xrandr omits EDID modelines found by get-edid/parse-edid
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
x11-xserver-utils (Ubuntu) |
New
|
Undecided
|
Unassigned |
Bug Description
OS: Ubuntu 19.04
Aaffected package: x11-xserver-utils 7.7+8
Related package: read-edid 3.0.2-1build1
I have a monitor capable of 2560x1440 display for which xrandr fails to detect 2560x1440 as a valid resolution:
==== output from xrandr --prop ====
$ sudo xrandr --prop
Screen 0: minimum 320 x 200, current 1920 x 1080, maximum 16384 x 16384
DVI-I-1 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 597mm x 336mm
EDID:
dithering depth: auto
dithering mode: auto
scaling mode: None
color vibrance: 150
vibrant hue: 90
underscan vborder: 0
underscan hborder: 0
underscan: off
1920x1080* 60.00 50.00 59.94
1920x1080i 60.00 50.00 59.94
1600x1200 60.00
1680x1050 59.88
1400x1050 59.95
1280x1024 75.02 60.02
1440x900 59.90
1280x960 60.00
1152x864 75.00
1280x720 60.00 50.00 59.94
1440x576 50.00
1024x768 75.03 70.07 60.00
832x624 74.55
800x600 72.19 75.00 60.32 56.25
720x576 50.00
720x480 60.00 59.94
640x480 75.00 72.81 66.67 60.00 59.94
720x400 70.08
=======
The effect is that after boot and before login, the X display is a narrow letterbox on the screen. After I login, the X display is "corrected" to 1920x1080.
However, get-edid/parse-edid does detect 2560x1440 as "Mode 0":
==== output from get-edid| parse-edid ====
$ sudo get-edid| parse-edid
This is read-edid version 3.0.2. Prepare for some fun.
Attempting to use i2c interface
No EDID on bus 2
No EDID on bus 3
No EDID on bus 4
No EDID on bus 5
No EDID on bus 6
No EDID on bus 7
No EDID on bus 8
No EDID on bus 9
No EDID on bus 10
No EDID on bus 11
No EDID on bus 12
2 potential busses found: 0 1
Will scan through until the first EDID is found.
Pass a bus number as an option to this program to go only for that one.
Bus 0 doesn't really have an EDID...
256-byte EDID successfully retrieved from i2c bus 1
Looks like i2c was successful. Have a good day.
Checksum Correct
Section "Monitor"
Identifier "HQ272PPB"
ModelName "HQ272PPB"
VendorName "HSD"
# Monitor Manufactured week 28 of 2017
# EDID version 1.3
# Digital Display
DisplaySize 600 340
Gamma 2.20
Option "DPMS" "true"
Horizsync 31-89
VertRefresh 56-75
# Maximum pixel clock is 300MHz
#Not giving standard mode: 1280x720, 60Hz
#Not giving standard mode: 1280x960, 60Hz
#Not giving standard mode: 1280x1024, 60Hz
#Not giving standard mode: 1400x1050, 60Hz
#Not giving standard mode: 1440x900, 60Hz
#Not giving standard mode: 1600x1200, 60Hz
#Not giving standard mode: 1680x1050, 60Hz
#Not giving standard mode: 1920x1080, 60Hz
#Extension block found. Parsing...
Modeline "Mode 16" 148.50 1920 2008 2052 2200 1080 1084 1089 1125 +hsync +vsync
Modeline "Mode 0" 241.50 2560 2608 2640 2720 1440 1443 1448 1481 +hsync -vsync
Modeline "Mode 1" 148.500 1920 2008 2052 2200 1080 1084 1089 1125 +hsync +vsync
Modeline "Mode 2" 74.250 1920 2008 2052 2200 1080 1082 1087 1125 +hsync +vsync interlace
Modeline "Mode 3" 74.250 1280 1390 1420 1650 720 725 730 750 +hsync +vsync
Modeline "Mode 4" 27.027 720 736 798 858 480 489 495 525 -hsync -vsync
Modeline "Mode 5" 27.027 720 736 798 858 480 489 495 525 -hsync -vsync
Modeline "Mode 6" 27.027 1440 1478 1602 1716 480 484 487 525 -hsync -vsync interlace
Modeline "Mode 7" 27.000 1440 1464 1590 1728 576 578 581 625 -hsync -vsync interlace
Modeline "Mode 8" 25.200 640 656 752 800 480 490 492 525 -hsync -vsync
Modeline "Mode 9" 74.250 1920 2448 2492 2640 1080 1082 1089 1125 +hsync +vsync interlace
Modeline "Mode 10" 148.500 1920 2448 2492 2640 1080 1084 1089 1125 +hsync +vsync
Modeline "Mode 11" 27.000 720 732 796 864 576 581 586 625 -hsync -vsync
Modeline "Mode 12" 74.250 1280 1720 1760 1980 720 725 730 750 +hsync +vsync
Modeline "Mode 13" 54.000 1440 1464 1592 1728 576 581 586 625 -hsync -vsync
Modeline "Mode 14" 27.000 1440 1464 1590 1728 576 578 581 625 -hsync -vsync interlace
Modeline "Mode 15" 27.027 1440 1478 1602 1716 480 484 487 525 -hsync -vsync interlace
Modeline "Mode 17" 74.25 1920 2008 2052 2200 540 542 547 562 +hsync +vsync interlace
Modeline "Mode 18" 74.25 1280 1390 1430 1650 720 725 730 750 +hsync +vsync
Modeline "Mode 19" 27.00 720 736 798 858 480 489 495 525 -hsync -vsync
Option "PreferredMode" "Mode 16"
EndSection
=======
So, this is not an obvious case of a buggy monitor EDID.
I am able to workaround this using the steps https:/