[Beignet] [PATCH] drm/i915: Remove WaDisableLSQCROPERFforOCL KBL workaround.

[Greg KH]

On Tue, Jan 31, 2017 at 06:11:25AM +0100, Greg KH wrote:
> On Mon, Jan 30, 2017 at 12:24:45PM -0800, Francisco Jerez wrote:
> > The WaDisableLSQCROPERFforOCL workaround has the side effect of
> > disabling an L3SQ optimization that has huge performance implications
> > and is unlikely to be necessary for the correct functioning of usual
> > graphic workloads.  Userspace is free to re-enable the workaround on
> > demand, and is generally in a better position to determine whether the
> > workaround is necessary than the DRM is (e.g. only during the
> > execution of compute kernels that rely on both L3 fences and HDC R/W
> > requests).
> > 
> > The same workaround seems to apply to BDW (at least to production
> > stepping G1) and SKL as well (the internal workaround database claims
> > that it does for all steppings, while the BSpec workaround table only
> > mentions pre-production steppings), but the DRM doesn't do anything
> > beyond whitelisting the L3SQCREG4 register so userspace can enable it
> > when it sees fit.  Do the same on KBL platforms.
> > 
> > Improves performance of the GFXBench4 gl_manhattan31 benchmark by 60%,
> > and gl_4 (AKA car chase) by 14% on a KBL GT2 running Mesa master --
> > This is followed by a regression of 35% and 10% respectively for the
> > same benchmarks and platform caused by my recent patch series
> > switching userspace to use the dataport constant cache instead of the
> > sampler to implement uniform pull constant loads, which caused us to
> > hit more heavily the L3 cache (and on platforms other than KBL had the
> > opposite effect of improving performance of the same two benchmarks).
> > The overall effect on KBL of this change combined with the recent
> > userspace change is respectively 4.6% and 2.6%.  SynMark2 OglShMapPcf
> > was affected by the constant cache changes (though it improved as it
> > did on other platforms rather than regressing), but is not
> > significantly affected by this patch (with statistical significance of
> > 5% and sample size 20).
> > 
> > v2: Drop some more code to avoid unused variable warning.
> > 
> > Fixes: 738fa1b3123f ("drm/i915/kbl: Add WaDisableLSQCROPERFforOCL")
> > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=99256
> > Signed-off-by: Francisco Jerez <currojerez at riseup.net>
> > Cc: Matthew Auld <matthew.william.auld at gmail.com>
> > Cc: Eero Tamminen <eero.t.tamminen at intel.com>
> > Cc: Jani Nikula <jani.nikula at intel.com>
> > Cc: Mika Kuoppala <mika.kuoppala at intel.com>
> > Cc: beignet at lists.freedesktop.org
> > Cc: <stable at vger.kernel.org> # v4.7+
> > Reviewed-by: Mika Kuoppala <mika.kuoppala at intel.com>
> > [Removed double Fixes tag]
> > Signed-off-by: Mika Kuoppala <mika.kuoppala at intel.com>
> > Link: http://patchwork.freedesktop.org/patch/msgid/1484217894-20505-1-git-send-email-mika.kuoppala@intel.com
> > (cherry picked from commit 8726f2faa371514fba2f594d799db95203dfeee0)
> > Signed-off-by: Jani Nikula <jani.nikula at intel.com>
> > [ Francisco Jerez: Rebase on v4.9 branch. ]
> > Signed-off-by: Francisco Jerez <currojerez at riseup.net>
> > ---
> >  drivers/gpu/drm/i915/intel_lrc.c        | 3 +--
> >  drivers/gpu/drm/i915/intel_ringbuffer.c | 8 --------
> >  2 files changed, 1 insertion(+), 10 deletions(-)
> 
> What is the commit id of this patch in Linus's tree?

Ah, nevermind, it's 4fc020d864647ea3ae8cb8f17d63e48e87ebd0bf, right?

thanks,

greg k-h