[pulseaudio-discuss] [PATCH] alsa: remove double calls of snd_pcm_prepare()

[Tanu Kaskinen]

On Fri, 2016-12-30 at 12:05 +0900, Takashi Sakamoto wrote:
> In alsa-lib, snd_pcm_hw_params() internally calls snd_pcm_prepare(), thus
> user space applications have no need to call snd_pcm_prepare() after calls
> of snd_pcm_hw_params(). An explicit calls of snd_pcm_prepare() is expected
> in a case to recover PCM substreams.
> 
> Current implementation of PulseAudio modules for ALSA playbacking/capturing
> results in double calls of snd_pcm_prepare(). The second call for hw plugin
> of alsa-lib executes ioctl(2) with SNDRV_PCM_IOCTL_PREPARE command in state
> of SNDRV_PCM_STATE_PREPARED for the PCM substream. This has no effects to
> the PCM substream as long as corresponding drivers are implemented
> correctly.
> 
> This commit removes the second call for the reason.
> 
> Signed-off-by: Takashi Sakamoto <o-takashi at sakamocchi.jp>
> ---
>  src/modules/alsa/alsa-util.c | 5 -----
>  src/tests/alsa-time-test.c   | 3 ---
>  2 files changed, 8 deletions(-)

Thanks! Applied in the "next" branch.

-- 
Tanu

https://www.patreon.com/tanuk