From 64b6acf60b665fffd419c23886a1cbeeb253cfb4 Mon Sep 17 00:00:00 2001 From: Ricardo Biehl Pasquali Date: Fri, 7 Sep 2018 16:58:54 -0300 Subject: [PATCH] ALSA: pcm: Update hardware pointer before start capture This ensures the transfer loop won't waste a run to read the few frames (if any) between start and hw_ptr update. It will wait for the next interrupt with wait_for_avail(). Signed-off-by: Ricardo Biehl Pasquali Signed-off-by: Takashi Iwai --- sound/core/pcm_lib.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c index 7f71c24..40013b2 100644 --- a/sound/core/pcm_lib.c +++ b/sound/core/pcm_lib.c @@ -2172,6 +2172,10 @@ snd_pcm_sframes_t __snd_pcm_lib_xfer(struct snd_pcm_substream *substream, if (err < 0) goto _end_unlock; + runtime->twake = runtime->control->avail_min ? : 1; + if (runtime->status->state == SNDRV_PCM_STATE_RUNNING) + snd_pcm_update_hw_ptr(substream); + if (!is_playback && runtime->status->state == SNDRV_PCM_STATE_PREPARED) { if (size >= runtime->start_threshold) { @@ -2185,10 +2189,8 @@ snd_pcm_sframes_t __snd_pcm_lib_xfer(struct snd_pcm_substream *substream, } } - runtime->twake = runtime->control->avail_min ? : 1; - if (runtime->status->state == SNDRV_PCM_STATE_RUNNING) - snd_pcm_update_hw_ptr(substream); avail = snd_pcm_avail(substream); + while (size > 0) { snd_pcm_uframes_t frames, appl_ptr, appl_ofs; snd_pcm_uframes_t cont; -- 2.7.4