On Mon Jun 22, 2026 at 2:17 PM CEST, Christian König wrote: > Maybe an idea how to generally tackle this for all drivers: Never let the > dma-fence framework call dma_fence_signal(), that should only the driver do by > itself. > > This way we don't run into the issue in the first place that the driver needs > to install some callbacks *and* the driver also knows when the installed > callbacks are finished because that is when dma_fence_signal() returns. > > Does that sound valid to you guys? If yes I will be sending out patches to do > this.
I think that's a good idea, as it would get us rid of having to rely on API internals to synchronize struct dma_fence_cb callbacks without doing the full RCU dance, which can be quite cumbersome (as described in the nouveau case). It still leaves us with the full RCU dance for struct dma_fence_ops callbacks, but that's a different topic. Thanks, Danilo
