tty: Improve reselience to rendering errors

src/tty.rs

@@ -33,6 +33,7 @@ use smithay_drm_extras::edid::EdidInfo;
 use crate::backend::Backend;
 use crate::{LoopData, Niri};
 
+const BACKGROUND_COLOR: [f32; 4] = [0.1, 0.1, 0.1, 1.];
 const SUPPORTED_COLOR_FORMATS: &[Fourcc] = &[Fourcc::Argb8888, Fourcc::Abgr8888];
 
 pub struct Tty {
@@ -68,18 +69,31 @@ impl Backend for Tty {
         elements: &[SpaceRenderElements<GlesRenderer, WaylandSurfaceRenderElement<GlesRenderer>>],
     ) {
         let output_device = self.output_device.as_mut().unwrap();
-        let res = output_device
+        let drm_compositor = &mut output_device.drm_compositor;
-            .drm_compositor
+
-            .render_frame::<_, _, GlesRenderbuffer>(
+        match drm_compositor.render_frame::<_, _, GlesRenderbuffer>(
             &mut output_device.gles,
             elements,
-                [0.1, 0.1, 0.1, 1.],
+            BACKGROUND_COLOR,
-            )
+        ) {
-            .unwrap();
+            Ok(res) => {
                 assert!(!res.needs_sync());
                 if res.damage.is_some() {
-            output_device.drm_compositor.queue_frame(()).unwrap();
+                    match output_device.drm_compositor.queue_frame(()) {
-        } else {
+                        Ok(()) => return,
+                        Err(err) => {
+                            error!("error queueing frame: {err}");
+                        }
+                    }
+                }
+            }
+            Err(err) => {
+                // Can fail if we switched to a different TTY.
+                error!("error rendering frame: {err}");
+            }
+        }
+
+        // FIXME: render on demand instead of busy looping.
         niri.event_loop
             .insert_source(
                 Timer::from_duration(Duration::from_millis(6)),
@@ -91,7 +105,6 @@ impl Backend for Tty {
             .unwrap();
     }
 }
-}
 
 impl Tty {
     pub fn new(event_loop: LoopHandle<LoopData>) -> Self {