From mboxrd@z Thu Jan 1 00:00:00 1970 From: Koro Chen Subject: [PATCH] ASoC: dpcm: Make BE prepare possible in suspend state Date: Wed, 28 Oct 2015 10:15:34 +0800 Message-ID: <1445998534-38246-1-git-send-email-koro.chen@mediatek.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: 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: broonie@kernel.org, tiwai@suse.de Cc: alsa-devel@alsa-project.org, srv_heupstream@mediatek.com, s.hauer@pengutronix.de, linux-kernel@vger.kernel.org, liam.r.girdwood@linux.intel.com, Koro Chen , linux-mediatek@lists.infradead.org, linux-arm-kernel@lists.infradead.org List-Id: linux-mediatek@lists.infradead.org During suspend/resume, there is a flow that if a driver does not support SNDRV_PCM_INFO_RESUME, it will fail at snd_pcm_resume(), and user space can then issue SNDRV_PCM_IOCTL_PREPARE to let audio continue to play. However, in dpcm_be_dai_prepare() it only allows BEs to be prepared in state SND_SOC_DPCM_STATE_HW_PARAMS or SND_SOC_DPCM_STATE_STOP. The BE state will then stay in SND_SOC_DPCM_STATE_SUSPEND, consequently dpcm_be_dai_shutdown() is skipped in the end of playback and be_substream->runtime is not cleared while this runtime is actually freed by snd_pcm_detach_substream(). If another suspend comes, a NULL pointer dereference will happen in snd_pcm_suspend() when accessing BE substream's runtime. Signed-off-by: Koro Chen --- sound/soc/soc-pcm.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/sound/soc/soc-pcm.c b/sound/soc/soc-pcm.c index 3173958..5c41a58 100644 --- a/sound/soc/soc-pcm.c +++ b/sound/soc/soc-pcm.c @@ -2117,7 +2117,8 @@ int dpcm_be_dai_prepare(struct snd_soc_pcm_runtime *fe, int stream) continue; if ((be->dpcm[stream].state != SND_SOC_DPCM_STATE_HW_PARAMS) && - (be->dpcm[stream].state != SND_SOC_DPCM_STATE_STOP)) + (be->dpcm[stream].state != SND_SOC_DPCM_STATE_STOP) && + (be->dpcm[stream].state != SND_SOC_DPCM_STATE_SUSPEND)) continue; dev_dbg(be->dev, "ASoC: prepare BE %s\n", -- 1.7.9.5