I have a laptop. As soon as I connect my external monitor via HDMI, dmesg provides the following error:
[drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 254 Raw EDID: ff ff ff ff ff ff ff ff 1a b3 45 07 01 01 01 01 21 11 01 03 80 2f 1e 82 2a ee 95 a3 54 4c 99 26 0f 50 54 a5 4b 00 95 0f 81 80 81 40 71 4f 95 00 b3 00 81 c0 01 01 21 39 90 30 62 1a 27 40 68 b0 36 00 da 28 11 00 00 1c 00 00 00 ff 00 59 45 33 4c 30 31 30 32 36 33 0a 20 20 00 00 00 fd 00 38 4b 1f 53 0f 00 0a 20 20 20 20 20 20 00 00 00 fc 00 58 32 32 57 2d 31 0a 20 20 20 20 20 20 00 53 i915 0000:00:02.0: HDMI-A-1: EDID block 0 invalid. When I connect the external monitor via VGA, it works fine. The external monitor also used to work fine via HDMI/DVI quite some time ago. xrandr has the following output (the external monitor in connected by VGA and also by HDMI/DVI): Screen 0: minimum 320 x 200, current 1600 x 900, maximum 8192 x 8192 LVDS1 connected 1600x900+0+0 (normal left inverted right x axis y axis) 382mm x 214mm 1600x900 60.0*+ 1440x900 59.9 1360x768 59.8 60.0 1152x864 60.0 1024x768 60.0 800x600 60.3 56.2 640x480 59.9 VGA1 connected (normal left inverted right x axis y axis) 1680x1050 60.0 + 1280x1024 75.0 60.0 1440x900 75.0 59.9 1280x960 60.0 1152x864 75.0 1280x720 60.0 1024x768 75.1 60.0 800x600 75.0 60.3 640x480 75.0 60.0 720x400 70.1 HDMI1 disconnected (normal left inverted right x axis y axis) DP1 disconnected (normal left inverted right x axis y axis) So I can't even active the monitor by HDMI (xrandr --output HDMI1 --auto hs no effect). As anyone found a workaround? -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/914437 Title: Second display not recognized anymore; "EDID checksum is invalid" To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-ati/+bug/914437/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs