This is a note to let you know that I've just added the patch titled
drm/i915: Only clear the GPU domains upon a successful finish
to the 3.3-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-i915-only-clear-the-gpu-domains-upon-a-successful-finish.patch
and it can be found in the queue-3.3 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From c501ae7f332cdaf42e31af30b72b4b66cbbb1604 Mon Sep 17 00:00:00 2001
From: Chris Wilson <[email protected]>
Date: Wed, 14 Dec 2011 13:57:23 +0100
Subject: drm/i915: Only clear the GPU domains upon a successful finish
From: Chris Wilson <[email protected]>
commit c501ae7f332cdaf42e31af30b72b4b66cbbb1604 upstream.
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 <[email protected]>
Reviewed-by: Daniel Vetter <[email protected]>
Reviewed-by: Eugeni Dodonov <[email protected]>
Signed-off-by: Daniel Vetter <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/gpu/drm/i915/i915_gem.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3084,10 +3084,13 @@ i915_gem_object_finish_gpu(struct drm_i9
return ret;
}
+ ret = i915_gem_object_wait_rendering(obj);
+ if (ret)
+ return ret;
+
/* Ensure that we invalidate the GPU's caches and TLBs. */
obj->base.read_domains &= ~I915_GEM_GPU_DOMAINS;
-
- return i915_gem_object_wait_rendering(obj);
+ return 0;
}
/**
Patches currently in stable-queue which might be from [email protected]
are
queue-3.3/drm-i915-only-clear-the-gpu-domains-upon-a-successful-finish.patch
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