From mboxrd@z Thu Jan 1 00:00:00 1970 From: Shengjiu Wang Subject: Re: [PATCH] PCM: snd_pcm_dmix_drain() maybe blocked after suspend and resume Date: Tue, 9 Jun 2015 10:35:41 +0800 Message-ID: <20150609023539.GA3277@shlinux2> References: <1433756291-22999-1-git-send-email-shengjiu.wang@freescale.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from na01-bn1-obe.outbound.protection.outlook.com (mail-bn1on0113.outbound.protection.outlook.com [157.56.110.113]) by alsa0.perex.cz (Postfix) with ESMTP id D1A36261B01 for ; Tue, 9 Jun 2015 04:37:27 +0200 (CEST) Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: Takashi Iwai Cc: alsa-devel@alsa-project.org List-Id: alsa-devel@alsa-project.org On Mon, Jun 08, 2015 at 01:31:41PM +0200, Takashi Iwai wrote: > At Mon, 8 Jun 2015 17:38:11 +0800, > Shengjiu Wang wrote: > > > > After suspend and resume, the alsa driver is stopped. But if alsa-lib run > > into snd_pcm_dmix_drain(), it need to wait avail >= pcm->stop_threshold, > > otherwise, it will not exit the loop, so finally it is blocked at poll() of > > snd_pcm_wait_nocheck(pcm, -1). > > This patch is to add state check after snd_pcm_wait_nocheck(pcm, -1), if > > the state is SND_PCM_STATE_SUSPENDED, then return error. > > > > Signed-off-by: Shengjiu Wang > > --- > > src/pcm/pcm_dmix.c | 6 ++++++ > > 1 file changed, 6 insertions(+) > > > > diff --git a/src/pcm/pcm_dmix.c b/src/pcm/pcm_dmix.c > > index babde6a..0cc318e 100644 > > --- a/src/pcm/pcm_dmix.c > > +++ b/src/pcm/pcm_dmix.c > > @@ -647,6 +647,12 @@ static int snd_pcm_dmix_drain(snd_pcm_t *pcm) > > if (dmix->state == SND_PCM_STATE_DRAINING) { > > snd_pcm_dmix_sync_area(pcm); > > snd_pcm_wait_nocheck(pcm, -1); > > + switch (snd_pcm_state(pcm)) { > > It's better (shorter) to call snd_pcm_state(dmix->spcm) in this case. > > And, I think we should have the check of SND_PCM_STATE_SUSPENDED at > the beginning of snd_pcm_dmix_drain() before entering to the loop, > too. > > Last but not least, the very same bug is present for dshare. Could > you fix this together? > Ok, I will refine the patch. But one thing I don't understand is that why need to check the SND_PCM_STATE_SUSPENDED before entering the loop, seems check the state in the loop can resolve the issue. Best regards wang shengjiu > > thanks, > > Takashi > > > + case SND_PCM_STATE_SUSPENDED: > > + return -ESTRPIPE; > > + default: > > + break; > > + } > > snd_pcm_direct_clear_timer_queue(dmix); /* force poll to wait */ > > } > > } while (dmix->state == SND_PCM_STATE_DRAINING); > > -- > > 1.7.9.5 > >