[2.6.35-rc regression] i915: cursor corruption on Arrandale caused by 9b8c4a0b215e

[2.6.35-rc regression] i915: cursor corruption on Arrandale caused by 9b8c4a0b215e

[Andy Isaacson]

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My x201s (Core i7 L640 according to /proc/cpuinfo) running -rc1 exhibits
cursor corruption when changing the cursor image (such as when moving
out of xterm onto the desktop).  Bisection pointed to 9b8c4a0b215e and
reverting that on top of 03cd373981 fixed the problem.  I'm running
fvwm2 with xterm as my primary X client; the driver is

xserver-xorg-video-intel             2:2.9.1-4

The corruption generally goes away within a second or two, and seems to
consist of the previous cursor image interleaved with the new cursor
image on a row-by-row basis.  Some kind of cache flush issue?

I've attached a JPG of a corrupted cursor.

-andy

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Re: [2.6.35-rc regression] i915: cursor corruption on Arrandale caused by 9b8c4a0b215e

[Chris Wilson]

On Sat, 5 Jun 2010 19:21:15 -0700, Andy Isaacson <adi@hexapodia.org> wrote:
> My x201s (Core i7 L640 according to /proc/cpuinfo) running -rc1 exhibits
> cursor corruption when changing the cursor image (such as when moving
> out of xterm onto the desktop).  Bisection pointed to 9b8c4a0b215e and
> reverting that on top of 03cd373981 fixed the problem.  I'm running
> fvwm2 with xterm as my primary X client; the driver is
> 
> xserver-xorg-video-intel             2:2.9.1-4
> 
> The corruption generally goes away within a second or two, and seems to
> consist of the previous cursor image interleaved with the new cursor
> image on a row-by-row basis.  Some kind of cache flush issue?

Exactly; a missing move-to-GTT-domain causing the cursor data to remain in
the CPU cache.

https://bugs.freedesktop.org/show_bug.cgi?id=28335

-- 
Chris Wilson, Intel Open Source Technology Centre