File 0015-pcm-direct-Fix-deadlock-in-poll_descriptors.patch of Package alsa.openSUSE_Leap_42.2_Update

From 24e63b75275e9c923c336b8dba3919b980e8f234 Mon Sep 17 00:00:00 2001
From: Takashi Iwai <tiwai@suse.de>
Date: Mon, 16 Jan 2017 16:21:52 +0100
Subject: [PATCH 15/43] 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 <tiwai@suse.de>
---
 src/pcm/pcm_direct.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/src/pcm/pcm_direct.c
+++ b/src/pcm/pcm_direct.c
@@ -676,7 +676,8 @@ int snd_pcm_direct_poll_descriptors(snd_
 	}
 
 	/* 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: