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| author | Takashi Iwai <tiwai@suse.de> | 2021-10-11 12:36:50 +0200 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2021-10-12 14:32:46 +0200 |
| commit | 53451b6da8271905941eb1eb369db152c4bd92f2 (patch) | |
| tree | a74735bf09aa103b55a1f948c1bf173c03177e30 /sound/usb | |
| parent | 6d27788160362a7ee6c0d317636fe4b1ddbe59a7 (diff) | |
| download | lwn-53451b6da8271905941eb1eb369db152c4bd92f2.tar.gz lwn-53451b6da8271905941eb1eb369db152c4bd92f2.zip | |
ALSA: usb-audio: Less restriction for low-latency playback mode
The recent support for the improved low-latency playback mode applied
the SNDRV_PCM_INFO_EXPLICIT_SYNC flag for the target streams, but this
was a slight overkill. The use of the flag above disables effectively
both PCM status and control mmaps, while basically what we want to
track is only about the appl_ptr update.
For less restriction, use a more proper flag,
SNDRV_PCM_INFO_SYNC_APPLPTR instead, which disables only the control
mmap.
Fixes: d5f871f89e21 ("ALSA: usb-audio: Improved lowlatency playback support")
Link: https://lore.kernel.org/r/20211011103650.10182-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/usb')
| -rw-r--r-- | sound/usb/pcm.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c index 3bb095a3c9b6..95ec8eec1bb0 100644 --- a/sound/usb/pcm.c +++ b/sound/usb/pcm.c @@ -1102,7 +1102,7 @@ static int snd_usb_pcm_open(struct snd_pcm_substream *substream) /* need an explicit sync to catch applptr update in low-latency mode */ if (direction == SNDRV_PCM_STREAM_PLAYBACK && as->chip->lowlatency) - runtime->hw.info |= SNDRV_PCM_INFO_EXPLICIT_SYNC; + runtime->hw.info |= SNDRV_PCM_INFO_SYNC_APPLPTR; runtime->private_data = subs; subs->pcm_substream = substream; /* runtime PM is also done there */ |