[Intel-gfx] Graphical corruption post 2.6.38
chris at chris-wilson.co.uk
Wed Mar 23 15:08:24 CET 2011
On Wed, 23 Mar 2011 13:54:11 +0000, Colin Guthrie <intel at colin.guthr.ie> wrote:
> Running latest drivers from git + recent drm+xserver.
> After upgrading to 2.6.38 I seem to get occasional graphical corruption.
> This manifests itself mostly obviously in e.g gnome-terminal when
> getting git status and such like (although there are many other triggers
> - have seen it in various apps).
> Here is an example of what it looks like, but it can be much worse.
> Any idea of what could cause this before I go digging too deeply?
Author: Chris Wilson <chris at chris-wilson.co.uk>
Date: Thu Mar 17 15:23:22 2011 +0000
drm/i915: Fix tiling corruption from pipelined fencing
... even though it was disabled. A mistake in the handling of fence reuse
caused us to skip the vital delay of waiting for the object to finish
rendering before changing the register. This resulted in us changing the
fence register whilst the bo was active and so causing the blits to
complete using the wrong stride or even the wrong tiling. (Visually the
effect is that small blocks of the screen look like they have been
interlaced). The fix is to wait for the GPU to finish using the memory
region pointed to by the fence before changing it.
Cc: Andy Whitcroft <apw at canonical.com>
Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>
[Note for 2.6.38-stable, we need to reintroduce the interruptible passing]
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Tested-by: Dave Airlie <airlied at linux.ie>
Chris Wilson, Intel Open Source Technology Centre
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