Re: [PATCH 1/2] drm/tyr: add Wait type for GPU events

[Danilo Krummrich]

On Tue Jul 21, 2026 at 5:14 PM CEST, Laura Nao wrote:
> +/// A convenience type to wait for GPU events.
> +///
> +/// Wraps a [`CondVar`] and [`Mutex`] pair. The mutex synchronizes predicate checks
> +/// with wait/wake operations; the condvar provides the sleep/wake mechanism.
> +#[pin_data]
> +pub(crate) struct Wait {
> +    /// The actual wait/signal mechanism.
> +    #[pin]
> +    cond: CondVar,
> +    /// Synchronizes waiters with notifications.
> +    #[pin]
> +    lock: Mutex<()>,
> +}

This is backwards; if I get this right at a quick glance it is basically abusing
CondVar to implement a WaitQueue abstraction in your driver.

What you actually seem to look for is a proper WaitQueue abstraction, which
could then also be used to simplify the implementation of CondVar.

I'm already working on a WaitQueue abstraction, since I need it elsewhere. I can
probably post something in a few days.

(I didn't check your use-case but you may want to consider completions and
simple waitqueue as well.)