[PATCH 13/17] drm/i915: Align tiled scanouts from stolen memory to 256k in the GTT

Rodrigo Vivi
2013-08-26T22:51:45Z

From: Chris Wilson <chris@chris-wilson.co.uk>

For unfathomable reasons this alignment appears to be required for tiled
scanouts being read from stolen memory. I can find no reference in the
w/a db to support this requirement, but the evidence of my own eyes says
this prevents many headaches.

Note that I have not tricked anything older than Sandybridge into using
stolen tiled scanouts, so the extra alignment may be required there as
well.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
---
drivers/gpu/drm/i915/intel_display.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 0da0ead1..cee9c0d 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -1837,6 +1837,8 @@ intel_pin_and_fence_fb_obj(struct drm_device *dev,
case I915_TILING_X:
/* pin() will align the object as required by fence */
alignment = 0;
+ if (obj->stolen && INTEL_INFO(dev)->gen >= 6)
+ alignment = 256 * 1024;
break;
case I915_TILING_Y:
/* Despite that we check this in framebuffer_init userspace can
--
1.8.1.4