[PATCH 5.1 031/138] soundwire: stream: fix bad unlock balance

[Greg Kroah-Hartman]

[ Upstream commit 9315d904c7e8f38886e2820fa6cb8d0fa723ea21 ]

the msg lock is taken for multi-link cases only but released
unconditionally, leading to an unlock balance warning for single-link usages
This patch fixes this.

 =====================================
 WARNING: bad unlock balance detected!
 5.1.0-16506-gc1c383a6f0a2-dirty #1523 Tainted: G        W
 -------------------------------------
 aplay/2954 is trying to release lock (&bus->msg_lock) at:
 do_bank_switch+0x21c/0x480
 but there are no more locks to release!

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
Acked-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
Acked-by: Sanyog Kale <sanyog.r.kale@xxxxxxxxx>
[vkoul: edited the change log as suggested by Pierre]
Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/soundwire/stream.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/soundwire/stream.c b/drivers/soundwire/stream.c
index 00618de2ee12..794ced434cf2 100644
--- a/drivers/soundwire/stream.c
+++ b/drivers/soundwire/stream.c
@@ -805,7 +805,8 @@ static int do_bank_switch(struct sdw_stream_runtime *stream)
 			goto error;
 		}
 
-		mutex_unlock(&bus->msg_lock);
+		if (bus->multi_link)
+			mutex_unlock(&bus->msg_lock);
 	}
 
 	return ret;
-- 
2.20.1