drm/i915/gen9: Add GEN8_CS_CHICKEN1 to HW whitelist
Required for WaEnablePreemptionGranularityControlByUMD:skl,bxt
This register is added to HW whitelist to support WA required for future
enabling of pre-emptive command execution, WA implementation will be in
userspace and it cannot program this register if it is not on HW whitelist.
v2: explain purpose of WA (Chris)
Reviewed-by: Nick Hoath <nicholas.hoath@intel.com>
Signed-off-by: Arun Siluvery <arun.siluvery@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1453412634-29238-3-git-send-email-arun.siluvery@linux.intel.com
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 43fa140..c938b93 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -910,6 +910,7 @@
struct drm_device *dev = ring->dev;
struct drm_i915_private *dev_priv = dev->dev_private;
uint32_t tmp;
+ int ret;
/* WaEnableLbsSlaRetryTimerDecrement:skl */
I915_WRITE(BDW_SCRATCH1, I915_READ(BDW_SCRATCH1) |
@@ -980,6 +981,11 @@
/* WaDisableSTUnitPowerOptimization:skl,bxt */
WA_SET_BIT_MASKED(HALF_SLICE_CHICKEN2, GEN8_ST_PO_DISABLE);
+ /* WaEnablePreemptionGranularityControlByUMD:skl,bxt */
+ ret= wa_ring_whitelist_reg(ring, GEN8_CS_CHICKEN1);
+ if (ret)
+ return ret;
+
return 0;
}