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

[Rafael J. Wysocki]

On Wednesday, January 27, 2016 09:17:45 AM Ulf Hansson wrote:
> On 27 January 2016 at 08:54, Rafael J. Wysocki <rjw at rjwysocki.net> wrote:
> > On Tuesday, January 26, 2016 03:52:23 PM Tony Lindgren wrote:
> >> * 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?
> >
> > Not only safe, but also a good idea apparently. :-)
> 
> I happy to send a patch, extending pm_runtime_reinit() with some more
> data to be reset.

Please do.

Thanks,
Rafael