drm/i915/kbl: Add WaDisableGafsUnitClkGating
We need to disable clock gating in this unit to work around
hardware issue causing possible corruption/hang.
v2: name the bit (Ville)
v3: leave the fix enabled for 2227050 and set correct bit (Matthew)
v4: Split out the skl part in separate commit for easier backport
References: HSD#2227156, HSD#2227050
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Matthew Auld <matthew.william.auld@gmail.com>
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1465309159-30531-20-git-send-email-mika.kuoppala@intel.com
(cherry picked from commit 4de5d7ccbccc88d2f7b1bcdc2180196ded7db8b8)
Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index da9d243..a88ac27 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -1230,6 +1230,9 @@
WA_SET_BIT_MASKED(COMMON_SLICE_CHICKEN2,
GEN8_SBE_DISABLE_REPLAY_BUF_OPTIMIZATION);
+ /* WaDisableGafsUnitClkGating:kbl */
+ WA_SET_BIT(GEN7_UCGCTL4, GEN8_EU_GAUNIT_CLOCK_GATE_DISABLE);
+
/* WaDisableLSQCROPERFforOCL:kbl */
ret = wa_ring_whitelist_reg(engine, GEN8_L3SQCREG4);
if (ret)
