Store gamma changes to apply on session resume

3 files changed, 32 insertions, 7 deletions

diff --git a/src/backend/tty.rs b/src/backend/tty.rs
index 4cc45b0c..e7b60900 100644
--- a/src/backend/tty.rs
+++ b/src/backend/tty.rs
@@ -169,6 +169,8 @@ struct Surface {
     compositor: GbmDrmCompositor,
     dmabuf_feedback: Option<SurfaceDmabufFeedback>,
     gamma_props: Option<GammaProps>,
+    /// Gamma change to apply upon session resume.
+    pending_gamma_change: Option<Option<Vec<u16>>>,
     /// Tracy frame that goes from vblank to vblank.
     vblank_frame: Option<tracy_client::Frame>,
     /// Frame name for the VBlank frame.
@@ -394,6 +396,22 @@ impl Tty {
 
                     // Refresh the connectors.
                     self.device_changed(node.dev_id(), niri);
+
+                    // Apply pending gamma changes.
+                    let device = self.devices.get_mut(&node).unwrap();
+                    for (crtc, surface) in device.surfaces.iter_mut() {
+                        if let Some(ramp) = surface.pending_gamma_change.take() {
+                            let ramp = ramp.as_deref();
+                            let res = if let Some(gamma_props) = &mut surface.gamma_props {
+                                gamma_props.set_gamma(&device.drm, ramp)
+                            } else {
+                                set_gamma_for_crtc(&device.drm, *crtc, ramp)
+                            };
+                            if let Err(err) = res {
+                                warn!("error applying pending gamma change: {err:?}");
+                            }
+                        }
+                    }
                 }
 
                 // Add new devices.
@@ -839,6 +857,7 @@ impl Tty {
             compositor,
             dmabuf_feedback,
             gamma_props,
+            pending_gamma_change: None,
             vblank_frame: None,
             vblank_frame_name,
             time_since_presentation_plot_name,
@@ -1292,7 +1311,7 @@ impl Tty {
         }
     }
 
-    pub fn set_gamma(&mut self, output: &Output, ramp: Option<&[u16]>) -> anyhow::Result<()> {
+    pub fn set_gamma(&mut self, output: &Output, ramp: Option<Vec<u16>>) -> anyhow::Result<()> {
         let tty_state = output.user_data().get::<TtyOutputState>().unwrap();
         let crtc = tty_state.crtc;
 
@@ -1300,8 +1319,15 @@ impl Tty {
             .devices
             .get_mut(&tty_state.node)
             .context("missing device")?;
-
         let surface = device.surfaces.get_mut(&crtc).context("missing surface")?;
+
+        // Cannot change properties while the device is inactive.
+        if !self.session.is_active() {
+            surface.pending_gamma_change = Some(ramp);
+            return Ok(());
+        }
+
+        let ramp = ramp.as_deref();
         if let Some(gamma_props) = &mut surface.gamma_props {
             gamma_props.set_gamma(&device.drm, ramp)
         } else {
diff --git a/src/handlers/mod.rs b/src/handlers/mod.rs
index d027194c..e5df8b43 100644
--- a/src/handlers/mod.rs
+++ b/src/handlers/mod.rs
@@ -460,7 +460,7 @@ impl GammaControlHandler for State {
         }
     }
 
-    fn set_gamma(&mut self, output: &Output, ramp: Option<&[u16]>) -> Option<()> {
+    fn set_gamma(&mut self, output: &Output, ramp: Option<Vec<u16>>) -> Option<()> {
         match self.backend.tty().set_gamma(output, ramp) {
             Ok(()) => Some(()),
             Err(err) => {
diff --git a/src/protocols/gamma_control.rs b/src/protocols/gamma_control.rs
index 07e5a848..083710ed 100644
--- a/src/protocols/gamma_control.rs
+++ b/src/protocols/gamma_control.rs
@@ -28,7 +28,7 @@ pub struct GammaControlManagerGlobalData {
 pub trait GammaControlHandler {
     fn gamma_control_manager_state(&mut self) -> &mut GammaControlManagerState;
     fn get_gamma_size(&mut self, output: &Output) -> Option<u32>;
-    fn set_gamma(&mut self, output: &Output, ramp: Option<&[u16]>) -> Option<()>;
+    fn set_gamma(&mut self, output: &Output, ramp: Option<Vec<u16>>) -> Option<()>;
 }
 
 pub struct GammaControlState {
@@ -162,8 +162,8 @@ where
                 trace!("setting gamma for output {}", output.name());
 
                 // Start with a u16 slice so it's aligned correctly.
-                let mut buf = vec![0u16; data.gamma_size as usize * 3];
-                let buf = bytemuck::cast_slice_mut(&mut buf);
+                let mut gamma = vec![0u16; data.gamma_size as usize * 3];
+                let buf = bytemuck::cast_slice_mut(&mut gamma);
                 let mut file = File::from(fd);
                 {
                     let _span = tracy_client::span!("read gamma from fd");
@@ -195,7 +195,6 @@ where
                         }
                     }
                 }
-                let gamma = bytemuck::cast_slice(buf);
 
                 if state.set_gamma(&output, Some(gamma)).is_none() {
                     resource.failed();