From 66712009fb67f655950f1710de0e7a7d9574964b Mon Sep 17 00:00:00 2001
From: Victoria Brekenfeld <victoria@system76.com>
Date: Tue, 22 Jul 2025 17:18:55 +0200
Subject: [PATCH] kms/surface: Only skip cursor updates if the application
 renders consistently

---
 src/backend/kms/surface/mod.rs | 25 ++++++++++++++++++++-----
 1 file changed, 20 insertions(+), 5 deletions(-)

diff --git a/src/backend/kms/surface/mod.rs b/src/backend/kms/surface/mod.rs
index 583c8530..1935805b 100644
--- a/src/backend/kms/surface/mod.rs
+++ b/src/backend/kms/surface/mod.rs
@@ -11,7 +11,10 @@ use crate::{
     state::SurfaceDmabufFeedback,
     utils::prelude::*,
     wayland::{
-        handlers::screencopy::{submit_buffer, FrameHolder, SessionData},
+        handlers::{
+            compositor::recursive_frame_time_estimation,
+            screencopy::{submit_buffer, FrameHolder, SessionData},
+        },
         protocols::screencopy::{
             FailureReason, Frame as ScreencopyFrame, SessionRef as ScreencopySessionRef,
         },
@@ -969,13 +972,24 @@ impl SurfaceThreadState {
         let mut additional_frame_flags = FrameFlags::empty();
         let mut remove_frame_flags = FrameFlags::empty();
 
-        let has_active_fullscreen = {
+        let (has_active_fullscreen, fullscreen_drives_refresh_rate) = {
             let shell = self.shell.read();
             let output = self.mirroring.as_ref().unwrap_or(&self.output);
             if let Some((_, workspace)) = shell.workspaces.active(output) {
-                workspace.get_fullscreen().is_some()
+                if let Some(fullscreen_surface) = workspace.get_fullscreen() {
+                    const _30_FPS: Duration = Duration::from_nanos(1_000_000_000 / 30);
+                    (
+                        true,
+                        fullscreen_surface.wl_surface().is_some_and(|surface| {
+                            recursive_frame_time_estimation(&self.clock, &*surface)
+                                .is_some_and(|dur| dur <= _30_FPS)
+                        }),
+                    )
+                } else {
+                    (false, false)
+                }
             } else {
-                false
+                (false, false)
             }
         };
 
@@ -1009,7 +1023,8 @@ impl SurfaceThreadState {
             anyhow::format_err!("Failed to accumulate elements for rendering: {:?}", err)
         })?;
 
-        if vrr && has_active_fullscreen && !self.timings.past_min_render_time(&self.clock) {
+        if vrr && fullscreen_drives_refresh_rate && !self.timings.past_min_render_time(&self.clock)
+        {
             additional_frame_flags |= FrameFlags::SKIP_CURSOR_ONLY_UPDATES;
         };
         self.timings.set_vrr(vrr);