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>
This commit is contained in:
Francisco Jerez 2010-12-08 02:35:45 +01:00
parent a8b214f007
commit 937c3471cc

View file

@ -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);
/* 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;
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;