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

[Ulf Hansson]

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.

Or, you or Tony intend to send a patch?

Kind regards
Uffe