On Wed, 2025-04-09 at 14:51 +0200, Philipp Stanner wrote: > On Wed, 2025-04-09 at 14:39 +0200, Boris Brezillon wrote: > > Hi Philipp, > > > > On Wed, 9 Apr 2025 14:06:37 +0200 > > Philipp Stanner <pha...@kernel.org> wrote: > > > > > dma_fence_is_signaled()'s name strongly reads as if this function > > > were > > > intended for checking whether a fence is already signaled. Also > > > the > > > boolean it returns hints at that. > > > > > > The function's behavior, however, is more complex: it can check > > > with a > > > driver callback whether the hardware's sequence number indicates > > > that > > > the fence can already be treated as signaled, although the > > > hardware's / > > > driver's interrupt handler has not signaled it yet. If that's the > > > case, > > > the function also signals the fence. > > > > > > (Presumably) this has caused a bug in Nouveau (unknown commit), > > > where > > > nouveau_fence_done() uses the function to check a fence, which > > > causes a > > > race. > > > > > > Give the function a more obvious name. > > > > This is just my personal view on this, but I find the new name just > > as > > confusing as the old one. It sounds like something is checked, but > > it's > > clear what, and then the fence is forcibly signaled like it would > > be > > if > > you call drm_fence_signal(). Of course, this clarified by the doc, > > but > > given the goal was to make the function name clearly reflect what > > it > > does, I'm not convinced it's significantly better. > > > > Maybe dma_fence_check_hw_state_and_propagate(), though it might be > > too long of name. Oh well, feel free to ignore this comments if a > > majority is fine with the new name. > > Yoa, the name isn't perfect (the perfect name describing the whole > behavior would be > dma_fence_check_if_already_signaled_then_check_hardware_state_and_pro > pa > gate() ^^' > > My intention here is to have the reader realize "watch out, the fence > might get signaled here!", which is probably the most important event > regarding fences, which can race, invoke the callbacks and so on. > > For details readers will then check the documentation. > > But I'm of course open to see if there's a majority for this or that > name.
how about: dma_fence_check_hw_and_signal() ? P. > > P. > > > > > > Regards, > > > > Boris >
