Re: [PATCH] drm/i915: Disable WaGsvRC0ResidencyMethod for vlv

From: Jani Nikula <jani.nikula@linux.intel.com>
To: Daniel Vetter <daniel@ffwll.ch>,
	Deepak S <deepak.s@linux.intel.com>,
	intel-gfx@lists.freedesktop.org, daniel.vetter@ffwll.ch
Subject: Re: [PATCH] drm/i915: Disable WaGsvRC0ResidencyMethod for vlv
Date: Mon, 13 Apr 2015 15:06:45 +0300	[thread overview]
Message-ID: <87twwkp6zu.fsf@intel.com> (raw)
In-Reply-To: <20150319163804.GE31422@phenom.ffwll.local>

On Thu, 19 Mar 2015, Daniel Vetter <daniel@ffwll.ch> wrote:
> On Thu, Mar 19, 2015 at 03:38:19PM +0200, David Weinehall wrote:
>> On Thu, Mar 19, 2015 at 06:17:00PM +0530, Deepak S wrote:
>> > 
>> > 
>> > On Thursday 19 March 2015 05:14 PM, David Weinehall wrote:
>> > >On Thu, Mar 19, 2015 at 04:09:44PM +0530, deepak.s@linux.intel.com wrote:
>> > >>From: Deepak S <deepak.s@linux.intel.com>
>> > >>
>> > >>Unfortunately WaGsvRC0ResidencyMethod causing system freeze on some
>> > >>of the baytrail systems :(. Switching back to legacy mode rps.
>> > >Is there any way to identify either what systems it's OK to use on,
>> > >or to identif what Baytrail systems it isn't OK to use on?
>> > >
>> > >Just reverting this completely seems overly broad if it's possible to
>> > >tell the difference between working and non-working systems.
>> > 
>> > Restricting the changes to few system will be the right way to go.
>> > How do we get details of now working system?
>> 
>> That depends.  Who reported the non-working Baytrail-systems?
>> And just as importantly, do we have Baytrail systems where this is
>> confirmed to work?
>> 
>> If we can identify the respective revisions of the systems
>> we might be able to discern the pattern and continue from there.
>
> My experience with random crashes with rps on snb/ivb is that there's no
> solid systems, just systems where no one has bothered to be really evil
> yet.
>
> I'd be really cautious with whitelisting since it tends to not really
> solve the underlying bug (if there is one), usually blows up really fast
> in size and is long-term unmaintainable. We've been there a few times with
> other hacks and issues :(

Plenty of talk but no final verdict on the patch either way, and the bug
is still open too. :(

Deepak, is this patch still needed?

BR,
Jani.

> -Daniel
> -- 
> Daniel Vetter
> Software Engineer, Intel Corporation
> http://blog.ffwll.ch
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Jani Nikula, Intel Open Source Technology Center
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