Hi Lyude
> On 30 Sep 2024, at 20:09, Lyude Paul <lyude@xxxxxxxxxx> wrote:
>
> This adds a simple binding for completing the last step of creating a DRM
> connector - attaching its encoder. This function should only be called
> before the connector is registered, and DRM should enforce this itself by
> returning an error if a driver tries to add an encoder to an
> already-registered DRM connector.
>
> Note that unlike most of the methods we'll be adding to DRM mode objects,
> this is directly implemented on the Connector<T> type since I don't really
> think it would make sense for us to allow this operation on an
> OpaqueConnector (a DRM connector without a known DriverConnector
> implementation, something we'll be adding in the next few commits).
>
> Signed-off-by: Lyude Paul <lyude@xxxxxxxxxx>
>
> ---
>
> TODO:
> * Figure out a solution for making sure that this can only be called when a
> Connector is unregistered, probably via an UnregisteredConnector type.
>
Either that, or via the typestate pattern. But I think a UnregisteredConnector type
will work fine based on your previous UnregisteredKmsDevice.
> Signed-off-by: Lyude Paul <lyude@xxxxxxxxxx>
> ---
> rust/kernel/drm/kms/connector.rs | 15 +++++++++++++++
> 1 file changed, 15 insertions(+)
>
> diff --git a/rust/kernel/drm/kms/connector.rs b/rust/kernel/drm/kms/connector.rs
> index 0fa927a3743b2..54457b327c365 100644
> --- a/rust/kernel/drm/kms/connector.rs
> +++ b/rust/kernel/drm/kms/connector.rs
> @@ -28,6 +28,7 @@
> use super::{
> ModeObject,
> RcModeObject,
> + encoder::*,
> KmsDriver,
> };
> use macros::pin_data;
> @@ -227,6 +228,20 @@ pub fn new(
> ARef::from_raw(NonNull::new_unchecked(Box::into_raw(Pin::into_inner_unchecked(new))))
> })
> }
> +
> + /// Attach an encoder to this [`Connector`].
> + ///
> + /// TODO: Move this to an `UnregisteredConnector` interface somehow…
> + #[must_use]
> + pub fn attach_encoder<E>(&self, encoder: &Encoder<E>) -> Result
> + where
> + E: DriverEncoder<Driver = T::Driver>
> + {
> + // SAFETY: FFI call with no special requirements
> + to_result(unsafe {
> + bindings::drm_connector_attach_encoder(self.as_raw(), encoder.as_raw())
> + })
> + }
> }
>
> /// A trait implemented by any type that acts as a [`struct drm_connector`] interface.
> --
> 2.46.1
>
>
LGTM.
— Daniel
