On Wed, Dec 20, 2017 at 3:09 PM, Ulf Hansson <ulf.hansson@xxxxxxxxxx> wrote: > The runtime PM deployment in the phy core is deployed using the phy core > device, which is created by the phy core and assigned as a child device of > the phy provider device. > > The behaviour around the runtime PM deployment cause some issues during > system suspend, in cases when the phy provider device is put into a low > power state via a call to the pm_runtime_force_suspend() helper, as is the > case for a Renesas SoC, which has its phy provider device attached to the > generic PM domain. > > In more detail, the problem in this case is that pm_runtime_force_suspend() > expects the child device of the provider device, which is the phy core > device, to be runtime suspended, else a WARN splat will be printed > (correctly) when runtime PM gets re-enabled at system resume. So we are now trying to work around issues with pm_runtime_force_suspend(). Lovely. :-/ > In the current scenario, even if a call to phy_power_off() triggers it to > invoke pm_runtime_put() during system suspend, the phy core device doesn't > get runtime suspended, because this is prevented in the system suspend > phases by the PM core. > > To solve this problem, let's move the runtime PM deployment from the phy > core device to the phy provider device, as this provides the similar > behaviour. Changing this makes it redundant to enable runtime PM for the > phy core device, so let's avoid doing that. I'm not really convinced that this approach is the best one to be honest. I'll have a deeper look at this in the next few days, stay tuned. Thanks, Rafael
