[Intel-gfx] [PATCH] drm/i915: Only clear the GPU domains upon a successful finish

[Eugeni Dodonov]

On Tue, Nov 29, 2011 at 13:12, Chris Wilson <chris at chris-wilson.co.uk>wrote:

> By clearing the GPU read domains before waiting upon the buffer, we run
> the risk of the wait being interrupted and the domains prematurely
> cleared. The next time we attempt to wait upon the buffer (after
> userspace handles the signal), we believe that the buffer is idle and so
> skip the wait.
>
> There are a number of bugs across all generations which show signs of an
> overly haste reuse of active buffers.
>
> Such as:
>
>  https://bugs.freedesktop.org/show_bug.cgi?id=29046
>  https://bugs.freedesktop.org/show_bug.cgi?id=35863
>  https://bugs.freedesktop.org/show_bug.cgi?id=38952
>  https://bugs.freedesktop.org/show_bug.cgi?id=40282
>  https://bugs.freedesktop.org/show_bug.cgi?id=41098
>  https://bugs.freedesktop.org/show_bug.cgi?id=41102
>  https://bugs.freedesktop.org/show_bug.cgi?id=41284
>  https://bugs.freedesktop.org/show_bug.cgi?id=42141
>
> A couple of those pre-date i915_gem_object_finish_gpu(), so may be
> unrelated (such as a wild write from a userspace command buffer), but
> this does look like a convincing cause for most of those bugs.
>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: stable at kernel.org
>

Reviewed-by: Eugeni Dodonov <eugeni.dodonov at intel.com>

-- 
Eugeni Dodonov
<http://eugeni.dodonov.net/>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.freedesktop.org/archives/intel-gfx/attachments/20111129/f75f82fe/attachment.html>