From 7a3727f385dc64773db1c144f6b15c1e9d4735bb Mon Sep 17 00:00:00 2001
From: Kenneth Graunke <kenneth@whitecape.org>
Date: Fri, 15 Jun 2018 20:06:05 +0100
Subject: [PATCH] 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 | 5 +++++
drivers/gpu/drm/i915/intel_lrc.c | 12 +++++++++++-
2 files changed, 16 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index f11bb213ec078..7720569f20244 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -2425,12 +2425,17 @@ enum i915_power_well_id {
#define _3D_CHICKEN _MMIO(0x2084)
#define _3D_CHICKEN_HIZ_PLANE_DISABLE_MSAA_4X_SNB (1 << 10)
#define _3D_CHICKEN2 _MMIO(0x208c)
+
+#define FF_SLICE_CHICKEN _MMIO(0x2088)
+#define FF_SLICE_CHICKEN_CL_PROVOKING_VERTEX_FIX (1 << 1)
+
/* Disables pipelining of read flushes past the SF-WIZ interface.
* Required on all Ironlake steppings according to the B-Spec, but the
* particular danger of not doing so is not specified.
*/
# define _3D_CHICKEN2_WM_READ_PIPELINED (1 << 14)
#define _3D_CHICKEN3 _MMIO(0x2090)
+#define _3D_CHICKEN_SF_PROVOKING_VERTEX_FIX (1 << 12)
#define _3D_CHICKEN_SF_DISABLE_OBJEND_CULL (1 << 10)
#define _3D_CHICKEN3_AA_LINE_QUALITY_FIX_ENABLE (1 << 5)
#define _3D_CHICKEN3_SF_DISABLE_FASTCLIP_CULL (1 << 5)
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index f3968580e5e22..7c4c8fb1dae46 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -1545,11 +1545,21 @@ static u32 *gen9_init_indirectctx_bb(struct intel_engine_cs *engine, u32 *batch)
/* WaFlushCoherentL3CacheLinesAtContextSwitch:skl,bxt,glk */
batch = gen8_emit_flush_coherentl3_wa(engine, batch);
+ *batch++ = MI_LOAD_REGISTER_IMM(3);
+
/* WaDisableGatherAtSetShaderCommonSlice:skl,bxt,kbl,glk */
- *batch++ = MI_LOAD_REGISTER_IMM(1);
*batch++ = i915_mmio_reg_offset(COMMON_SLICE_CHICKEN2);
*batch++ = _MASKED_BIT_DISABLE(
GEN9_DISABLE_GATHER_AT_SET_SHADER_COMMON_SLICE);
+
+ /* BSpec: 11391 */
+ *batch++ = i915_mmio_reg_offset(FF_SLICE_CHICKEN);
+ *batch++ = _MASKED_BIT_ENABLE(FF_SLICE_CHICKEN_CL_PROVOKING_VERTEX_FIX);
+
+ /* BSpec: 11299 */
+ *batch++ = i915_mmio_reg_offset(_3D_CHICKEN3);
+ *batch++ = _MASKED_BIT_ENABLE(_3D_CHICKEN_SF_PROVOKING_VERTEX_FIX);
+
*batch++ = MI_NOOP;
/* WaClearSlmSpaceAtContextSwitch:kbl */
--
2.30.2