Observed on Intel Ivy Bridge. Save work first! 1. Change the tearing prevention from "Full screen repaints" to "Automatic" or vice-versa, and Apply. 2. Move some windows around: observe full-screen black flickering, other windows being partially painted over the active window while typing, and general artefacts. Either 3a. Logout, and confirm with Ok at the logout screen: session freezes with the logout screen stuck on the screen. Or 3b. Keep triggering the snap animation by snapping a window against a screen edge but not letting go: observe snap animation displays a garbage texture. Continue for about 10 seconds: graphics freezes, cpu goes to 100%, and disk starts swapping. 4. Try to VT switch: nothing happens. 5. Trigger SysRq+I: get a VT, but it is frozen, and a reboot is necessary, even though kernel is responsive. (If you are lucky, you may get the SDDM greeter, and you can login again normally.)
(In reply to pbs3141 from comment #0) > 1. Change the tearing prevention from "Full screen repaints" to "Automatic" > or vice-versa, and Apply. > > 2. Move some windows around: observe full-screen black flickering, other > windows being partially painted over the active window while typing, and > general artefacts. Can confirm this. Full scale black flickering happens when there are no maximized windows in the background. General bad artefacts happen either way. > > Either > 3a. Logout, and confirm with Ok at the logout screen: session freezes with > the logout screen stuck on the screen. I was able to logout but kwin crashed with a truncated core dump so no luck. > > Or > 3b. Keep triggering the snap animation by snapping a window against a screen > edge but not letting go: observe snap animation displays a garbage texture. > Continue for about 10 seconds: graphics freezes, cpu goes to 100%, and disk > starts swapping. The "garbage texture" is reproducible but cpu remained quiet. > 4. Try to VT switch: nothing happens. > > 5. Trigger SysRq+I: get a VT, but it is frozen, and a reboot is necessary, > even though kernel is responsive. > (If you are lucky, you may get the SDDM greeter, and you can login again > normally.) This was not reproducible. It is probably specific to your hardware. Please mark the bug confirmed.
Can sometimes reproduce garbage animations after changing tearing prevention - but where rarely - possible after visiting some System Settings modules Cannot reproduce session freeze Plasma: 5.13.2 Apps: 18.04.2 Frameworks: 5.47.0 Qt: 5.11.1 Kernel: 4.18.0-1-MANJARO OS: Netrunner Rolling Video: Intel 4400 Driver: xf86-video-intel 1:2.99.917+831+ge7bfc906-1 Mesa 3D: 18.1.3 Screen: 1600x900 Xorg: 1.20 Wayland: 1.15.0-1 Wayland Protocols: 1.14-1
Thank you for the report. As it has been a while since this was reported, can you please test and confirm if this issue is still occurring or if this bug report can be marked as resolved. I have set the bug status to "needsinfo" pending your response, please change back to "reported" or "resolved/worksforme" when you respond, thank you.