Re: [PATCH] soundwire: master: use pm_runtime_set_active() on add

From: Vinod Koul
Date: Wed Dec 02 2020 - 02:20:50 EST


On 24-11-20, 21:07, Bard Liao wrote:
> From: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
>
> The 'master' device acts as a glue layer used during bus
> initialization only, and it needs to be 'transparent' for pm_runtime
> management. Its behavior should be that it becomes active when one of
> its children becomes active, and suspends when all of its children are
> suspended.
>
> In our tests on Intel platforms, we routinely see these sort of
> warnings on the initial boot:
>
> [ 21.447345] rt715 sdw:3:25d:715:0: runtime PM trying to activate
> child device sdw:3:25d:715:0 but parent (sdw-master-3) is not active
>
> This is root-caused to a missing setup to make the device 'active' on
> probe. Since we don't want the device to remain active forever after
> the probe, the autosuspend configuration is also enabled at the end of
> the probe - the device will actually autosuspend only in the case
> where there are no devices physically attached. In practice, the
> master device will suspend when all its children are no longer active.

Applied, thanks

--
~Vinod