The current PCM core has the following problems regarding PCM draining in non-blocking mode:

- the current f_flags isn't checked in snd_pcm_drain(), thus changing the mode dynamically via snd_pcm_nonblock() after open doesn't work. - calling drain in non-blocking mode just return -EAGAIN error, but doesn't provide any way to sync with draining.

This patch fixes these issues. - check file->f_flags in snd_pcm_drain() properly - when O_NONBLOCK is set, PCM core sets the stream(s) to DRAIN state but quits ioctl immediately without waiting the whole drain; the caller can sync the drain manually via poll()

Signed-off-by: Takashi Iwai tiwai@suse.de --- sound/core/pcm_lib.c | 12 +++++++--- sound/core/pcm_native.c | 52 ++++++++++++++++++++++++++-------------------- 2 files changed, 37 insertions(+), 27 deletions(-)

diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c index 72cfd47..e3e78c7 100644 --- a/sound/core/pcm_lib.c +++ b/sound/core/pcm_lib.c @@ -197,12 +197,16 @@ static int snd_pcm_update_hw_ptr_post(struct snd_pcm_substream *substream, avail = snd_pcm_capture_avail(runtime); if (avail > runtime->avail_max) runtime->avail_max = avail; - if (avail >= runtime->stop_threshold) { - if (substream->runtime->status->state == SNDRV_PCM_STATE_DRAINING) + if (runtime->status->state == SNDRV_PCM_STATE_DRAINING) { + if (avail >= runtime->buffer_size) { snd_pcm_drain_done(substream); - else + return -EPIPE; + } + } else { + if (avail >= runtime->stop_threshold) { xrun(substream); - return -EPIPE; + return -EPIPE; + } } if (avail >= runtime->control->avail_min) wake_up(&runtime->sleep); diff --git a/sound/core/pcm_native.c b/sound/core/pcm_native.c index ac2150e..b08898c 100644 --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -1343,8 +1343,6 @@ static int snd_pcm_prepare(struct snd_pcm_substream *substream,

static int snd_pcm_pre_drain_init(struct snd_pcm_substream *substream, int state) { - if (substream->f_flags & O_NONBLOCK) - return -EAGAIN; substream->runtime->trigger_master = substream; return 0; } @@ -1392,7 +1390,6 @@ static struct action_ops snd_pcm_action_drain_init = { struct drain_rec { struct snd_pcm_substream *substream; wait_queue_t wait; - snd_pcm_uframes_t stop_threshold; };

static int snd_pcm_drop(struct snd_pcm_substream *substream); @@ -1404,13 +1401,15 @@ static int snd_pcm_drop(struct snd_pcm_substream *substream); * After this call, all streams are supposed to be either SETUP or DRAINING * (capture only) state. */ -static int snd_pcm_drain(struct snd_pcm_substream *substream) +static int snd_pcm_drain(struct snd_pcm_substream *substream, + struct file *file) { struct snd_card *card; struct snd_pcm_runtime *runtime; struct snd_pcm_substream *s; int result = 0; int i, num_drecs; + int nonblock = 0; struct drain_rec *drec, drec_tmp, *d;

card = substream->pcm->card; @@ -1428,6 +1427,15 @@ static int snd_pcm_drain(struct snd_pcm_substream *substream) } }

+ if (file) { + if (file->f_flags & O_NONBLOCK) + nonblock = 1; + } else if (substream->f_flags & O_NONBLOCK) + nonblock = 1; + + if (nonblock) + goto lock; /* no need to allocate waitqueues */ + /* allocate temporary record for drain sync */ down_read(&snd_pcm_link_rwsem); if (snd_pcm_stream_linked(substream)) { @@ -1449,16 +1457,11 @@ static int snd_pcm_drain(struct snd_pcm_substream *substream) d->substream = s; init_waitqueue_entry(&d->wait, current); add_wait_queue(&runtime->sleep, &d->wait); - /* stop_threshold fixup to avoid endless loop when - * stop_threshold > buffer_size - */ - d->stop_threshold = runtime->stop_threshold; - if (runtime->stop_threshold > runtime->buffer_size) - runtime->stop_threshold = runtime->buffer_size; } } up_read(&snd_pcm_link_rwsem);

+ lock: snd_pcm_stream_lock_irq(substream); /* resume pause */ if (substream->runtime->status->state == SNDRV_PCM_STATE_PAUSED) @@ -1466,9 +1469,12 @@ static int snd_pcm_drain(struct snd_pcm_substream *substream)

/* pre-start/stop - all running streams are changed to DRAINING state */ result = snd_pcm_action(&snd_pcm_action_drain_init, substream, 0); - if (result < 0) { - snd_pcm_stream_unlock_irq(substream); - goto _error; + if (result < 0) + goto unlock; + /* in non-blocking, we don't wait in ioctl but let caller poll */ + if (nonblock) { + result = -EAGAIN; + goto unlock; }

for (;;) { @@ -1504,18 +1510,18 @@ static int snd_pcm_drain(struct snd_pcm_substream *substream) } }

+ unlock: snd_pcm_stream_unlock_irq(substream);

- _error: - for (i = 0; i < num_drecs; i++) { - d = &drec[i]; - runtime = d->substream->runtime; - remove_wait_queue(&runtime->sleep, &d->wait); - runtime->stop_threshold = d->stop_threshold; + if (!nonblock) { + for (i = 0; i < num_drecs; i++) { + d = &drec[i]; + runtime = d->substream->runtime; + remove_wait_queue(&runtime->sleep, &d->wait); + } + if (drec != &drec_tmp) + kfree(drec); } - - if (drec != &drec_tmp) - kfree(drec); snd_power_unlock(card);

return result; @@ -2544,7 +2550,7 @@ static int snd_pcm_common_ioctl1(struct file *file, return snd_pcm_hw_params_old_user(substream, arg); #endif case SNDRV_PCM_IOCTL_DRAIN: - return snd_pcm_drain(substream); + return snd_pcm_drain(substream, file); case SNDRV_PCM_IOCTL_DROP: return snd_pcm_drop(substream); case SNDRV_PCM_IOCTL_PAUSE: