[Intel-gfx] [PATCH] drm/i915/renderstate: Sandybridge golden renderstate is b0rked

[Chris Wilson]

In the null state batch, we try to load the CC_STATE_POINTERS, but pass
in a pointer to invalid state for the color-calc and depth-stencil
state. In the rendercopy batch this was imported from, the 1024 offset
used is known to be 64bytes of zeroes. Tweaking the
gen6_null_state_batch to point those two offset at known zeroes however
was not sufficient.

The effect of loading depth-stencil and color-calc causes the golden
renderstate batch to take 10s (yes, ten seconds) on my snb gt1 (i5-2500).

It would be nice if we could drop this incomplete "golden render state"
entirely.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala at linux.intel.com>
---
 drivers/gpu/drm/i915/intel_renderstate_gen6.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_renderstate_gen6.c b/drivers/gpu/drm/i915/intel_renderstate_gen6.c
index 11c8e7b3dd7c..46cfc405ca30 100644
--- a/drivers/gpu/drm/i915/intel_renderstate_gen6.c
+++ b/drivers/gpu/drm/i915/intel_renderstate_gen6.c
@@ -107,8 +107,8 @@ static const u32 gen6_null_state_batch[] = {
 	0x00000000,
 	0x780e0002,
 	0x00000441,
-	0x00000401,
-	0x00000401,
+	0x00000400,
+	0x00000400,
 	0x78021002,
 	0x00000000,
 	0x00000000,
-- 
2.13.3