Fix kdesktop_lock screensaver stuttering on modern GPUs

(cherry picked from commit 4ec011cd55)
6 years ago · bc08650da1
parent 24ee9f5775
commit bc08650da1
1 changed files with 5 additions and 1 deletions
--- a/kdesktop/lock/lockprocess.cc
+++ b/kdesktop/lock/lockprocess.cc
@ -868,7 +868,11 @@ void LockProcess::createSaverWindow()
                info = glXGetVisualFromFBConfig(x11Display(), fbc[j]);
                if( info ) {
                    if (argb_visual) {
-                        if (info->depth < 32) {
+                        // Xorg can only use GPU compositing for ARGB32 8:8:8:8 visuals
+                        // Ensure the selected visual is 8 bits per RGB
+                        // Selecting a non-8-bit visual will result in stuttering and high
+                        // CPU load, while Xorg tries to composite each frame on the CPU!
+                        if ((info->depth < 32) || (info->bits_per_rgb != 8)) {
                            XFree( info );
                            info = NULL;
                            continue;