How to modify the kernel's source code from the screen resolution 1920x1080p@60Hz to 1280x1024p@60Hz...

Hello,

How to change the screen resolution to 1280x1024p@60Hz in Tx2?
It is very appreciate for your any advice.

If you are logged in to the relevant display, do you see this mode in the output from “xrandr”?

If 1280x1024 is there, and if the ID is listed as “HDMI-0”, then this should switch to 1280x1024:

xrandr --output HDMI-0 --mode 1280x1024

If 60Hz is available, then this should also set rate:

xrandr --output HDMI-0 --mode 1280x1024 --rate 60

If the mode is not listed, then likely the driver won’t support it (the driver uses EDID modes).

Hi linuxdev,

Thank you very much.
Do you have the edid of 1280x1024@60Hz?

There is any way to modify the resolution that don’t use the command of xrandr or edid in device tree?

In every monitor cable type other than the old 15-pin VGA D-Sub there is a wire…the DDC wire. This uses i2c communcations to allow the video card to query the monitor for its capabilities…this is communicated in the form of EDID data over that wire. So there is no EDID to modify, it comes directly from your monitor when the video driver queries it. The timings are supplied by the monitor itself since each monitor has different timings.

If you want to see what your monitor supports, then paste the output from this into http://www.edidreader.com:

sudo -s
cat find /sys -name edid
exit

Note that the NVIDIA driver does not support all modes which every monitor might support. If you add this to the “/etc/X11/xorg.conf” Section “Device”, then you will get verbose logs from which the driver will explicitly tell you want it thinks about every mode:

Option  "ModeDebug"

…and then after a reboot look at “/var/log/Xorg.0.log”.

NOTE: The driver itself will refuse anything not in the EDID.

Hi linuxdev,

Thank you very much.
I’m very sorry that the link “http://www.edidreader.com” can’t get in.

And how to change the resolution by modify the code of kernel source?

Hi,

It is not a good solution to modify resolution to what you want without providing edid.

This wiki teaches how to hack edid in kerenel.
https://elinux.org/Jetson_TX2/r28_Display_debug

The only display interface on tegra that does not take EDID as parameter is DSI.

If you are using DSI, you can check the device tree to know how to configure display mode.

Other interfaces require EDID.