Re: [PATCH] ASoC: rsnd: stop all working stream when .remove

Takashi Iwai
2017-09-01T07:29:55Z

On Fri, 01 Sep 2017 06:34:48 +0200,
Kuninori Morimoto wrote:
>
>
> From: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
>
> Driver should stop all working stream when .remove timing.
> Current Renesas sound driver is assuming that all stream was
> stopped when .remove but it was wrong.
> This patch stops all working stream when .remove, otherwise
> kernel will get damage for example in below case.
> Special thanks to Truong, Hiep
>
> > cd /sys/bus/platform/drivers/rcar_sound
> > aplay xxx.wav &
> > echo ec500000.sound > unbind
>
> Reported-by: Hiep Cao Minh <cm-hiep@jinso.co.jp>
> Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>

The lack of stop sync is a known problem in the ALSA PCM
infrastructure. The standard idiom is to do sync at both prepare and
hw_free (or close) callbacks.

Takashi