DP: No output on Android 14 with FullHD monitor

When using my own Android 14 build with 2 1080p screens, I am experiencing an issue very similar the one described here: Edge 2 - Android 13 - Image Distorted on Display Connected to Display Port dp0 (USB-C to HDMI)

However, when flashing the edge2-android-13-v241206.img official image, the problem is not there (I can"t test with the official Android 14 build unfortunately, because of this issue 4K resolution "hardcoded" in Android 14 images - #4 by xiong.zhang).

I have also cherry-picked the following commit DP: fix 1080p cannot work for dp [2/2] · khadas/linux@4a8a65d · GitHub that seems to fix the issue in Android 13 kernels, but it does not help.

Please also note that the issue can’t be reproduce when using 2 monitors with a 1920x720 resolution.

Have you applied this patch to Android 14

We haven’t updated this code on GitHub yet. Can you fix the code modification I provided in this post by typing it on your code

There are two places where this patch needs to be applied. Under u-boot, the GitHub link is as follows

Yes, otherwise the other 1080p monitor connected over HDMI would also not work

Ok, I have now applied the following patches:
kernel-6.1:

u-boot:

I still don"t see any improvement by default.
But, if I tweak the resolution manually to 1920x1080p59.94, then, after a reboot it works.

Is there any additional patch I should apply to make it works by default like on Android 13?

Okay, I’ll take a look at this issue

Can you provide me with a more detailed description of the scenario and steps in which you reproduced the problem, such as the detailed parameters of each device

What do you mean by “detailed parameters”?

Ok, my setup is the following: 2x FullHD Monitor (this one: Amazon.de), one connected directly over HDMI, and the other one connected over an USB-C to HDMI cable.

The display EDID looks like this:

00 ff ff ff ff ff ff 00 2d c8 3b 2a 01 01 01 01
1c 20 01 03 80 21 16 78 3a 91 54 a3 57 60 9a 24
0e 4e 55 03 08 00 95 00 95 00 81 00 45 40 a9 c0
b3 00 81 80 8b c0 7d 4b 80 a0 72 b0 2d 40 50 c8
46 48 fe 22 11 00 00 1e 02 3a 80 18 71 38 2d 40
58 2c 45 00 59 c2 10 00 00 1e 00 00 00 fd 00 32
41 1e a0 24 00 0a 20 20 20 20 20 20 00 00 00 fc
00 31 30 2e 31 27 20 6d 6f 6e 69 74 6f 72 01 1e

02 03 2c f1 4c 90 20 05 13 04 5d 04 12 05 11 1f
10 23 09 07 07 83 01 00 00 67 03 0c 00 10 00 38
44 e3 05 e3 01 e6 06 07 01 4e 50 5a 01 1d 00 72
51 d0 1e 20 6e 28 55 00 df a4 21 00 00 1e 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 fa

As mentioned, when I flash the official Android 13 image (edge2-android-13-v241206.img), everything works fine and the resolution is properly set by default (I don"t have to go in the settings app, and force 1920x1080)

However, when building a 14 version, applying the patches mentioned above, the display connected over USB-C (DP) gets scrambled (Even the OSD is not properly rendered). The only way that I found until now to make it work, is to force the 1920x1080 resolution in the settings app: When doing so, I get a proper rendering.