[PTN3460] Ubuntu doesn't see new edid, but after reboot is fine

I have a custom design board that is connected PTN3460 to Displayport (SODIMM pins 41,39,47,45,91,90). I use Jetpack 4.6.1. I prepared the initialization of this IC via I2C (I write custom EDID). After initialization, the system doesn’t see a new resolution but after rebooting the system (power supply still connected) , edid is detected ok. I see two solutions for it:

  1. Restart GPU in Jetson Nano. Can you say how can I do it?
  2. Disable DisplayPort in the device tree and turn on display port after sending initialization to PTN3460. Can you say how to control enable/disable DisplayPort in the terminal?

I attach two logs from dmesg:


Is this “ic initialization” also done by the kernel driver?

I made PTN3460 initialization over I2C only. I think that Jetson can read edid from PTN3460 after initialization. Sometimes I don’t need to make Jetson reboot, so I think that I don’t have to change anything in kernel drivers

Ahh… what I wanted to ask is how do you do this “initialization with I2C only”?

Make it more easier to understand, you don’t need to “initialize” peripherals by yourself each time because there should be a driver to help do this part of work.

For example, I don’t need to initialize the tegra usb controller manually in each boot because the kernel driver would help me do that.

Similar logic, do you have any kernel driver that is for initializing this PTN3460 chip? I cannot understand what kind of “i2c work” has to be done by you here.

I could have written before that I prepare a test platform for this product, so I want to display all errors during the test. I want to run up a system with HDMI, then I want to run the test script.
Is it possible to restart GPU in Jetson Nano? Or turn on the Displayport after starting the system?

I think a better way is you prepare a kernel driver that is initialize this PTN3460 board before the tegradc driver…

GPU driver and display driver are two different things. GPU driver is already a module which could be loaded/unloaded during runtime, but we don’t make display driver(tegradc) to module so it cannot be turn on/off during runtime.

Ok. Thank you for the clarification.

This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.