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It wakes up every T milliseconds and > opportunistically asks through dma_fence_is_signaled() (and that > through ops->signaled() which fences are already signaled. That's a pretty good summary we should probably add it to the documentation. Just one additional note: The userspace deamon is usually the compositor who is in control of the CRTCs and the interrupt is the periodical refresh timer, usually vblank. Christian. > > P.