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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/endpoint.h | |
| parent | d5f871f89e21bb71827ea57bd484eedea85839a0 (diff) | |
| download | lwn-813a17cab9b708bbb1e0db8902e19857b57196ec.tar.gz lwn-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/endpoint.h')
| -rw-r--r-- | sound/usb/endpoint.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/sound/usb/endpoint.h b/sound/usb/endpoint.h index 6895d50d14d1..6a9af04cf175 100644 --- a/sound/usb/endpoint.h +++ b/sound/usb/endpoint.h @@ -38,7 +38,7 @@ void snd_usb_endpoint_set_callback(struct snd_usb_endpoint *ep, struct snd_usb_substream *data_subs); int snd_usb_endpoint_start(struct snd_usb_endpoint *ep); -void snd_usb_endpoint_stop(struct snd_usb_endpoint *ep); +void snd_usb_endpoint_stop(struct snd_usb_endpoint *ep, bool keep_pending); void snd_usb_endpoint_sync_pending_stop(struct snd_usb_endpoint *ep); void snd_usb_endpoint_suspend(struct snd_usb_endpoint *ep); int snd_usb_endpoint_activate(struct snd_usb_endpoint *ep); |