Bugzilla – Bug 1226881
off-by-one with xrandr in screen size from a two display setup with nvidia drivers
Last modified: 2024-06-25 09:28:54 UTC
Today, I debugged a strange x11vnc issue, that results in a strange effect: when enabling the on-screen-keyboard on my tablet, it paints most areas black. After messing with a bunch of x11vnc options, I noticed: Jun 24 12:19:42 desktop bash[3778]: 24/06/2024 12:19:42 Sending rfbEncodingExtDesktopSize for size (5119x1600) Jun 24 12:19:42 desktop bash[3778]: 24/06/2024 12:19:42 Client requested resolution change to (2560x1600) Jun 24 12:19:43 desktop bash[3778]: 24/06/2024 12:19:43 Sending rfbEncodingExtDesktopSize for size (5119x1600) resize prohibited Digging further on my desktop for this issue: $ xrandr Screen 0: minimum 8 x 8, current 5119 x 1600, maximum 32767 x 32767 DP-2.8 connected 2560x1600+2559+0 (normal left inverted right x axis y axis) 641mm x 401mm 2560x1600 59.97*+ 1920x1200 59.88 1920x1080 60.00 59.94 50.00 23.98 1680x1050 59.95 1600x1200 60.00 1280x1024 75.02 60.02 1280x800 59.81 1280x720 60.00 59.94 50.00 1152x864 75.00 1024x768 75.03 60.00 800x600 75.00 60.32 720x576 50.00 720x480 60.01 59.94 640x480 75.00 59.94 59.93 HDMI-0 disconnected (normal left inverted right x axis y axis) DP-0 connected primary 2560x1600+0+0 (normal left inverted right x axis y axis) 641mm x 401mm 2560x1600 59.97*+ 1920x1200 59.88 1920x1080 60.00 59.94 50.00 23.98 1680x1050 59.95 1600x1200 60.00 1280x1024 75.02 60.02 1280x800 59.81 1280x720 60.00 59.94 50.00 1152x864 75.00 1024x768 75.03 60.00 800x600 75.00 60.32 720x576 50.00 720x480 60.01 59.94 640x480 75.00 59.94 59.93 DP-1 disconnected (normal left inverted right x axis y axis) DP-2 disconnected (normal left inverted right x axis y axis) DP-3 disconnected (normal left inverted right x axis y axis) DP-4 disconnected (normal left inverted right x axis y axis) DP-5 disconnected (normal left inverted right x axis y axis) If I add the horizontal numbers for the two monitors, that makes 5120 pixel, not 5119. This is a classical off-by-one, but where to start digging? Checked Xorg GitLab: https://gitlab.freedesktop.org/xorg/lib/libxrandr https://gitlab.freedesktop.org/xorg/app/xrandr libxrandr didn't received any changes after release, which is on par with our TW release 1.5.4. xrandr saw some unrelated commits after 1.5.2. I tried to apply 71ab94418ead8f59c6124e8b3e53f8df7340f095 already: https://build.opensuse.org/package/show/home:frispete:Tumbleweed/xrandr Did not change anything.
Upstream issue: https://gitlab.freedesktop.org/xorg/lib/libxrandr/-/issues/10
Please try to change the position of the right monitor manually via the appropriate xrandr command to +2560+0
Got feedback that this command succeeds Screen 0: minimum 8 x 8, current 5120 x 1600, maximum 32767 x 32767 but it doesn't help for x11vnc. Maybe because of this Jun 24 12:19:42 desktop bash[3778]: 24/06/2024 12:19:42 Client requested resolution change to (2560x1600) Who is requesting to change to 2560x1600 here?
(In reply to Stefan Dirsch from comment #3) > Got feedback that this command succeeds > > Screen 0: minimum 8 x 8, current 5120 x 1600, maximum 32767 x 32767 > > but it doesn't help for x11vnc. Maybe because of this > > Jun 24 12:19:42 desktop bash[3778]: 24/06/2024 12:19:42 Client requested > resolution change to (2560x1600) > > Who is requesting to change to 2560x1600 here? As it turned out, the culprit really was a one pixel overlap in the screen layout. Since the only major component update affecting this was the plasma desktop, I suspect the culprit was the transition from plasma 5 to plasma 6! Thanks, Stefan for pointing out, closing...