Struct Modeset 

pub struct Modeset<'a> { /* private fields */ }

The CRTC and connector writes that bring a display up.

Plane properties alone do not light a screen. Until the CRTC has a mode and is ACTIVE, and some connector routes to it, a commit that binds planes to that CRTC is rejected – and the planes have nowhere to scan out to even if it were not. Upstream folds these writes into the first commit after create() or rebind() and ORs in ALLOW_MODESET to let them through; this is the same set.

Easy to leave out and not notice: most desktops run a DRM fbdev client that re-enables the CRTC as soon as the previous master drops it, so a scene that never writes these still commits successfully on a developer’s machine. It fails on a system that boots without one.

Implementations

impl<'a> Modeset<'a>

pub fn learn( device: &'a Device, crtc_id: u32, connector_id: u32, mode: &Mode, ) -> Result<Self, CoreError>

Resolve the three property ids and stage mode as a blob.

The blob is created once and reused for every commit: it describes the mode, which does not change while the scene is bound to this CRTC.

Errors

CoreError if a property is missing – every atomic driver exposes all three, so an absent one means this is not an atomic-capable device – or if the kernel refuses the blob.

pub fn emit(&self, request: &mut AtomicRequest) -> Result<usize, CoreError>

Emit the modeset writes. Returns how many properties were written.

Errors

CoreError if a property write is rejected before the commit.

pub const fn mode_blob(&self) -> u64

The blob id backing MODE_ID.