[PATCH 2/2] Correct BO allocation alignment

Keith Packard keithp at keithp.com
Wed Sep 10 14:09:09 PDT 2014


BO allocations for pixmaps must be aligned to the tile height, but at
some point the code was changed to align them to twice the tile
height. This overallocates pixmaps, wasting memory, but more
importantly, for buffers allocated by DRM and shared through DRI3, the
stricter alignment check causes sharing to fail.

>From reading through the history of the code and related bugs, it
seems like this change was part of a set of changes trying to address
what turned out to be a kernel regression. Reverting this change
solves the DRI3 problem and saves a bit of memory for pixmap
allocations.

Signed-off-by: Keith Packard <keithp at keithp.com>
---
 src/uxa/intel_uxa.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/uxa/intel_uxa.c b/src/uxa/intel_uxa.c
index d33eca5..4ce6eae 100644
--- a/src/uxa/intel_uxa.c
+++ b/src/uxa/intel_uxa.c
@@ -206,7 +206,7 @@ intel_uxa_compute_size(struct intel_screen_private *intel,
 			tile_height = 8;
 		else
 			tile_height = 32;
-		aligned_h = ALIGN(h, 2*tile_height);
+		aligned_h = ALIGN(h, tile_height);
 
 		*stride = intel_get_fence_pitch(intel,
 						ALIGN(pitch, 512),
@@ -768,7 +768,7 @@ free_priv:
 			else
 				height = 32;
 
-			height = ALIGN(pixmap->drawable.height, 2*height);
+			height = ALIGN(pixmap->drawable.height, height);
 			size = intel_get_fence_size(intel, priv->stride * height);
 		} else
 			size = priv->stride * pixmap->drawable.height;
-- 
2.0.1



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