From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Widawsky Subject: Re: [PATCH 2/2] drm/i915/skl: Fix spurious gpu hang with gt3/gt4 revs Date: Tue, 5 Apr 2016 08:44:48 -0700 Message-ID: <20160405154446.GA28348@intel.com> References: <1459860977-27751-1-git-send-email-mika.kuoppala@intel.com> <1459860977-27751-2-git-send-email-mika.kuoppala@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1459860977-27751-2-git-send-email-mika.kuoppala@intel.com> Sender: stable-owner@vger.kernel.org To: Mika Kuoppala Cc: intel-gfx@lists.freedesktop.org, Abdiel Janulgue , Timo Aaltonen , stable@vger.kernel.org List-Id: intel-gfx@lists.freedesktop.org On Tue, Apr 05, 2016 at 03:56:17PM +0300, Mika Kuoppala wrote: > Experiments with heaven 4.0 benchmark and skylake gt3e (rev 0xa) > suggest that WaForceContextSaveRestoreNonCoherent is needed for all > revs. Extending this to all revs cures a gpu hang with rev 0xa when > running heaven4.0 gpu benchmark. > > We have been here before, with problems enabling gt4e and extending > up to revision F0 instead of false claims of bspec of E0 only. See > commit ("drm/i915/skl: Default to noncoherent access > up to F0"). In retrospect we should have covered this with this big > blanket back then already, as E0 vs F0 discrepancy was suspicious > enough. > > Previously the WaForceEnableNonCoherent has been tied to > context non-coherence, atleast in relevant hsds. So keep this tie > and extended this alongside. > > Cc: Abdiel Janulgue > Cc: Ben Widawsky > Cc: Timo Aaltonen > Cc: stable@vger.kernel.org > Reported-by: Mike Lothian > References: https://bugs.freedesktop.org/show_bug.cgi?id=93491 > Signed-off-by: Mika Kuoppala I don't have a reproducible hang, but both are: Reviewed-by: Ben Widawsky -- Ben Widawsky, Intel Open Source Technology Center