From: Chris Wilson Date: Thu, 4 Apr 2013 20:31:03 +0000 (+0100) Subject: drm/i915: Workaround incoherence between fences and LLC across multiple CPUs X-Git-Tag: omap-for-v3.10/dt-fixes-for-merge-window~55^2~40^2~44 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=25ff1195f8a0b3724541ae7bbe331b4296de9c06;p=pandora-kernel.git drm/i915: Workaround incoherence between fences and LLC across multiple CPUs In order to fully serialize access to the fenced region and the update to the fence register we need to take extreme measures on SNB+, and manually flush writes to memory prior to writing the fence register in conjunction with the memory barriers placed around the register write. Fixes i-g-t/gem_fence_thrash v2: Bring a bigger gun v3: Switch the bigger gun for heavier bullets (Arjan van de Ven) v4: Remove changes for working generations. v5: Reduce to a per-cpu wbinvd() call prior to updating the fences. v6: Rewrite comments to ellide forgotten history. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=62191 Signed-off-by: Chris Wilson Cc: Jon Bloomfield Tested-by: Jon Bloomfield (v2) Cc: stable@vger.kernel.org Reviewed-by: Jesse Barnes Signed-off-by: Daniel Vetter --- Reading git-diff-tree failed