drm/i915/bdw: Force all Data Cache Data Port access to be Non-Coherent
I stumbled on to some unimplemented errata. To be honest, I am not
really sure of the impact, just that the docs say to do.
No w/a name for this one.
v2: v1 was a stale thing which should have never seen the light of day.
(Haihao)
Cc: Kenneth Graunke <kenneth@whitecape.org>
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
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 c68abf7..791fbe3 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -5269,6 +5269,14 @@
I915_READ(CHICKEN_PIPESL_1(i) |
DPRS_MASK_VBLANK_SRD));
}
+
+ /* Use Force Non-Coherent whenever executing a 3D context. This is a
+ * workaround for for a possible hang in the unlikely event a TLB
+ * invalidation occurs during a PSD flush.
+ */
+ I915_WRITE(HDC_CHICKEN0,
+ I915_READ(HDC_CHICKEN0) |
+ _MASKED_BIT_ENABLE(HDC_FORCE_NON_COHERENT));
}
static void haswell_init_clock_gating(struct drm_device *dev)