Messages in this thread | | | Subject | Re: [alsa-devel] [PATCH v2] soundwire: stream: fix bad unlock balance | From | Srinivas Kandagatla <> | Date | Thu, 6 Jun 2019 15:58:33 +0100 |
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On 06/06/2019 15:28, Pierre-Louis Bossart wrote: > On 6/6/19 6:22 AM, Srinivas Kandagatla wrote: >> multi bank switching code takes lock on condition but releases without >> any check resulting in below warning. >> This patch fixes this. > > > Question to make sure we are talking about the same thing: multi-link > bank switching is a capability beyond the scope of the SoundWire spec > which requires hardware support to synchronize links and as Sanyog > hinted at in a previous email follow a different flow for bank switches. > > You would not use the multi-link mode if you have different links that > can operate independently and have no synchronization requirement. You > would conversely use the multi-link mode if you have two devices on the > same type on different links and want audio to be rendered at the same > time. > > Can you clarify if indeed you were using the full-blown multi-link mode > with hardware synchronization or a regular single-link operation? I am > not asking for details of your test hardware, just trying to reconstruct > the program flow leading to this problem. >
Am testing on a regular single link, which hits this path.
> It could also be that your commit message was meant to say: > "the msg lock is taken for multi-link cases only but released > unconditionally, leading to an unlock balance warning for single-link > usages"? Yes. Vinod can update comment while applying this patch? If not I can respin with correct log.
thanks, srini
> > Thanks! > >> >> ===================================== >> 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@linaro.org> >> --- >> 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 ce9cb7fa4724..73c52cd4fec8 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 (bus->multi_link) >> + mutex_unlock(&bus->msg_lock); >> } >> return ret; >> >
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