Re: [PATCH] drm/i915/rc6: Disable RPG during workload execution

[Rodrigo Vivi <rodrigo.vivi@intel.com>]

On Thu, Oct 24, 2024 at 10:28:38AM -0400, Gupta, Anshuman wrote:
> 
> 
> > -----Original Message-----
> > From: Nilawar, Badal <badal.nilawar@intel.com>
> > Sent: Wednesday, October 23, 2024 9:42 PM
> > To: Vivi, Rodrigo <rodrigo.vivi@intel.com>
> > Cc: Andi Shyti <andi.shyti@linux.intel.com>; intel-gfx@lists.freedesktop.org;
> > Gupta, Anshuman <anshuman.gupta@intel.com>;
> > chris.p.wilson@linux.intel.com
> > Subject: Re: [PATCH] drm/i915/rc6: Disable RPG during workload execution
> > 
> > 
> > 
> > On 23-10-2024 21:31, Nilawar, Badal wrote:
> > >
> > >
> > > On 23-10-2024 20:18, Rodrigo Vivi wrote:
> > >> On Wed, Oct 23, 2024 at 11:03:57AM +0530, Nilawar, Badal wrote:
> > >>>
> > >>>
> > >>> On 22-10-2024 22:39, Rodrigo Vivi wrote:
> > >>>> On Tue, Oct 22, 2024 at 03:28:43PM +0200, Andi Shyti wrote:
> > >>>>> Hi Badal,
> > >>>>>
> > >>>>> On Tue, Oct 22, 2024 at 06:52:26PM +0530, Badal Nilawar wrote:
> > >>>>>> Encountering forcewake errors related to render power gating;
> > >>>>>
> > >>>>> Can you please expand your explanation here?
> > >>>>
> > >>>> yeap. More explanation please. All platforms? really?
> > >>>
> > >>> We are seeing Render forcewake timeouts on ADLP, ADLM, ADLN, TWL,
> > >>> DG1, rpl.
> > >>
> > >> Is this a regression? or a new issue?
> > >
> > > This is old issue, first reported year back.
> > >
> > >>
> > >> Is this happening with Xe on these platforms? or i915 only?
> > >
> > > i915 only. This is not reported on Xe kmd.
> > >
> > >>
> > >>> Issue disappears after disabling RPG. Instead of fully disabling RPG
> > >>> I am disabling it during active submissions i.e. during unpark.
> > >>> For MTL and ARL RPG is already disabled permanently.
> IMO this patch should be extended for MTL and ARL as well.
> Don't disable the RPG completely, only disable it during workload submission.
> That should save power on both MTL and ARL platforms, and right thing to do.
> And patch should add the Fixes tag accordingly to the commit which disables the RPG on MTL.
> @Vivi, Rodrigo what is your opinion on above ? it seems both MTL and ADL issues are same signature.
> MTL issue got disappear as RPG is disabled globally but that will burn power.
> If window does not have this issue then it is always difficult to get proper SV support.  
> But OS like window may not catch these kind of issues as they don't reload the their graphics driver like
> Linux reload module multiple times during selftest execution. Even chrome-os does not do that.
> Not a real world use case.

So we should change the tests without impacting the real world use case.

Let's try to grab the forcewake_all when using these self-tests, except the rc6 one.

> Thanks,
> Anshuman.
> > >>
> > >> uhm. Interesting. Why that is disabled on these platforms?
> > >
> > >  From commit log its temporary wa to avoid fw timeouts.
> > >
> > > perhaps we should be
> > >> doing the same for all GuC enabled platforms?
> > >
> > > I think so as temporary Wa.
> > 
> > Correction, DG1 we are not seeing this. I think we can go with platform check.
> > 
> > Regards,
> > Badal
>