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| author | Takashi Iwai <tiwai@suse.de> | 2021-09-29 10:08:44 +0200 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2021-09-30 13:55:26 +0200 |
| commit | 813a17cab9b708bbb1e0db8902e19857b57196ec (patch) | |
| tree | f91282e2fbb445a1d96d873bce133dd75b8043a1 /sound/usb/pcm.c | |
| parent | ALSA: usb-audio: Improved lowlatency playback support (diff) | |
| download | linux-813a17cab9b708bbb1e0db8902e19857b57196ec.tar.xz linux-813a17cab9b708bbb1e0db8902e19857b57196ec.zip | |
ALSA: usb-audio: Avoid killing in-flight URBs during draining
While draining a stream, ALSA PCM core stops the stream by issuing
snd_pcm_stop() after all data has been sent out. And, at PCM trigger
stop, currently USB-audio driver kills the in-flight URBs explicitly,
then at sync-stop ops, sync with the finish of all remaining URBs.
This might result in a drop of the drained samples as most of
USB-audio devices / hosts allow relatively long in-flight samples (as
a sort of FIFO).
For avoiding the trimming, this patch changes the stream-stop behavior
during PCM draining state. Under that condition, the pending URBs
won't be killed. The leftover in-flight URBs are caught by the
sync-stop operation that shall be performed after the trigger-stop
operation.
Link: https://lore.kernel.org/r/20210929080844.11583-10-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/usb/pcm.c')
| -rw-r--r-- | sound/usb/pcm.c | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c index d5a14e5b9ad3..f09c7380a923 100644 --- a/sound/usb/pcm.c +++ b/sound/usb/pcm.c @@ -219,16 +219,16 @@ int snd_usb_init_pitch(struct snd_usb_audio *chip, return 0; } -static bool stop_endpoints(struct snd_usb_substream *subs) +static bool stop_endpoints(struct snd_usb_substream *subs, bool keep_pending) { bool stopped = 0; if (test_and_clear_bit(SUBSTREAM_FLAG_SYNC_EP_STARTED, &subs->flags)) { - snd_usb_endpoint_stop(subs->sync_endpoint); + snd_usb_endpoint_stop(subs->sync_endpoint, keep_pending); stopped = true; } if (test_and_clear_bit(SUBSTREAM_FLAG_DATA_EP_STARTED, &subs->flags)) { - snd_usb_endpoint_stop(subs->data_endpoint); + snd_usb_endpoint_stop(subs->data_endpoint, keep_pending); stopped = true; } return stopped; @@ -261,7 +261,7 @@ static int start_endpoints(struct snd_usb_substream *subs) return 0; error: - stop_endpoints(subs); + stop_endpoints(subs, false); return err; } @@ -437,7 +437,7 @@ static int configure_endpoints(struct snd_usb_audio *chip, if (subs->data_endpoint->need_setup) { /* stop any running stream beforehand */ - if (stop_endpoints(subs)) + if (stop_endpoints(subs, false)) sync_pending_stops(subs); err = snd_usb_endpoint_configure(chip, subs->data_endpoint); if (err < 0) @@ -572,7 +572,7 @@ static int snd_usb_hw_free(struct snd_pcm_substream *substream) subs->cur_audiofmt = NULL; mutex_unlock(&chip->mutex); if (!snd_usb_lock_shutdown(chip)) { - if (stop_endpoints(subs)) + if (stop_endpoints(subs, false)) sync_pending_stops(subs); close_endpoints(chip, subs); snd_usb_unlock_shutdown(chip); @@ -1559,7 +1559,7 @@ static int snd_usb_substream_playback_trigger(struct snd_pcm_substream *substrea return 0; case SNDRV_PCM_TRIGGER_SUSPEND: case SNDRV_PCM_TRIGGER_STOP: - stop_endpoints(subs); + stop_endpoints(subs, substream->runtime->status->state == SNDRV_PCM_STATE_DRAINING); snd_usb_endpoint_set_callback(subs->data_endpoint, NULL, NULL, NULL); subs->running = 0; @@ -1607,7 +1607,7 @@ static int snd_usb_substream_capture_trigger(struct snd_pcm_substream *substream return 0; case SNDRV_PCM_TRIGGER_SUSPEND: case SNDRV_PCM_TRIGGER_STOP: - stop_endpoints(subs); + stop_endpoints(subs, false); fallthrough; case SNDRV_PCM_TRIGGER_PAUSE_PUSH: snd_usb_endpoint_set_callback(subs->data_endpoint, |