X does not use Detailed Timing Descriptor from monitor's EDID.

[stolk]

My monitor is a panel with native 1280x768 resolution, which is described in the EDID's DTD.

X will come up using a 1024x768 mode instead.

My EDID info:

Block 0, Base EDID:
  EDID Structure Version & Revision: 1.3
  Vendor & Product Identification:
    Manufacturer: SAM
    Model: 135
    Serial Number: 1297035575
    Made in: week 8 of 2003
  Basic Display Parameters & Features:
    Digital display
    Maximum image size: 30 cm x 23 cm
    Gamma: 2.25
    DPMS levels: Off
    RGB color display
    First detailed timing is the preferred timing
  Color Characteristics:
    Red  : 0.6318, 0.3574
    Green: 0.2890, 0.5957
    Blue : 0.1425, 0.0849
    White: 0.3164, 0.3378
  Established Timings I & II:
    IBM     :   720x400    70.081663 Hz   9:5     31.467 kHz     28.320000 MHz
    DMT 0x04:   640x480    59.940476 Hz   4:3     31.469 kHz     25.175000 MHz
    DMT 0x05:   640x480    72.808802 Hz   4:3     37.861 kHz     31.500000 MHz
    DMT 0x06:   640x480    75.000000 Hz   4:3     37.500 kHz     31.500000 MHz
    DMT 0x08:   800x600    56.250000 Hz   4:3     35.156 kHz     36.000000 MHz
    DMT 0x09:   800x600    60.316541 Hz   4:3     37.879 kHz     40.000000 MHz
    DMT 0x0a:   800x600    72.187572 Hz   4:3     48.077 kHz     50.000000 MHz
    DMT 0x0b:   800x600    75.000000 Hz   4:3     46.875 kHz     49.500000 MHz
    DMT 0x10:  1024x768    60.003840 Hz   4:3     48.363 kHz     65.000000 MHz
    DMT 0x11:  1024x768    70.069359 Hz   4:3     56.476 kHz     75.000000 MHz
    DMT 0x12:  1024x768    75.028582 Hz   4:3     60.023 kHz     78.750000 MHz
  Standard Timings:
    DMT 0x10:  1024x768    60.003840 Hz   4:3     48.363 kHz     65.000000 MHz
    DMT 0x09:   800x600    60.316541 Hz   4:3     37.879 kHz     40.000000 MHz
    DMT 0x04:   640x480    59.940476 Hz   4:3     31.469 kHz     25.175000 MHz
    DMT 0x12:  1024x768    75.028582 Hz   4:3     60.023 kHz     78.750000 MHz
    DMT 0x0b:   800x600    75.000000 Hz   4:3     46.875 kHz     49.500000 MHz
    DMT 0x06:   640x480    75.000000 Hz   4:3     37.500 kHz     31.500000 MHz
  Detailed Timing Descriptors:
    DTD 1:  1280x768    59.995508 Hz   5:3     47.696 kHz     80.130000 MHz (304 mm x 228 mm)
                 Hfront   64 Hsync 136 Hback  200 Hpol N
                 Vfront    1 Vsync   3 Vback   23 Vpol P
    Display Range Limits:
      Monitor ranges (GTF): 56-75 Hz V, 30-61 kHz H, max dotclock 80 MHz
    Display Product Name: 'SyncMaster'
    Display Product Serial Number: 'H4JW202417'
Checksum: 0x1a

[stolk]

Xorg.0.log

[stolk]

I tried using xrandr --newmode and xrandr --addmode to force it to 1280x768, which gave me a black screen.

Stopping and restarting lightdm resulted in a 1024x768 resolution again.

[dtometzki]

hello stolk,

a simalar issue we had on starfive VF2 and please try

vi /etc/lightdm/lightdm.conf
2) Add display-setup-script=xrandr -s 1280x768 under [Seat:*]
3) Reboot the system or type “systemctl restart lightdm”

Damian