From 53451b6da8271905941eb1eb369db152c4bd92f2 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Mon, 11 Oct 2021 12:36:50 +0200 Subject: 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 --- sound/usb/pcm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'sound/usb') 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 */ -- cgit