is used (e.g. for multiple + * sound cards), make sure that the composition does not clash with this + * composition scheme. */ -void snd_pcm_set_sync(struct snd_pcm_substream *substream) +void snd_pcm_set_sync_per_card(struct snd_pcm_substream *substream, + struct snd_pcm_hw_params *params, + const unsigned char *id, unsigned int len) { - struct snd_pcm_runtime *runtime = substream->runtime; - - *(__u32 *)runtime->sync = cpu_to_le32(substream->pcm->card->number); - memset(runtime->sync + 4, 0xff, sizeof(runtime->sync) - 4); + *(__u32 *)params->sync = cpu_to_le32(substream->pcm->card->number); + len = max(12, len); + strncpy(params->sync + 4, id, len); + memset(params->sync + 4 + len, 0, 12 - len); } -EXPORT_SYMBOL(snd_pcm_set_sync); /* * Standard ioctl routine @@ -1808,22 +1826,15 @@ static int snd_pcm_lib_ioctl_fifo_size(struct snd_pcm_substream *substream, return 0; } -/** - * is sync id (clock id) empty? - */ -static inline bool pcm_sync_empty(const unsigned char *sync) -{ - return sync[0] == 0 && sync[1] == 0 && sync[2] == 0 && sync[3] == 0 && - sync[4] == 0 && sync[5] == 0 && sync[6] == 0 && sync[7] == 0; -} - static int snd_pcm_lib_ioctl_sync_id(struct snd_pcm_substream *substream, void *arg) { - struct snd_pcm_hw_params *params = arg; + static const unsigned char id[12] = { 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff }; - if (pcm_sync_empty(params->sync)) - memcpy(params->sync, substream->runtime->sync, sizeof(params->sync)); + if (substream->runtime->std_sync_id) + snd_pcm_set_sync_per_card(substream, arg, id, sizeof(id)); return 0; } diff --git a/sound/pci/emu10k1/p16v.c b/sound/pci/emu10k1/p16v.c index 773725dbdfbd..a9a75891f1da 100644 --- a/sound/pci/emu10k1/p16v.c +++ b/sound/pci/emu10k1/p16v.c @@ -174,10 +174,6 @@ static int snd_p16v_pcm_open_playback_channel(struct snd_pcm_substream *substrea if (err < 0) return err; - *(__u32 *)runtime->sync = cpu_to_le32(substream->pcm->card->number); - memset(runtime->sync + 4, 0, sizeof(runtime->sync) - 4); - strncpy(runtime->sync + 4, "P16V", 4); - return 0; } @@ -225,6 +221,17 @@ static int snd_p16v_pcm_open_capture(struct snd_pcm_substream *substream) return snd_p16v_pcm_open_capture_channel(substream, 0); } +static int snd_p16v_pcm_ioctl_playback(struct snd_pcm_substream *substream, + unsigned int cmd, void *arg) +{ + if (cmd == SNDRV_PCM_IOCTL1_SYNC_ID) { + static const unsigned char id[4] = { 'P', '1', '6', 'V' }; + snd_pcm_set_sync_per_card(substream, arg, id, 4); + return 0; + } + return snd_pcm_lib_ioctl(substream, cmd, arg); +} + /* prepare playback callback */ static int snd_p16v_pcm_prepare_playback(struct snd_pcm_substream *substream) { @@ -530,6 +537,7 @@ snd_p16v_pcm_pointer_capture(struct snd_pcm_substream *substream) static const struct snd_pcm_ops snd_p16v_playback_front_ops = { .open = snd_p16v_pcm_open_playback_front, .close = snd_p16v_pcm_close_playback, + .ioctl = snd_p16v_pcm_ioctl_playback, .prepare = snd_p16v_pcm_prepare_playback, .trigger = snd_p16v_pcm_trigger_playback, .pointer = snd_p16v_pcm_pointer_playback,