From 3ba6462355c1c69dde58739a871d13bbb993e2e3 Mon Sep 17 00:00:00 2001 From: Francisco Jerez Date: Sat, 28 Aug 2010 17:56:33 +0200 Subject: [PATCH] drm/nouveau: Take fence spinlock before reading the last sequence. It fixes a race between the TTM delayed work queue and the GEM IOCTLs (fdo bug 29583) uncovered by the BKL removal. Signed-off-by: Francisco Jerez Signed-off-by: Ben Skeggs --- drivers/gpu/drm/nouveau/nouveau_fence.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/nouveau/nouveau_fence.c b/drivers/gpu/drm/nouveau/nouveau_fence.c index 6b208ffafa8de..87ac21ec23d29 100644 --- a/drivers/gpu/drm/nouveau/nouveau_fence.c +++ b/drivers/gpu/drm/nouveau/nouveau_fence.c @@ -64,16 +64,17 @@ nouveau_fence_update(struct nouveau_channel *chan) struct nouveau_fence *fence; uint32_t sequence; + spin_lock(&chan->fence.lock); + if (USE_REFCNT) sequence = nvchan_rd32(chan, 0x48); else sequence = atomic_read(&chan->fence.last_sequence_irq); if (chan->fence.sequence_ack == sequence) - return; + goto out; chan->fence.sequence_ack = sequence; - spin_lock(&chan->fence.lock); list_for_each_safe(entry, tmp, &chan->fence.pending) { fence = list_entry(entry, struct nouveau_fence, entry); @@ -85,6 +86,7 @@ nouveau_fence_update(struct nouveau_channel *chan) if (sequence == chan->fence.sequence_ack) break; } +out: spin_unlock(&chan->fence.lock); }