The driver may sleep under a spin lock, and the function call path is:
midi_outc (acquire the lock by spin_lock_irqsave)
oss_broken_sleep_on
schedule_timeout --> may sleep
To fix it, the lock is released before oss_broken_sleep_on, and the lock
is acquired again after this function.
Signed-off-by: Jia-Ju Bai <[email protected]>
---
sound/oss/sequencer.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/sound/oss/sequencer.c b/sound/oss/sequencer.c
index f19da4b..3d95d752 100644
--- a/sound/oss/sequencer.c
+++ b/sound/oss/sequencer.c
@@ -1211,7 +1211,9 @@ static void midi_outc(int dev, unsigned char data)
spin_lock_irqsave(&lock,flags);
while (n && !midi_devs[dev]->outputc(dev, data)) {
+ spin_unlock_irqrestore(&lock, flags);
oss_broken_sleep_on(&seq_sleeper, HZ/25);
+ spin_lock_irqsave(&lock, flags);
n--;
}
spin_unlock_irqrestore(&lock,flags);
--
1.7.9.5