https://bugzilla.kernel.org/show_bug.cgi?id=204181 --- Comment #40 from Sergey Kondakov (virtuousfox@xxxxxxxxx) --- (In reply to Alex Deucher from comment #39) > (In reply to Sergey Kondakov from comment #38) > Here is your issue: "simple 2x1080p" > > multiple display are really hard to deal with. The display timing may be > different, the blanking periods may not align, etc. X uses a single surface > for each multi-display desktopso when you are updating multiple displays, if > the timings are not aligned, one display will show older content. For this > to work smoothly, you really need the compositor to have each display using > it's own set of buffers and doing vsynced rendering to each display > separately. I little bit strange to call 2x1080p on AMD's fancy 5-port GPU (+ possible DP multiplexing) "my issue". If anything is an issue with AMD's modern output controllers it's the lack of analogue signal in DVI port for my proper 1280x1024@89 CRT monitor with majestic >10k:1 contrast. Timing on both outputs is definitively different, though. I still cannot fathom how is it still that all outputs are lumped together like that. Anyway, I was searching on my suspicion about kwin's vsync behaviour and stumbled on this treat: https://bugs.kde.org/show_bug.cgi?id=395632#c45 - new kwin developer working on that and multi-threaded per-output vsync _right now_, wants testers. Surely, this new version of kwin will "blow up" kernel module with this page-flipping bug ! And he would really benefit from your advices. Then we might not even need TearFree anywhere anymore ! https://phabricator.kde.org/T11071 - quite a progress already. Aims to make double-only per-output mandatory vsync via GLX_OML_sync_control. Right now `qdbus-qt5 org.kde.KWin /KWin supportInformation` says: … maxFpsInterval: 16666666 refreshRate: 0 vBlankTime: 6000000 glStrictBinding: false glStrictBindingFollowsDriver: true … Screens ======= Multi-Head: no Active screen follows mouse: no Number of Screens: 2 Screen 0: --------- Name: DVI-D-0 Geometry: 0,0,1920x1080 Scale: 1 Refresh Rate: 72.9249 Screen 1: --------- Name: HDMI-A-0 Geometry: 1920,0,1920x1080 Scale: 1 Refresh Rate: 71.8263 glxgears shows proper FPS (~72.923) but, judging by that bug, it's either mistiming updates or "cutting out" some frames. It will not tear if it would let apps render at their pace and then limit its own output to 60, isn't it ? And I'm as clueless as those bug-reporters on how to check its real rate on currently released version. -- You are receiving this mail because: You are watching the assignee of the bug. _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
