On Thu, May 23, 2019 at 09:43:14AM +0100, Srinivas Kandagatla wrote: > > > On 22/05/2019 17:41, Pierre-Louis Bossart wrote: > > > > > > On 5/22/19 11:25 AM, Srinivas Kandagatla wrote: > > > This patch fixes below warning due to unlocking without locking. > > > > > > ?? ===================================== > > > ?? 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> > > > --- > > > ?? 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 544925ff0b40..d16268f30e4f 100644 > > > --- a/drivers/soundwire/stream.c > > > +++ b/drivers/soundwire/stream.c > > > @@ -814,7 +814,8 @@ static int do_bank_switch(struct > > > sdw_stream_runtime *stream) > > > ?????????????????????????? goto error; > > > ?????????????????? } > > > -?????????????? mutex_unlock(&bus->msg_lock); > > > +?????????????? if (mutex_is_locked(&bus->msg_lock)) > > > +?????????????????????? utex_unlock(&bus->msg_lock); > > > > Does this even compile? should be mutex_unlock, no? > > > > We also may want to identify the issue in more details without pushing > > it under the rug. The locking mechanism is far from simple and it's > > likely there are a number of problems with it. > > > msg_lock is taken conditionally during multi link bank switch cases, however > the unlock is done unconditionally leading to this warning. > > Having a closer look show that there could be a dead lock in this path while > executing sdw_transfer(). And infact there is no need to take msg_lock in > multi link switch cases as sdw_transfer should take care of this. > > Vinod/Sanyog any reason why msg_lock is really required in this path? > In case of multi link we use sdw_transfer_defer instead of sdw_transfer where lock is not acquired, hence lock is acquired in do_bank_switch for multi link. we should add same check of multi link to release lock in do_bank_switch. > --srini > > > > ?????????? } > > > ?????????? return ret; > > > -- _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx https://mailman.alsa-project.org/mailman/listinfo/alsa-devel
