I have a Apple computer hooked up to a 2007 Apple Cinema HD Display with Apple's official mini display port (thunderbolt) to dual-link dvi cable and when I start up in Ubuntu 20.04.3 only the half size (1280x800) display resolution is available.
I can add the higher resolution (2560x1600) using xrandr and I can make it persistent with my .xprofile.
I am curious why xorg is throwing out the modeline from the EDID which is being read properly as far as I can tell from the xorg.0.log, the only complaint I see is where it says the mode is in violation of standard.
Is there something I can adjust so that it will add the modeline.
I will also note that the auto-generated modeline from cvt for 2560x1600 at 60hz does not display properly.
Here are the relevant lines from the xorg.0.log:
[ 1605.612] (II) modeset(0): EDID for output DP-1
[ 1605.612] (II) modeset(0): Manufacturer: APP Model: 9221 Serial#: 33558015
[ 1605.612] (II) modeset(0): Year: 2007 Week: 17
[ 1605.612] (II) modeset(0): EDID Version: 1.3
[ 1605.612] (II) modeset(0): Digital Display Input
[ 1605.612] (II) modeset(0): Max Image Size [cm]: horiz.: 64 vert.: 40
[ 1605.612] (II) modeset(0): Gamma: 2.20
[ 1605.612] (II) modeset(0): DPMS capabilities: Off
[ 1605.612] (II) modeset(0): Supported color encodings: RGB 4:4:4 YCrCb 4:4:4
[ 1605.612] (II) modeset(0): First detailed timing not preferred mode in violation of standard!
[ 1605.612] (II) modeset(0): redX: 0.640 redY: 0.343 greenX: 0.292 greenY: 0.611
[ 1605.612] (II) modeset(0): blueX: 0.146 blueY: 0.074 whiteX: 0.313 whiteY: 0.329
[ 1605.612] (II) modeset(0): Manufacturer's mask: 0
[ 1605.612] (II) modeset(0): Supported detailed timing:
[ 1605.612] (II) modeset(0): clock: 71.0 MHz Image Size: 641 x 401 mm
[ 1605.612] (II) modeset(0): h_active: 1280 h_sync: 1328 h_sync_end 1360 h_blank_end 1440 h_border: 0
[ 1605.612] (II) modeset(0): v_active: 800 v_sync: 803 v_sync_end 809 v_blanking: 823 v_border: 0
[ 1605.612] (II) modeset(0): Supported detailed timing:
[ 1605.612] (II) modeset(0): clock: 268.0 MHz Image Size: 641 x 401 mm
[ 1605.612] (II) modeset(0): h_active: 2560 h_sync: 2608 h_sync_end 2640 h_blank_end 2720 h_border: 0
[ 1605.612] (II) modeset(0): v_active: 1600 v_sync: 1603 v_sync_end 1609 v_blanking: 1646 v_border: 0
[ 1605.612] (II) modeset(0): Serial No: CY71733DXMP
[ 1605.613] (II) modeset(0): Monitor name: Cinema HD
[ 1605.613] (II) modeset(0): Number of EDID sections to follow: 1
[ 1605.613] (II) modeset(0): EDID (in hex):
[ 1605.613] (II) modeset(0): 00ffffffffffff0006102192ff0d0002
[ 1605.613] (II) modeset(0): 111101038040287828fe85a3574a9c25
[ 1605.613] (II) modeset(0): 13505400000001010101010101010101
[ 1605.613] (II) modeset(0): 010101010101bc1b00a0502017303020
[ 1605.613] (II) modeset(0): 360081912100001ab06800a0a0402e60
[ 1605.613] (II) modeset(0): 3020360081912100001a000000ff0043
[ 1605.613] (II) modeset(0): 59373137333344584d500a00000000fc
[ 1605.613] (II) modeset(0): 0043696e656d612048440a0000000155
[ 1605.613] (II) modeset(0): 40010300000000c84801a500a5000102
[ 1605.613] (II) modeset(0): 031919a8000000000000400000000000
[ 1605.613] (II) modeset(0): 00000000000000000000000000000000
[ 1605.613] (II) modeset(0): 00000000000000000000000000000000
[ 1605.613] (II) modeset(0): 00000000000000000000000000000000
[ 1605.613] (II) modeset(0): 00000000000000000000000000000000
[ 1605.613] (II) modeset(0): 00000000000000000000000000000000
[ 1605.613] (II) modeset(0): 00000000000000000000000000000041
[ 1605.613] (II) modeset(0): Printing probed modes for output DP-1
[ 1605.613] (II) modeset(0): Modeline "1280x800"x59.9 71.00 1280 1328 1360 1440 800 803 809 823 +hsync -vsync (49.3 kHz e)
and my .xprofile:
#! /bin/sh
xrandr --newmode "2560x1600" 268.00 2560 2608 2640 2720 1600 1603 1609 1646 -hsync +vsync
xrandr --addmode DP-1 2560x1600
xrandr --output DP-1 --mode 2560x1600
cvt output:
# 2656x1600 59.95 Hz (CVT) hsync: 99.39 kHz; pclk: 361.00 MHz
Modeline "2656x1600_60.00" 361.00 2656 2856 3144 3632 1600 1603 1613 1658 -hsync +vsync
