[...] >> >>>> Second, have you considered setting the default value of >>>> dev->power.may_skip_resume to true? >>> >>> Yes. >>> >>>> That would means the subsystem >>>> instead need to implement an opt-out method. I am thinking that it may >>>> not be an issue, since we anyway at this point, don't have drivers >>>> using the LEAVE_SUSPENDED flag. >>> >>> Opt-out doesn't work because of the need to invoke the "noirq" callbacks. >> >> I am not sure I follow that. >> >> Whatever needs to be fixed on the subsystem level, that could be done >> before the driver starts using the LEAVE_SUSPENDED flag. No? > > That requires a bit of explanation, sorry for being overly concise. > > The core calls ->resume_noirq from the middle layer regardless of > whether or not the device will be left suspended, so the > ->resume_noirq cannot do arbitrary things to it. Setting > may_skip_resume by the middle layer tells the core that the middle > layer is ready for that and is going to cooperate. If may_skip_resume > had been set by default, that piece of information would have been > missing. Huh, I still don't get that. Sorry. If the "may_skip_resume" is default set to true by the PM core, wouldn't that just mean that the middle-layer needs to implement an opt-out method, rather than opt-in. In principle to opt-out the middle-layer needs to set may_skip_resume to false in suspend_noirq phase, no? Then we only need to make sure drivers don't starts use LEAVE_SUSPENDED, before we make sure the middle layers is adopted. But that should not be a problem. The benefit would be that those middle layers that can cope with LEAVE_SUSPENDED as of today don't need to change. Kind regards Uffe
