I can add more info. 1. I can not reproduce freeze if I stop lightdm and launch just xterm
startx /usr/bin/startx Although when I switch between LVDS1 and VGA1 xrandr --output LVDS1 --off --output VGA1 --auto xrandr --output VGA1 --off --output LVDS1 --auto approximately in a half of cases I get blank screen. I can restore the image by switching to a console [Ctrl+Alt+F1] and back. I do not see any errors in dmesg or Xorg.0.log 2. I have not managed to reproduce freeze in unity-2d when only xterm is running. The problem with blank screen persists. After several switching I have noticed [drm:drm_mode_getfb] *ERROR* invalid framebuffer id in dmesg output. More switching leads to more such lines. At certain moment xrandr --output VGA1 --off --output LVDS1 --auto failed with the following error: xrandr: cannot find crtc for output LVDS1 Nothing unusual in xrandr output: xrandr Screen 0: minimum 320 x 200, current 1600 x 1200, maximum 8192 x 8192 LVDS1 connected (normal left inverted right x axis y axis) 1280x800 60.0 + 1024x768 60.0 800x600 60.3 56.2 640x480 59.9 VGA1 connected 1600x1200+0+0 (normal left inverted right x axis y axis) 408mm x 306mm 1600x1200 59.8*+ 1280x1024 75.0 60.0 1152x864 75.0 1024x768 85.0 75.1 60.0 832x624 74.6 800x600 85.1 75.0 60.3 640x480 75.0 60.0 59.9 720x400 70.1 Surprisingly [Fn+F6] switched image to internal screen and xrandr started to work again. I am afraid that some applications will be able to freeze X server even when unity-2d is running. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/992391 Title: [i915] xserver freeze on switching VGA1/LVDS1 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/992391/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
