On Wed, Feb 06, 2019 at 12:14:56PM +0100, Krzysztof Kozlowski wrote:
On Wed, 6 Feb 2019 at 12:00, Charles Keepax ckeepax@opensource.cirrus.com wrote:
On Wed, Feb 06, 2019 at 11:22:33AM +0100, Krzysztof Kozlowski wrote:
On Wed, 6 Feb 2019 at 11:05, Charles Keepax ckeepax@opensource.cirrus.com wrote:
DAIs linked to the dummy will not have an associated playback/capture widget, so we need to skip the update in that case.
Fixes: 078a85f2806f ("ASoC: dapm: Only power up active channels from a DAI") Signed-off-by: Charles Keepax ckeepax@opensource.cirrus.com
Ok so that all makes sense, this patch is probably the best fix?
Thanks, Charles
For this particular issue (NULL-pointer): Reported-by: Krzysztof Kozlowski krzk@kernel.org Tested-by: Krzysztof Kozlowski krzk@kernel.org
However now I see bug sleeping in atomic context:
[ 64.000828] BUG: sleeping function called from invalid context at ../kernel/locking/mutex.c:908
Does this probably definitely get fixed by reverting my patch? It's just a bit odd as this seems to be complaining about a clock operation in i2s_trigger and I don't think my patch should have any affect on the trigger callback. It should get run from either the dai_link DAPM event or hw_params, neither of which should happen in an atomic context.
Before this fixup, probably NULL pointer happened before any of this. I tried it now few times and the possible deadlock and sleeping in invalid context did not appear. It might be random/racy or totally unrelated to your change.
Looking through I think this is an unrelated issue. Assuming the driver in question is (sound/soc/samsung/i2s.c). Inside i2s_trigger, there is a call to config_setup(i2s), which in turn will call clk_get_rate if i2s->quirks contains the flag QUIRK_NO_MUXPSR.
The trigger callback can be made from an atomic context and clk_get_rate will take the prepare lock of the clock. The clock prepare lock is always a mutex which shouldn't be locked from an atomic context. So it seems like this will fail whenever that QUIRK_NO_MUXPSR flag is set, no idea what causes that to be set.
It looks like this bug was introduced by this change:
647d04f8e07a ("ASoC: samsung: i2s: Ensure the RCLK rate is properly determined")
Thanks, Charles