diff options
Diffstat (limited to 'sound/drivers/aloop.c')
| -rw-r--r-- | sound/drivers/aloop.c | 477 |
1 files changed, 476 insertions, 1 deletions
diff --git a/sound/drivers/aloop.c b/sound/drivers/aloop.c index 0eacaa9d7862..e8a85f887222 100644 --- a/sound/drivers/aloop.c +++ b/sound/drivers/aloop.c @@ -28,6 +28,7 @@ #include <sound/pcm_params.h> #include <sound/info.h> #include <sound/initval.h> +#include <sound/timer.h> MODULE_AUTHOR("Jaroslav Kysela <perex@perex.cz>"); MODULE_DESCRIPTION("A loopback soundcard"); @@ -41,6 +42,7 @@ static char *id[SNDRV_CARDS] = SNDRV_DEFAULT_STR; /* ID for this card */ static bool enable[SNDRV_CARDS] = {1, [1 ... (SNDRV_CARDS - 1)] = 0}; static int pcm_substreams[SNDRV_CARDS] = {[0 ... (SNDRV_CARDS - 1)] = 8}; static int pcm_notify[SNDRV_CARDS]; +static char *timer_source[SNDRV_CARDS]; module_param_array(index, int, NULL, 0444); MODULE_PARM_DESC(index, "Index value for loopback soundcard."); @@ -52,6 +54,8 @@ module_param_array(pcm_substreams, int, NULL, 0444); MODULE_PARM_DESC(pcm_substreams, "PCM substreams # (1-8) for loopback driver."); module_param_array(pcm_notify, int, NULL, 0444); MODULE_PARM_DESC(pcm_notify, "Break capture when PCM format/rate/channels changes."); +module_param_array(timer_source, charp, NULL, 0444); +MODULE_PARM_DESC(timer_source, "Sound card name or number and device/subdevice number of timer to be used. Empty string for jiffies timer [default]."); #define NO_PITCH 100000 @@ -102,6 +106,13 @@ struct loopback_cable { unsigned int pause; /* timer specific */ struct loopback_ops *ops; + /* If sound timer is used */ + struct { + int stream; + struct snd_timer_id id; + struct tasklet_struct event_tasklet; + struct snd_timer_instance *instance; + } snd_timer; }; struct loopback_setup { @@ -122,6 +133,7 @@ struct loopback { struct loopback_cable *cables[MAX_PCM_SUBSTREAMS][2]; struct snd_pcm *pcm[2]; struct loopback_setup setup[MAX_PCM_SUBSTREAMS][2]; + const char *timer_source; }; struct loopback_pcm { @@ -145,6 +157,7 @@ struct loopback_pcm { unsigned int period_size_frac; /* period size in jiffies ticks */ unsigned int last_drift; unsigned long last_jiffies; + /* If jiffies timer is used */ struct timer_list timer; }; @@ -213,6 +226,35 @@ static int loopback_jiffies_timer_start(struct loopback_pcm *dpcm) } /* call in cable->lock */ +static int loopback_snd_timer_start(struct loopback_pcm *dpcm) +{ + struct loopback_cable *cable = dpcm->cable; + int err; + + /* Loopback device has to use same period as timer card. Therefore + * wake up for each snd_pcm_period_elapsed() call of timer card. + */ + err = snd_timer_start(cable->snd_timer.instance, 1); + if (err < 0) { + /* do not report error if trying to start but already + * running. For example called by opposite substream + * of the same cable + */ + if (err == -EBUSY) + return 0; + + pcm_err(dpcm->substream->pcm, + "snd_timer_start(%d,%d,%d) failed with %d", + cable->snd_timer.id.card, + cable->snd_timer.id.device, + cable->snd_timer.id.subdevice, + err); + } + + return err; +} + +/* call in cable->lock */ static inline int loopback_jiffies_timer_stop(struct loopback_pcm *dpcm) { del_timer(&dpcm->timer); @@ -221,6 +263,29 @@ static inline int loopback_jiffies_timer_stop(struct loopback_pcm *dpcm) return 0; } +/* call in cable->lock */ +static int loopback_snd_timer_stop(struct loopback_pcm *dpcm) +{ + struct loopback_cable *cable = dpcm->cable; + int err; + + /* only stop if both devices (playback and capture) are not running */ + if (cable->running ^ cable->pause) + return 0; + + err = snd_timer_stop(cable->snd_timer.instance); + if (err < 0) { + pcm_err(dpcm->substream->pcm, + "snd_timer_stop(%d,%d,%d) failed with %d", + cable->snd_timer.id.card, + cable->snd_timer.id.device, + cable->snd_timer.id.subdevice, + err); + } + + return err; +} + static inline int loopback_jiffies_timer_stop_sync(struct loopback_pcm *dpcm) { del_timer_sync(&dpcm->timer); @@ -228,6 +293,30 @@ static inline int loopback_jiffies_timer_stop_sync(struct loopback_pcm *dpcm) return 0; } +/* call in loopback->cable_lock */ +static int loopback_snd_timer_close_cable(struct loopback_pcm *dpcm) +{ + struct loopback_cable *cable = dpcm->cable; + + /* snd_timer was not opened */ + if (!cable->snd_timer.instance) + return 0; + + /* wait till drain tasklet has finished if requested */ + tasklet_kill(&cable->snd_timer.event_tasklet); + + /* will only be called from free_cable() when other stream was + * already closed. Other stream cannot be reopened as long as + * loopback->cable_lock is locked. Therefore no need to lock + * cable->lock; + */ + snd_timer_close(cable->snd_timer.instance); + snd_timer_instance_free(cable->snd_timer.instance); + memset(&cable->snd_timer, 0, sizeof(cable->snd_timer)); + + return 0; +} + static int loopback_check_format(struct loopback_cable *cable, int stream) { struct snd_pcm_runtime *runtime, *cruntime; @@ -353,6 +442,13 @@ static void params_change(struct snd_pcm_substream *substream) cable->hw.rate_max = runtime->rate; cable->hw.channels_min = runtime->channels; cable->hw.channels_max = runtime->channels; + + if (cable->snd_timer.instance) { + cable->hw.period_bytes_min = + frames_to_bytes(runtime, runtime->period_size); + cable->hw.period_bytes_max = cable->hw.period_bytes_min; + } + } static int loopback_prepare(struct snd_pcm_substream *substream) @@ -576,6 +672,167 @@ static void loopback_jiffies_timer_function(struct timer_list *t) spin_unlock_irqrestore(&dpcm->cable->lock, flags); } +/* call in cable->lock */ +static int loopback_snd_timer_check_resolution(struct snd_pcm_runtime *runtime, + unsigned long resolution) +{ + if (resolution != runtime->timer_resolution) { + struct loopback_pcm *dpcm = runtime->private_data; + struct loopback_cable *cable = dpcm->cable; + /* Worst case estimation of possible values for resolution + * resolution <= (512 * 1024) frames / 8kHz in nsec + * resolution <= 65.536.000.000 nsec + * + * period_size <= 65.536.000.000 nsec / 1000nsec/usec * 192kHz + + * 500.000 + * period_size <= 12.582.912.000.000 <64bit + * / 1.000.000 usec/sec + */ + snd_pcm_uframes_t period_size_usec = + resolution / 1000 * runtime->rate; + /* round to nearest sample rate */ + snd_pcm_uframes_t period_size = + (period_size_usec + 500 * 1000) / (1000 * 1000); + + pcm_err(dpcm->substream->pcm, + "Period size (%lu frames) of loopback device is not corresponding to timer resolution (%lu nsec = %lu frames) of card timer %d,%d,%d. Use period size of %lu frames for loopback device.", + runtime->period_size, resolution, period_size, + cable->snd_timer.id.card, + cable->snd_timer.id.device, + cable->snd_timer.id.subdevice, + period_size); + return -EINVAL; + } + return 0; +} + +static void loopback_snd_timer_period_elapsed(struct loopback_cable *cable, + int event, + unsigned long resolution) +{ + struct loopback_pcm *dpcm_play, *dpcm_capt; + struct snd_pcm_substream *substream_play, *substream_capt; + struct snd_pcm_runtime *valid_runtime; + unsigned int running, elapsed_bytes; + unsigned long flags; + + spin_lock_irqsave(&cable->lock, flags); + running = cable->running ^ cable->pause; + /* no need to do anything if no stream is running */ + if (!running) { + spin_unlock_irqrestore(&cable->lock, flags); + return; + } + + dpcm_play = cable->streams[SNDRV_PCM_STREAM_PLAYBACK]; + dpcm_capt = cable->streams[SNDRV_PCM_STREAM_CAPTURE]; + substream_play = (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) ? + dpcm_play->substream : NULL; + substream_capt = (running & (1 << SNDRV_PCM_STREAM_CAPTURE)) ? + dpcm_capt->substream : NULL; + + if (event == SNDRV_TIMER_EVENT_MSTOP) { + if (!dpcm_play || + dpcm_play->substream->runtime->status->state != + SNDRV_PCM_STATE_DRAINING) { + spin_unlock_irqrestore(&cable->lock, flags); + return; + } + } + + valid_runtime = (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) ? + dpcm_play->substream->runtime : + dpcm_capt->substream->runtime; + + /* resolution is only valid for SNDRV_TIMER_EVENT_TICK events */ + if (event == SNDRV_TIMER_EVENT_TICK) { + /* The hardware rules guarantee that playback and capture period + * are the same. Therefore only one device has to be checked + * here. + */ + if (loopback_snd_timer_check_resolution(valid_runtime, + resolution) < 0) { + spin_unlock_irqrestore(&cable->lock, flags); + if (substream_play) + snd_pcm_stop_xrun(substream_play); + if (substream_capt) + snd_pcm_stop_xrun(substream_capt); + return; + } + } + + elapsed_bytes = frames_to_bytes(valid_runtime, + valid_runtime->period_size); + /* The same timer interrupt is used for playback and capture device */ + if ((running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) && + (running & (1 << SNDRV_PCM_STREAM_CAPTURE))) { + copy_play_buf(dpcm_play, dpcm_capt, elapsed_bytes); + bytepos_finish(dpcm_play, elapsed_bytes); + bytepos_finish(dpcm_capt, elapsed_bytes); + } else if (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) { + bytepos_finish(dpcm_play, elapsed_bytes); + } else if (running & (1 << SNDRV_PCM_STREAM_CAPTURE)) { + clear_capture_buf(dpcm_capt, elapsed_bytes); + bytepos_finish(dpcm_capt, elapsed_bytes); + } + spin_unlock_irqrestore(&cable->lock, flags); + + if (substream_play) + snd_pcm_period_elapsed(substream_play); + if (substream_capt) + snd_pcm_period_elapsed(substream_capt); +} + +static void loopback_snd_timer_function(struct snd_timer_instance *timeri, + unsigned long resolution, + unsigned long ticks) +{ + struct loopback_cable *cable = timeri->callback_data; + + loopback_snd_timer_period_elapsed(cable, SNDRV_TIMER_EVENT_TICK, + resolution); +} + +static void loopback_snd_timer_tasklet(unsigned long arg) +{ + struct snd_timer_instance *timeri = (struct snd_timer_instance *)arg; + struct loopback_cable *cable = timeri->callback_data; + + loopback_snd_timer_period_elapsed(cable, SNDRV_TIMER_EVENT_MSTOP, 0); +} + +static void loopback_snd_timer_event(struct snd_timer_instance *timeri, + int event, + struct timespec *tstamp, + unsigned long resolution) +{ + /* Do not lock cable->lock here because timer->lock is already hold. + * There are other functions which first lock cable->lock and than + * timer->lock e.g. + * loopback_trigger() + * spin_lock(&cable->lock) + * loopback_snd_timer_start() + * snd_timer_start() + * spin_lock(&timer->lock) + * Therefore when using the oposit order of locks here it could result + * in a deadlock. + */ + + if (event == SNDRV_TIMER_EVENT_MSTOP) { + struct loopback_cable *cable = timeri->callback_data; + + /* sound card of the timer was stopped. Therefore there will not + * be any further timer callbacks. Due to this forward audio + * data from here if in draining state. When still in running + * state the streaming will be aborted by the usual timeout. It + * should not be aborted here because may be the timer sound + * card does only a recovery and the timer is back soon. + * This tasklet triggers loopback_snd_timer_tasklet() + */ + tasklet_schedule(&cable->snd_timer.event_tasklet); + } +} + static void loopback_jiffies_timer_dpcm_info(struct loopback_pcm *dpcm, struct snd_info_buffer *buffer) { @@ -588,6 +845,20 @@ static void loopback_jiffies_timer_dpcm_info(struct loopback_pcm *dpcm, snd_iprintf(buffer, " timer_expires:\t%lu\n", dpcm->timer.expires); } +static void loopback_snd_timer_dpcm_info(struct loopback_pcm *dpcm, + struct snd_info_buffer *buffer) +{ + struct loopback_cable *cable = dpcm->cable; + + snd_iprintf(buffer, " sound timer:\thw:%d,%d,%d\n", + cable->snd_timer.id.card, + cable->snd_timer.id.device, + cable->snd_timer.id.subdevice); + snd_iprintf(buffer, " timer open:\t\t%s\n", + (cable->snd_timer.stream == SNDRV_PCM_STREAM_CAPTURE) ? + "capture" : "playback"); +} + static snd_pcm_uframes_t loopback_pointer(struct snd_pcm_substream *substream) { struct snd_pcm_runtime *runtime = substream->runtime; @@ -706,6 +977,23 @@ static int rule_channels(struct snd_pcm_hw_params *params, return snd_interval_refine(hw_param_interval(params, rule->var), &t); } +static int rule_period_bytes(struct snd_pcm_hw_params *params, + struct snd_pcm_hw_rule *rule) +{ + struct loopback_pcm *dpcm = rule->private; + struct loopback_cable *cable = dpcm->cable; + struct snd_interval t; + + mutex_lock(&dpcm->loopback->cable_lock); + t.min = cable->hw.period_bytes_min; + t.max = cable->hw.period_bytes_max; + mutex_unlock(&dpcm->loopback->cable_lock); + t.openmin = 0; + t.openmax = 0; + t.integer = 0; + return snd_interval_refine(hw_param_interval(params, rule->var), &t); +} + static void free_cable(struct snd_pcm_substream *substream) { struct loopback *loopback = substream->private_data; @@ -748,6 +1036,163 @@ static struct loopback_ops loopback_jiffies_timer_ops = { .dpcm_info = loopback_jiffies_timer_dpcm_info, }; +static int loopback_parse_timer_id(const char *str, + struct snd_timer_id *tid) +{ + /* [<pref>:](<card name>|<card idx>)[{.,}<dev idx>[{.,}<subdev idx>]] */ + const char * const sep_dev = ".,"; + const char * const sep_pref = ":"; + const char *name = str; + char *sep, save = '\0'; + int card_idx = 0, dev = 0, subdev = 0; + int err; + + sep = strpbrk(str, sep_pref); + if (sep) + name = sep + 1; + sep = strpbrk(name, sep_dev); + if (sep) { + save = *sep; + *sep = '\0'; + } + err = kstrtoint(name, 0, &card_idx); + if (err == -EINVAL) { + /* Must be the name, not number */ + for (card_idx = 0; card_idx < snd_ecards_limit; card_idx++) { + struct snd_card *card = snd_card_ref(card_idx); + + if (card) { + if (!strcmp(card->id, name)) + err = 0; + snd_card_unref(card); + } + if (!err) + break; + } + } + if (sep) { + *sep = save; + if (!err) { + char *sep2, save2 = '\0'; + + sep2 = strpbrk(sep + 1, sep_dev); + if (sep2) { + save2 = *sep2; + *sep2 = '\0'; + } + err = kstrtoint(sep + 1, 0, &dev); + if (sep2) { + *sep2 = save2; + if (!err) + err = kstrtoint(sep2 + 1, 0, &subdev); + } + } + } + if (!err && tid) { + tid->card = card_idx; + tid->device = dev; + tid->subdevice = subdev; + } + return err; +} + +/* call in loopback->cable_lock */ +static int loopback_snd_timer_open(struct loopback_pcm *dpcm) +{ + int err = 0; + struct snd_timer_id tid = { + .dev_class = SNDRV_TIMER_CLASS_PCM, + .dev_sclass = SNDRV_TIMER_SCLASS_APPLICATION, + }; + struct snd_timer_instance *timeri; + struct loopback_cable *cable = dpcm->cable; + + spin_lock_irq(&cable->lock); + + /* check if timer was already opened. It is only opened once + * per playback and capture subdevice (aka cable). + */ + if (cable->snd_timer.instance) + goto unlock; + + err = loopback_parse_timer_id(dpcm->loopback->timer_source, &tid); + if (err < 0) { + pcm_err(dpcm->substream->pcm, + "Parsing timer source \'%s\' failed with %d", + dpcm->loopback->timer_source, err); + goto unlock; + } + + cable->snd_timer.stream = dpcm->substream->stream; + cable->snd_timer.id = tid; + + timeri = snd_timer_instance_new(dpcm->loopback->card->id); + if (!timeri) { + err = -ENOMEM; + goto unlock; + } + /* The callback has to be called from another tasklet. If + * SNDRV_TIMER_IFLG_FAST is specified it will be called from the + * snd_pcm_period_elapsed() call of the selected sound card. + * snd_pcm_period_elapsed() helds snd_pcm_stream_lock_irqsave(). + * Due to our callback loopback_snd_timer_function() also calls + * snd_pcm_period_elapsed() which calls snd_pcm_stream_lock_irqsave(). + * This would end up in a dead lock. + */ + timeri->flags |= SNDRV_TIMER_IFLG_AUTO; + timeri->callback = loopback_snd_timer_function; + timeri->callback_data = (void *)cable; + timeri->ccallback = loopback_snd_timer_event; + + /* initialise a tasklet used for draining */ + tasklet_init(&cable->snd_timer.event_tasklet, + loopback_snd_timer_tasklet, (unsigned long)timeri); + + /* snd_timer_close() and snd_timer_open() should not be called with + * locked spinlock because both functions can block on a mutex. The + * mutex loopback->cable_lock is kept locked. Therefore snd_timer_open() + * cannot be called a second time by the other device of the same cable. + * Therefore the following issue cannot happen: + * [proc1] Call loopback_timer_open() -> + * Unlock cable->lock for snd_timer_close/open() call + * [proc2] Call loopback_timer_open() -> snd_timer_open(), + * snd_timer_start() + * [proc1] Call snd_timer_open() and overwrite running timer + * instance + */ + spin_unlock_irq(&cable->lock); + err = snd_timer_open(timeri, &cable->snd_timer.id, current->pid); + spin_lock_irq(&cable->lock); + if (err < 0) { + pcm_err(dpcm->substream->pcm, + "snd_timer_open (%d,%d,%d) failed with %d", + cable->snd_timer.id.card, + cable->snd_timer.id.device, + cable->snd_timer.id.subdevice, + err); + snd_timer_instance_free(timeri); + goto unlock; + } + + cable->snd_timer.instance = timeri; + +unlock: + spin_unlock_irq(&cable->lock); + + return err; +} + +/* stop_sync() is not required for sound timer because it does not need to be + * restarted in loopback_prepare() on Xrun recovery + */ +static struct loopback_ops loopback_snd_timer_ops = { + .open = loopback_snd_timer_open, + .start = loopback_snd_timer_start, + .stop = loopback_snd_timer_stop, + .close_cable = loopback_snd_timer_close_cable, + .dpcm_info = loopback_snd_timer_dpcm_info, +}; + static int loopback_open(struct snd_pcm_substream *substream) { struct snd_pcm_runtime *runtime = substream->runtime; @@ -775,7 +1220,10 @@ static int loopback_open(struct snd_pcm_substream *substream) } spin_lock_init(&cable->lock); cable->hw = loopback_pcm_hardware; - cable->ops = &loopback_jiffies_timer_ops; + if (loopback->timer_source) + cable->ops = &loopback_snd_timer_ops; + else + cable->ops = &loopback_jiffies_timer_ops; loopback->cables[substream->number][dev] = cable; } dpcm->cable = cable; @@ -811,6 +1259,19 @@ static int loopback_open(struct snd_pcm_substream *substream) if (err < 0) goto unlock; + /* In case of sound timer the period time of both devices of the same + * loop has to be the same. + * This rule only takes effect if a sound timer was chosen + */ + if (cable->snd_timer.instance) { + err = snd_pcm_hw_rule_add(runtime, 0, + SNDRV_PCM_HW_PARAM_PERIOD_BYTES, + rule_period_bytes, dpcm, + SNDRV_PCM_HW_PARAM_PERIOD_BYTES, -1); + if (err < 0) + goto unlock; + } + /* loopback_runtime_free() has not to be called if kfree(dpcm) was * already called here. Otherwise it will end up with a double free. */ @@ -1214,6 +1675,18 @@ static int loopback_proc_new(struct loopback *loopback, int cidx) print_cable_info); } +static void loopback_set_timer_source(struct loopback *loopback, + const char *value) +{ + if (loopback->timer_source) { + devm_kfree(loopback->card->dev, loopback->timer_source); + loopback->timer_source = NULL; + } + if (value && *value) + loopback->timer_source = devm_kstrdup(loopback->card->dev, + value, GFP_KERNEL); +} + static int loopback_probe(struct platform_device *devptr) { struct snd_card *card; @@ -1233,6 +1706,8 @@ static int loopback_probe(struct platform_device *devptr) pcm_substreams[dev] = MAX_PCM_SUBSTREAMS; loopback->card = card; + loopback_set_timer_source(loopback, timer_source[dev]); + mutex_init(&loopback->cable_lock); err = loopback_pcm_new(loopback, 0, pcm_substreams[dev]); |