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authorFrancisco Jerez <currojerez@riseup.net>2010-12-08 02:35:45 +0100
committerFrancisco Jerez <currojerez@riseup.net>2010-12-08 03:01:02 +0100
commit937c3471cc8b7ef8f9e382d9e4ec232db151ea7b (patch)
treec23158acf5103cab3306206fdb7839712e6201d9 /drivers/gpu/drm/nouveau/nouveau_fence.c
parenta8b214f007e299225d3fcf10c46f7fc603c275fa (diff)
drm/nouveau: Avoid potential race between nouveau_fence_update() and context takedown.
Signed-off-by: Francisco Jerez <currojerez@riseup.net> Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Diffstat (limited to 'drivers/gpu/drm/nouveau/nouveau_fence.c')
-rw-r--r--drivers/gpu/drm/nouveau/nouveau_fence.c19
1 files changed, 11 insertions, 8 deletions
diff --git a/drivers/gpu/drm/nouveau/nouveau_fence.c b/drivers/gpu/drm/nouveau/nouveau_fence.c
index 01290d2952ae..374a9793b85f 100644
--- a/drivers/gpu/drm/nouveau/nouveau_fence.c
+++ b/drivers/gpu/drm/nouveau/nouveau_fence.c
@@ -77,14 +77,17 @@ nouveau_fence_update(struct nouveau_channel *chan)
spin_lock(&chan->fence.lock);
- if (USE_REFCNT(dev))
- sequence = nvchan_rd32(chan, 0x48);
- else
- sequence = atomic_read(&chan->fence.last_sequence_irq);
-
- if (chan->fence.sequence_ack == sequence)
- goto out;
- chan->fence.sequence_ack = sequence;
+ /* Fetch the last sequence if the channel is still up and running */
+ if (likely(!list_empty(&chan->fence.pending))) {
+ if (USE_REFCNT(dev))
+ sequence = nvchan_rd32(chan, 0x48);
+ else
+ sequence = atomic_read(&chan->fence.last_sequence_irq);
+
+ if (chan->fence.sequence_ack == sequence)
+ goto out;
+ chan->fence.sequence_ack = sequence;
+ }
list_for_each_entry_safe(fence, tmp, &chan->fence.pending, entry) {
sequence = fence->sequence;