SUMMARY If I move a part of Kate window outside display borders, and then I insert some new lines among a text, the text will start flickering (and Kate window too sometimes). As soon I bring Kate window inside display borders, everything is back to normal. See this video to better understand https://youtu.be/RNYV4Yonkos SOFTWARE/OS VERSIONS Fedora 32 Kate 20.04.1 KDE Frameworks 5.70.0 Qt 5.14.2 xcb window system AMD Radeon RX480 with amdgpu drivers included in kernel 5.7.11-200.fc32.x86_64 4k display $ qdbus org.kde.KWin /KWin supportInformation Version ======= KWin version: 5.18.5 Qt Version: 5.14.2 Qt compile version: 5.14.2 XCB compile version: 1.13.1 Operation Mode: X11 only Build Options ============= KWIN_BUILD_DECORATIONS: yes KWIN_BUILD_TABBOX: yes KWIN_BUILD_ACTIVITIES: yes HAVE_DRM: yes HAVE_GBM: yes HAVE_EGL_STREAMS: yes HAVE_X11_XCB: yes HAVE_EPOXY_GLX: yes HAVE_WAYLAND_EGL: yes X11 === Vendor: Fedora Project Vendor Release: 12008000 Protocol Version/Revision: 11/0 SHAPE: yes; Version: 0x11 RANDR: yes; Version: 0x14 DAMAGE: yes; Version: 0x11 Composite: yes; Version: 0x4 RENDER: yes; Version: 0xb XFIXES: yes; Version: 0x50 SYNC: yes; Version: 0x31 GLX: yes; Version: 0x0 Decoration ========== Plugin: org.kde.breeze Theme: Plugin recommends border size: None Blur: 0 onAllDesktopsAvailable: true alphaChannelSupported: true closeOnDoubleClickOnMenu: false decorationButtonsLeft: 0, 2 decorationButtonsRight: 6, 3, 4, 5 borderSize: 0 gridUnit: 14 font: Droid Sans [1ASC],11,-1,5,50,0,0,0,0,0 smallSpacing: 3 largeSpacing: 14 Platform ========== Name: KWin::X11StandalonePlatform Options ======= focusPolicy: 0 nextFocusPrefersMouse: false clickRaise: true autoRaise: false autoRaiseInterval: 0 delayFocusInterval: 0 shadeHover: false shadeHoverInterval: 250 separateScreenFocus: false placement: 4 focusPolicyIsReasonable: true borderSnapZone: 10 windowSnapZone: 10 centerSnapZone: 0 snapOnlyWhenOverlapping: false rollOverDesktops: true focusStealingPreventionLevel: 1 operationTitlebarDblClick: 5000 operationMaxButtonLeftClick: 5000 operationMaxButtonMiddleClick: 5015 operationMaxButtonRightClick: 5014 commandActiveTitlebar1: 0 commandActiveTitlebar2: 28 commandActiveTitlebar3: 2 commandInactiveTitlebar1: 4 commandInactiveTitlebar2: 28 commandInactiveTitlebar3: 2 commandWindow1: 7 commandWindow2: 8 commandWindow3: 8 commandWindowWheel: 28 commandAll1: 10 commandAll2: 3 commandAll3: 14 keyCmdAllModKey: 16777251 showGeometryTip: false condensedTitle: false electricBorderMaximize: true electricBorderTiling: true electricBorderCornerRatio: 0.25 borderlessMaximizedWindows: false killPingTimeout: 5000 hideUtilityWindowsForInactive: true compositingMode: 1 useCompositing: true hiddenPreviews: 1 glSmoothScale: 2 xrenderSmoothScale: false maxFpsInterval: 16666666 refreshRate: 0 vBlankTime: 6000000 glStrictBinding: true glStrictBindingFollowsDriver: true glCoreProfile: true glPreferBufferSwap: 101 glPlatformInterface: 1 windowsBlockCompositing: true Screen Edges ============ desktopSwitching: false desktopSwitchingMovingClients: false cursorPushBackDistance: 1x1 timeThreshold: 150 reActivateThreshold: 350 actionTopLeft: 0 actionTop: 0 actionTopRight: 0 actionRight: 0 actionBottomRight: 0 actionBottom: 0 actionBottomLeft: 0 actionLeft: 0 Screens ======= Multi-Head: no Active screen follows mouse: yes Number of Screens: 1 Screen 0: --------- Name: DP-3 Geometry: 0,0,3840x2160 Scale: 1 Refresh Rate: 59.996 Compositing =========== Compositing is active Compositing Type: OpenGL OpenGL vendor string: X.Org OpenGL renderer string: AMD Radeon (TM) RX 480 Graphics (POLARIS10, DRM 3.37.0, 5.7.11-200.fc32.x86_64, LLVM 10.0.0) OpenGL version string: 4.6 (Compatibility Profile) Mesa 20.1.4 OpenGL platform interface: GLX OpenGL shading language version string: 4.60 Driver: RadeonSI GPU class: Arctic Islands OpenGL version: 4.6 GLSL version: 4.60 Mesa version: 20.1.4 Linux kernel version: 5.7.11 Direct rendering: Requires strict binding: yes GLSL shaders: yes Texture NPOT support: yes Virtual Machine: no OpenGL 2 Shaders are used Painting blocks for vertical retrace: no Loaded Effects: --------------- kwin4_effect_sessionquit screenshot desktopgrid kwin4_effect_translucency colorpicker kwin4_effect_frozenapp presentwindows kwin4_effect_dialogparent highlightwindow blur contrast startupfeedback kscreen Currently Active Effects: ------------------------- blur contrast Effect Settings: ---------------- kwin4_effect_sessionquit: isActiveFullScreenEffect: false screenshot: desktopgrid: zoomDuration: 300 border: 10 desktopNameAlignment: 0 layoutMode: 0 customLayoutRows: 2 usePresentWindows: true kwin4_effect_translucency: isActiveFullScreenEffect: false colorpicker: kwin4_effect_frozenapp: isActiveFullScreenEffect: false presentwindows: layoutMode: 0 showCaptions: true showIcons: true doNotCloseWindows: false ignoreMinimized: false accuracy: 20 fillGaps: true fadeDuration: 150 showPanel: false leftButtonWindow: 1 rightButtonWindow: 2 middleButtonWindow: 0 leftButtonDesktop: 2 middleButtonDesktop: 0 rightButtonDesktop: 0 kwin4_effect_dialogparent: isActiveFullScreenEffect: false highlightwindow: blur: contrast: startupfeedback: type: 1 kscreen:
That is not something Kate itself will trigger. Might this be some issue with KWin or the graphics stack?
Can you check if disabling buffer age fixes the bug? env KWIN_USE_BUFFER_AGE=0 kwin_x11 --replace
(In reply to Vlad Zahorodnii from comment #2) > Can you check if disabling buffer age fixes the bug? > > env KWIN_USE_BUFFER_AGE=0 kwin_x11 --replace Right now I cannot manage to reproduce the problem. As soon I will manage again to reproduce it, I will test that setting
No feedback after three weeks. Please reopen if it happens again.
While experiencing the problem, I runned $ env KWIN_USE_BUFFER_AGE=0 kwin_x11 --replace & and the problem ceased. To be sure that it was really KWIN_USE_BUFFER_AGE=0 that was fixing the problem (and not just a kwin restart), I opened another konsole session and runned $ kwin --replace & (so without KWIN_USE_BUFFER_AGE=0) and the problem started to happen again. Then I runned again $ env KWIN_USE_BUFFER_AGE=0 kwin_x11 --replace & and the problem was no longer happening. I tried this test various times and it confirmed that KWIN_USE_BUFFER_AGE=0 should fix the problem
No longer being able to reproduce since a long time