An issue with EDP on Version R24.2.3

When running the R24.2.3, and the config the 2nd video output as eDP,
TX1 outputs the eDP signal properly according to the read EDID.

But after 1 or 2 dettach and then attach the eDP cable,
TX1 may output the eDP in 640x480 or 720x480 or …etc randomly.

After investigation, we found that the function “static int tegra_fb_set_par(struct fb_info *info)” in fb.c, its parameters carries the wrong contents,
such as 640x480 or 720x480 …etc randomly.
Also the HDMI-audio-out is shut-down. I have to restart the media player to make the HDMI-audio-out enabled.
(headset output works normally all the time.)

It seems its the most top interface in kernel source.

Can somebody help to fix this?

Hi,

I remember we disable audio output for eDP on TX1. Also, for all platform (tx1/tx2/xavier), eDP does not support hotplug on our driver.

Hi,
This phenomenon does not happen every time, but occasionally, it basically supports the hotplug phenomenon. And there is no such problem after version R28.

michaelyang,

I am not sure about your case.

In fact, we enable HPD during display boot up and use it to read EDID. That is, eDP driver only use the HPD mechanism during boot up.

Please elaborate “But after 1 or 2 dettach and then attach the eDP cable,
TX1 may output the eDP in 640x480 or 720x480 or …etc randomly.”

Do you hotplug your eDP cable when system already boots up?