Dear all, I am working on a stereoscopic vision system based on a Xavier NX. The system uses a 5.5 inches LCD 1440x2560@50Hz (yes, the screen ratio is 9:16). The screen works correctly in Windows and Linux on x64 architecture. It also works on Tegra TX2 with Jetpack 3.3. Whereas on Tegra TX2 with Jetpack 4.x and on Xavier N X development kit it does not work.
X works correctly but it configures the LCD with a resolution of 640x350@85Hz and the LCD stays black, however I can use VNC to access the desktop and xrandr says that the only available resolution for the screen is 640x350@85Hz.
I cannot get the EDID with sudo get-edid, as I get:
This is read-edid version 3.0.2. Prepare for some fun.
Attempting to use i2c interface
No EDID on bus 1
No EDID on bus 2
No EDID on bus 3
No EDID on bus 4
Permission denied opening i2c. Run as root!
I’m sorry nothing was successful. Maybe try some other arguments
if you played with them, or send an email to Matthew Kern email@example.com.
I can, however, find the EDID in /sys/kernel/debug/tegradc.0/edid. The content is attached and is not conformant: the final lines of edid-decode output are:
EDID block does NOT conform to EDID 1.3!
Name descriptor not terminated with a newline
Detailed block string not properly terminated
I created a correct EDID (attached) and I used it to fill in default_720p_edid and I set use_fallback to true. The result after flashing is the same (I added some pr_warn in edid.c code to make sure that the fallback edid is used).
For completeness, if I connect the LCD to a Tegra TX2 flashed with Jetpack 3.3 I got a similar behavior, as X configure the LCD with a resolution of 640x350@85, but on that platform I can change the resolution to 1440x2560@50 with xrandr.
I would like to know if it is possible to use a resolution of 1440x2560@50Hz on Jetson NX and in case how I can force it. I would also be interested in understanding why Jetpack 4 on Tegra TX2 does not support that LCD while Jetpack 3.3 supports I think this may help me in solving the problem.
Thanks in advance,