drm/i915: Disable SF pipelined attribute fetch for SNB
According to Bspec we need to disable SF pipelined attribute fetch
whenever SF outputs exceed 16 and normal clip mode is used. A quick
glance at Mesa suggests that these conditions could happen. So let's
just always set the magic bit.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index f74d7f5..0ed4df2 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -4698,6 +4698,14 @@
_3D_CHICKEN3_SF_DISABLE_FASTCLIP_CULL);
/*
+ * Bspec says:
+ * "This bit must be set if 3DSTATE_CLIP clip mode is set to normal and
+ * 3DSTATE_SF number of SF output attributes is more than 16."
+ */
+ I915_WRITE(_3D_CHICKEN3,
+ _MASKED_BIT_ENABLE(_3D_CHICKEN3_SF_DISABLE_PIPELINED_ATTR_FETCH));
+
+ /*
* According to the spec the following bits should be
* set in order to enable memory self-refresh and fbc:
* The bit21 and bit22 of 0x42000