This is a note to let you know that I've just added the patch titled
drm/i915: Flush outstanding requests before allocating new seqno
to the 3.10-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-flush-outstanding-requests-before-allocating-new-seqno.patch
and it can be found in the queue-3.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 304d695c3dc8eb65206b9eaf16f8d1a41510d1cf Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Date: Thu, 2 Jan 2014 14:32:35 +0000
Subject: drm/i915: Flush outstanding requests before allocating new seqno
From: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
commit 304d695c3dc8eb65206b9eaf16f8d1a41510d1cf upstream.
In very rare cases (such as a memory failure stress test) it is possible
to fill the entire ring without emitting a request. Under this
circumstance, the outstanding request is flushed and waited upon. After
space on the ring is cleared, we return to emitting the new command -
except that we just cleared the seqno allocated for this operation and
trigger the sanity check that a request is only ever emitted with a
valid seqno. The fix is to rearrange the code to make sure the
allocation of the seqno for this operation is after any required flushes
of outstanding operations.
The bug exists since the preallocation was introduced in
commit 9d7730914f4cd496e356acfab95b41075aa8eae8
Author: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Date: Tue Nov 27 16:22:52 2012 +0000
drm/i915: Preallocate next seqno before touching the ring
Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Cc: Mika Kuoppala <mika.kuoppala@xxxxxxxxx>
Cc: Daniel Vetter <daniel.vetter@xxxxxxxx>
Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Jani Nikula <jani.nikula@xxxxxxxxx>
Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/intel_ringbuffer.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -1459,8 +1459,8 @@ intel_ring_alloc_seqno(struct intel_ring
return i915_gem_get_seqno(ring->dev, &ring->outstanding_lazy_request);
}
-static int __intel_ring_begin(struct intel_ring_buffer *ring,
- int bytes)
+static int __intel_ring_prepare(struct intel_ring_buffer *ring,
+ int bytes)
{
int ret;
@@ -1476,7 +1476,6 @@ static int __intel_ring_begin(struct int
return ret;
}
- ring->space -= bytes;
return 0;
}
@@ -1491,12 +1490,17 @@ int intel_ring_begin(struct intel_ring_b
if (ret)
return ret;
+ ret = __intel_ring_prepare(ring, num_dwords * sizeof(uint32_t));
+ if (ret)
+ return ret;
+
/* Preallocate the olr before touching the ring */
ret = intel_ring_alloc_seqno(ring);
if (ret)
return ret;
- return __intel_ring_begin(ring, num_dwords * sizeof(uint32_t));
+ ring->space -= num_dwords * sizeof(uint32_t);
+ return 0;
}
void intel_ring_init_seqno(struct intel_ring_buffer *ring, u32 seqno)
Patches currently in stable-queue which might be from chris@xxxxxxxxxxxxxxxxxx are
queue-3.10/drm-i915-flush-outstanding-requests-before-allocating-new-seqno.patch
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