From 24e63b75275e9c923c336b8dba3919b980e8f234 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Mon, 16 Jan 2017 16:21:52 +0100 Subject: [PATCH] pcm: direct: Fix deadlock in poll_descriptors The recent change in PCM direct plugins to check XRUN in poll_descriptors callback caused a regression; as consequence, the whole playback hangs up. The culprit is a mutex dead lock by the call in snd_pcm_state() inside the new snd_pcm_direct_poll_descriptors(). The poll_descriptors code path is protected with pcm mutex, thus an unlocked version (__snd_pcm_state()) has to be used inside the callback instead. Fixes: 789ee39727a1 ("pcm: direct: check state before enter poll on timer") Signed-off-by: Takashi Iwai --- src/pcm/pcm_direct.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/src/pcm/pcm_direct.c b/src/pcm/pcm_direct.c index f4d7c3f2..e4bef786 100644 --- a/src/pcm/pcm_direct.c +++ b/src/pcm/pcm_direct.c @@ -676,7 +676,8 @@ int snd_pcm_direct_poll_descriptors(snd_pcm_t *pcm, struct pollfd *pfds, } /* this will also evaluate slave state and enter xrun if necessary */ - switch (snd_pcm_state(pcm)) { + /* using __snd_pcm_state() since this function is called inside lock */ + switch (__snd_pcm_state(pcm)) { case SND_PCM_STATE_XRUN: return -EPIPE; default: -- 2.47.3