On 24-11-20, 21:07, Bard Liao wrote:
From: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com
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 In practice, the master device will suspend when all its children are no longer active.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