DP: No output on Android 14 with FullHD monitor

Edge2 Android
1

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.

2

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

3

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

4

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

5

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?

6

Okay, I’ll take a look at this issue

7

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

8

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.