Re: [FOR DISCUSSION 0/9] Dove PMU support

[Russell King - ARM Linux <linux@arm.linux.org.uk>]

On Thu, Mar 19, 2015 at 11:02:35PM +0100, Rafael J. Wysocki wrote:
> On Thursday, March 19, 2015 10:59:20 PM Rafael J. Wysocki wrote:
> > On Thursday, March 12, 2015 06:30:21 PM Russell King - ARM Linux wrote:
> > > This is a re-posting of the patch set which I posted almost 10 months
> > > ago to support the Dove PMU, with a few additional changes.  This set
> > > is based upon 3.19.
> > > 
> > > In this set are:
> > > 
> > > * two patches which Rafael originally acked, but there was indecision
> > >   last time around how to handle them due to potential conflicts with
> > >   work that Ulf was doing.  These patches have been updated to apply
> > >   cleanly to 3.19.  I don't know if people want to take these as
> > >   fixes to the PM domain code or not (hence why I'm posting this
> > >   series during the merge window - if it weren't for this, I'd hold
> > >   it off.)
> > > 
> > > * what I regard as a fix to the PM domain code; as a result of a
> > >   previous commit, the PM domain code mismatches the runtime PM state,
> > >   which leads to the PM domain being unexpectedly left on.  This patch
> > >   has been re-worked to try an alternative approach, syncing the PM
> > >   domain state with the runtime PM state after the probe has completed.
> > > 
> > > * the addition of the core Dove PMU driver, which consists of a reset,
> > >   IRQ controller, and power domains.  The reset and power domain code
> > >   has to be closely related due to the power up/down requirements of
> > >   the GPU/VPU subsystems needing to be performed atomically.  (This
> > >   requirement prevents it using the MFD infrastructure, because we
> > >   would need to hold spinlocks while calling several different
> > >   sub-drivers.)
> > > 
> > > * addition of the RTC interrupt, so we can now receive and act on
> > >   alarms generated by the Dove RTC.
> > > 
> > > * addition of the DT descriptions for the GPU and VPU power domains.
> > >   These patches do not themselves add the DT descriptions for these
> > >   units, so these patches serve as illustrations how these should be
> > >   described.
> > > 
> > 
> > I can apply patches [1-3/9] from this series if that helps.
> 
> I mean from the next version of it ([FOR DISCUSSION 0/10] Dove PMU support).

Kevin had some comments on patch 2 which I think ought to be addressed.
He's quite right that dev_to_genpd() should be hidden from view and
replaced with the safer pm_genpd_lookup_dev() version - even though
pm_genpd_lookup_dev() itself is not fully safe against the domain
on a device changing beneath it.

If you want to hold on, I'll respin with his comments there addressed,
or if you prefer to merge them as-is and fix Kevin's comments afterwards,
that's also fine by me.

I'd just be happy to see some progress on this series. :)

Thanks.

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