drm/i915: Enable provoking vertex fix on Gen9 systems.
authorKenneth Graunke <kenneth@whitecape.org>
Fri, 15 Jun 2018 19:06:05 +0000 (20:06 +0100)
committerJani Nikula <jani.nikula@intel.com>
Tue, 19 Jun 2018 12:48:24 +0000 (15:48 +0300)
commit7a3727f385dc64773db1c144f6b15c1e9d4735bb
tree9f455b3dc5bae21e6e70322eec915aeb00e6036b
parentbc64e05408cafe3668e7460834935ea3f1764f31
drm/i915: Enable provoking vertex fix on Gen9 systems.

The SF and clipper units mishandle the provoking vertex in some cases,
which can cause misrendering with shaders that use flat shaded inputs.

There are chicken bits in 3D_CHICKEN3 (for SF) and FF_SLICE_CHICKEN
(for the clipper) that work around the issue.  These registers are
unfortunately not part of the logical context (even the power context),
and so we must reload them every time we start executing in a context.

Bugzilla: https://bugs.freedesktop.org/103047
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180615190605.16238-1-chris@chris-wilson.co.uk
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: stable@vger.kernel.org
(cherry picked from commit b77422f80337d363eed60c8c48db9cb6e33085c9)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
drivers/gpu/drm/i915/i915_reg.h
drivers/gpu/drm/i915/intel_lrc.c