As I said before, troubleshooting this is a pain, because the problem goes away until the system "sleeps" the vid output. However, I was able to check it this morning.
I did a "tail -F Xorg.0.log", and hit return a couple of times to give me some spacing between old output and new. Then I turned on the TV. When it did it's sync up, this is what was written to Xorg.0.log...
[1686663.416] (WW) EDID timing clock 148.50 exceeds claimed max 115MHz, fixing [1686663.416] (II) modeset(0): EDID vendor "WDE", prod id 6160 [1686663.416] (II) modeset(0): Using hsync ranges from config file [1686663.416] (II) modeset(0): Using vrefresh ranges from config file [1686663.416] (II) modeset(0): Printing DDC gathered Modelines: [1686663.416] (II) modeset(0): Modeline "1920x1080"x0.0 138.50 1920 1968 2000 2080 1080 1083 1088 1111 -hsync +vsync (66.6 kHz eP) [1686663.416] (II) modeset(0): Modeline "1920x1080"x0.0 148.50 1920 2008 2052 2200 1080 1084 1089 1125 -hsync +vsync (67.5 kHz e) [1686663.416] (II) modeset(0): Modeline "1280x720"x0.0 74.25 1280 1390 1430 1650 720 725 730 750 +hsync +vsync (45.0 kHz e) [1686663.416] (II) modeset(0): Modeline "1920x1080i"x0.0 74.25 1920 2008 2052 2200 1080 1084 1094 1125 interlace +hsync +vsync (33.8 kHz e) [1686663.416] (II) modeset(0): Modeline "800x600"x0.0 40.00 800 840 968 1056 600 601 605 628 +hsync +vsync (37.9 kHz e) [1686663.416] (II) modeset(0): Modeline "640x480"x0.0 31.50 640 656 720 840 480 481 484 500 -hsync -vsync (37.5 kHz e) [1686663.416] (II) modeset(0): Modeline "640x480"x0.0 25.18 640 656 752 800 480 490 492 525 -hsync -vsync (31.5 kHz e) [1686663.416] (II) modeset(0): Modeline "1024x768"x0.0 78.75 1024 1040 1136 1312 768 769 772 800 +hsync +vsync (60.0 kHz e) [1686663.416] (II) modeset(0): Modeline "1024x768"x0.0 65.00 1024 1048 1184 1344 768 771 777 806 -hsync -vsync (48.4 kHz e) [1686663.416] (II) modeset(0): Modeline "800x600"x0.0 49.50 800 816 896 1056 600 601 604 625 +hsync +vsync (46.9 kHz e) [1686663.416] (II) modeset(0): Modeline "1920x1080"x60.0 172.80 1920 2040 2248 2576 1080 1081 1084 1118 -hsync +vsync (67.1 kHz e) [1686663.416] (II) modeset(0): Modeline "1280x1024"x0.0 108.00 1280 1328 1440 1688 1024 1025 1028 1066 +hsync +vsync (64.0 kHz e) [1686663.416] (II) modeset(0): Modeline "1920x1080"x0.0 148.50 1920 2008 2052 2200 1080 1084 1089 1125 +hsync +vsync (67.5 kHz e) [1686663.416] (II) modeset(0): Modeline "1920x1080"x0.0 74.25 1920 2558 2602 2750 1080 1084 1089 1125 +hsync +vsync (27.0 kHz e) [1686663.416] (II) modeset(0): Modeline "720x480"x0.0 27.00 720 736 798 858 480 489 495 525 -hsync -vsync (31.5 kHz e) [1686663.416] (II) modeset(0): Modeline "1440x480i"x0.0 27.00 1440 1478 1602 1716 480 488 494 525 interlace -hsync -vsync (15.7 kHz e) [1686663.417] (II) modeset(0): Modeline "1920x1080"x0.0 74.25 1920 2008 2052 2200 1080 1084 1089 1125 +hsync +vsync (33.8 kHz e) [1686663.417] (--) modeset(0): HDMI max TMDS frequency 110000KHz
Here's the output of xranr. (I didn't think to run that command before I'd fixed the refresh after doing the above. I'll try it again tonight to see if it changes when it is screwed up.
zeugma@NUC:/var/log$ xrandr Screen 0: minimum 8 x 8, current 1920 x 1080, maximum 16384 x 16384 DVI-I-0 disconnected (normal left inverted right x axis y axis) VGA-0 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 531mm x 299mm 1920x1080 60.00*+ 1680x1050 59.95 1600x1200 60.00 1440x900 59.89 1280x1024 75.02 60.02 1280x960 60.00 1152x864 75.00 1024x768 75.03 70.07 60.00 800x600 75.00 72.19 60.32 56.25 640x480 75.00 72.81 59.94 DVI-I-1 disconnected (normal left inverted right x axis y axis) HDMI-0 disconnected (normal left inverted right x axis y axis)
This is what that little script spits out when I ran it on an old motherboard with onboard video. This is on a minimal install of Ubuntu 16.04 LTS with ratpoison as the window manager, no display manager, and no xorg.conf.
Jan 16 06:20:34 nostr0mo kernel: [ 1.816935] [drm] radeon kernel modesetting enabled. Jan 16 06:20:34 nostr0mo kernel: [ 1.822090] [drm] initializing kernel modesetting (RS780 0x1002:0x9616 0x1458:0xD000). [ 14.018] (II) RADEON(0): Modeline "1600x900"x60.0 108.00 1600 1624 1704 1800 900 901 904 1000 +hsync +vsync (60.0 kHz eP) [ 14.018] (II) RADEON(0): Modeline "1280x1024"x60.0 108.00 1280 1328 1440 1688 1024 1025 1028 1066 +hsync +vsync (64.0 kHz e) [ 14.018] (II) RADEON(0): Modeline "1440x900"x59.9 106.50 1440 1520 1672 1904 900 903 909 934 -hsync +vsync (55.9 kHz e) [ 14.018] (II) RADEON(0): Modeline "1280x720"x60.0 74.25 1280 1390 1430 1650 720 725 730 750 +hsync +vsync (45.0 kHz e) [ 14.018] (II) RADEON(0): Modeline "1024x768"x60.0 65.00 1024 1048 1184 1344 768 771 777 806 -hsync -vsync (48.4 kHz e) [ 14.018] (II) RADEON(0): Modeline "800x600"x60.3 40.00 800 840 968 1056 600 601 605 628 +hsync +vsync (37.9 kHz e) [ 14.018] (II) RADEON(0): Modeline "640x480"x60.0 25.20 640 656 752 800 480 490 492 525 -hsync -vsync (31.5 kHz e) [ 14.018] (II) RADEON(0): Modeline "720x400"x70.1 28.32 720 738 846 900 400 412 414 449 -hsync +vsync (31.5 kHz e) Screen 0: minimum 320 x 200, current 1600 x 900, maximum 8192 x 8192 VGA-0 connected primary 1600x900+0+0 (normal left inverted right x axis y axis) 443mm x 249mm 1600x900 60.00*+ 1280x1024 60.02 1440x900 59.89 1280x720 60.00 1024x768 60.00 800x600 60.32 640x480 60.00 720x400 70.08I assume that the kernel modesetting has something to do with getting the correct display resolution without an xorg.conf.
If you look at
man Xorgthere is a -configure option that will create an xorg.conf file for you.
caveat: I have never done this, and I don't know how it works.