[PATCH v4] ARM: perf: save/restore pmu registers in pm notifier

[Neil Zhang]

Sudeep & Will，

> -----Original Message-----
> From: Neil Zhang
> Sent: 2014年5月21日 19:47
> To: 'Sudeep Holla'; Will Deacon
> Cc: 'linux at arm.linux.org.uk'; 'linux-arm-kernel at lists.infradead.org';
> 'linux-kernel at vger.kernel.org'; 'devicetree at vger.kernel.org'
> Subject: RE: [PATCH v4] ARM: perf: save/restore pmu registers in pm notifier
> 
> Sudeep，
> 
> > -----Original Message-----
> > From: Sudeep Holla [mailto:sudeep.holla at arm.com]
> > Sent: 2014年5月14日 17:32
> > To: Neil Zhang; Will Deacon
> > Cc: Sudeep Holla; 'linux at arm.linux.org.uk';
> > 'linux-arm-kernel at lists.infradead.org';
> > 'linux-kernel at vger.kernel.org'; 'devicetree at vger.kernel.org'
> > Subject: Re: [PATCH v4] ARM: perf: save/restore pmu registers in pm
> > notifier
> >
> >
> >
> > On 14/05/14 03:28, Neil Zhang wrote:
> > >> -----Original Message-----
> > >> From: Will Deacon [mailto:will.deacon at arm.com]
> > >> Sent: 2014年5月14日 2:45
> > >> To: Neil Zhang
> > >> Cc: Sudeep Holla; 'linux at arm.linux.org.uk';
> > >> 'linux-arm-kernel at lists.infradead.org';
> > >> 'linux-kernel at vger.kernel.org'; 'devicetree at vger.kernel.org'
> > >> Subject: Re: [PATCH v4] ARM: perf: save/restore pmu registers in pm
> > >> notifier
> > >>
> > >> On Mon, May 12, 2014 at 11:22:09AM +0100, Neil Zhang wrote:
> > >>>>> The device tree bindings for power domains is under discussion
> > >>>>> [1]
> > >>>>
> > >>>> Thanks for the information.
> > >>>> But it currently for device only, core related stuff are not supported.
> > >>>> And is it really good to register power provider for core and let
> > >>>> vfp / pmu etc to get it?
> > >>>>
> > >>>
> > >>> What's your suggestion about it?
> > >>> Is it OK that I add it under the PMU node?
> > >>
> > >> I don't really mind. I just want to avoid re-inventing the wheel in
> > >> a PMU-specific way and having to maintain that code forever because
> > >> it ended up in our DT description.
> > >>
> > >> Will
> > >
> > > I will prepare another patch to add DT description under PMU since
> > > there is no generic power domain support for pm notifier if no other
> > concerns.
> > > We can change the manner if there is generic power domain support
> > > for
> > pm notifier later.
> > > Thanks.
> >
> > No, please don't add any DT bindings for power domains specific to PMU
> > node.
> > We can't change the DT bindings once added.
> >
> > As I pointed out the DT bindings for generic power domains are under
> > discussion.
> > See if you can reuse it, if not help in extending it so that it can be used.
> >
> 
> Sorry for reply later.
> As I said before the under discussed generic power domain is not suitable for
> CPU peripherals since they are all known belong to CPU or cluster power
> domain.
> If we want to follow the way they are discussion, we need to register core
> and cluster power provider, and need vfp/gic/pmu etc to require them.
> Is it really suitable?
> 
Do you have any comments?
If no, I would like to put it under PMU node.

> > Regards,
> > Sudeep
> >
> >
> 
> Best Regards,
> Neil Zhang

Best Regards,
Neil Zhang