On Tue, 2026-06-16 at 13:02 +0200, Danilo Krummrich wrote:
> On Tue Jun 16, 2026 at 10:28 AM CEST, Philipp Stanner wrote:
> > Changes since v1:
>
> It seems that some of the comments from v1 [1][2] are not addressed, did you
> forget them?
yeah, a bunch of stuff might have slipped me. Mea culpa. Need to
address some more issues in v3 anyways; but wanted to present the rough
RCU idea here as a heads-up.
>
> In particular the pin_init_from_closure() looks unnecessary and can probably
> replaced with something like (untested):
>
> let mut callback = Some(callback);
>
> try_pin_init!(Self {
> cb <- Opaque::try_ffi_init(|ptr| {
> // SAFETY: `fence.inner.get()` is a valid, initialized `struct
> dma_fence`. `ptr`
> // points to the `struct dma_fence_cb` field within the pinned
> allocation, so it
> // remains valid until `dma_fence_remove_callback()` in
> `PinnedDrop` or until the
> // callback fires.
> let ret = unsafe {
> to_result(bindings::dma_fence_add_callback(
> fence.inner.get(),
> ptr,
> Some(Self::dma_fence_callback),
> ))
> };
> match ret {
> Ok(()) => Ok(()),
> Err(e) => {
> let cb_back = callback.take().expect("success path did
> not run");
> if e == ENOENT {
> Err(CallbackError::AlreadySignaled(cb_back))
> } else {
> Err(CallbackError::Other(e))
> }
> }
> }
> }),
> callback: callback.take().expect("error path did not run"),
> fence: ARef::from(fence),
> }? CallbackError<T>)
>
> Please also see my previous comments regarding DriverFenceBorrow, it still
> seems
> to miss the lifetime and it should probably use ManuallyDrop<DriverFence>.
ACK.
>
> It also seems the patch series was created without --base, what's the base
> revision?
Branched out from drm-misc-next for development purposes (since it
heavily relies on dma-fence.c)
I can rebase on drm-rust-next for the next revision.
>
> [1] https://lore.kernel.org/all/[email protected]/
> [2] https://lore.kernel.org/all/[email protected]/
