On Mon, 2012-09-10 at 11:13 +0200, Christian König wrote:
Only increase the higher 32bits if we really detect a wrap around.
Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=54129 https://bugs.freedesktop.org/show_bug.cgi?id=54662
Possible fixes: https://bugzilla.redhat.com/show_bug.cgi?id=846505 https://bugzilla.redhat.com/show_bug.cgi?id=845639
Signed-off-by: Christian König deathsimple@vodafone.de Cc: stable@vger.kernel.org
drivers/gpu/drm/radeon/radeon_fence.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/radeon/radeon_fence.c b/drivers/gpu/drm/radeon/radeon_fence.c index 7b737b9..4781e13 100644 --- a/drivers/gpu/drm/radeon/radeon_fence.c +++ b/drivers/gpu/drm/radeon/radeon_fence.c @@ -160,7 +160,7 @@ void radeon_fence_process(struct radeon_device *rdev, int ring) do { seq = radeon_fence_read(rdev, ring); seq |= last_seq & 0xffffffff00000000LL;
if (seq < last_seq) {
if (seq < (last_seq - 0x80000000LL)) { seq += 0x100000000LL;
Can you provide a bit more explanation for this change? In particular, how could the code previously detect a wraparound when there was none, and why is this the proper fix?