PM regression with commit 5de85b9d57ab PM runtime re-init in v4.5-rc1

[Tony Lindgren]

* Rafael J. Wysocki <rafael at kernel.org> [160126 15:38]:
> On Wed, Jan 27, 2016 at 12:22 AM, Tony Lindgren <tony at atomide.com> wrote:
> > * Rafael J. Wysocki <rafael at kernel.org> [160126 15:15]:
> >> On Tue, Jan 26, 2016 at 11:48 PM, Tony Lindgren <tony at atomide.com> wrote:
> >> > Hi,
> >> >
> >> > Looks like commit 5de85b9d57ab ("PM / runtime: Re-init runtime
> >> > PM states at probe error and driver unbind") broke PM on at least
> >> > omap3. It seems we now need to additionally also call
> >> > pm_runtime_dont_use_autosuspend() to get things working again?
> >> >
> >> > The following fixes idling on omap3, but I'm wondering if we
> >> > should do something in pm_runtime_reinit() instead?
> >>
> >> Well, does it actually help if you add
> >> pm_runtime_dont_use_autosuspend(dev) to pm_runtime_reinit()?
> >
> > No adding it to pm_runtime_reinit() does not help.
> 
> Yes, I realized that it wouldn't help only after sending the previous
> message, sorry about that.
>
> The reason why it helps in the driver code seems to be that
> autosuspend_delay happens to be negative, so update_autosuspend()
> decrements the usage counter that would have stayed incremented
> otherwise.  Or at least that's the only way it can help I see ATM.

Oh OK.

> > Looks like we have RPM_ACTIVE set in pm_runtime_reinit() if that
> > gives any clues.
> 
> It looks like pm_runtime_reinit() should clear the usage counter too.

Yeah if we do this when !pm_runtime_enabled(dev) it seems it's
safe to pretty much reset everything?

Regards,

Tony