Blank screen on display with native resolution of 1366 x 768

[dluksza]

Describe the bug
This monitor is not working with Raspbian Little and Desktop.

To reproduce
Just start with a fresh copy of Raspbian Lite or Desktop.

Expected behaviour
Raspberry should be able to use any type of monitor.

Actual behaviour
After starting up raspberry it blinks a few times then shows no signal and finally switches to power saving mode. No output from kernel buffer, nor frame buffer, nor X is visible. Upgrading to latest Raspbian version (together with firmware upgrade) doesn't fix this issue.

On the other side kmscube is able to initialize the display and renders colorful spinning cube.

I've manage to get kernel buffer working on Raspbian Little by editing /boot/config.txt and setting:

hdmi_group=2
hdmi_mode=16

it also works with hdmi_mode=39 and hdmi_mode=81, but still X server is showing nothing.

Finally after stopping adding xrandr --output HDM-1 --mode 1360x768 to /root/.xsessionrc, then stopping lightdm and executing startx I'm able to see window manager.

All of the above I need to do over ssh, since I can only see a black screen on Pi.

System
Here is my raspinfo.txt

Additional context
I'm mostly interested in running flutter-pi on my Pi 4, which (I assume) uses direct access to DRI, more context about this issue can be found here ardera/flutter-pi#16

[carlonluca]

I had other issues with a display with that resolution: #3221. Maybe related?

[popcornmix]

That resolution is a known issue. See: https://forums.raspberrypi.com/viewtopic.php?t=284866

The 2711 hardware cannot support odd horizontal blanking timings.

The kms driver should filter out that resolution which normally means it falls back to 1080p or 720p.

It may be possible to drive 1366x768 using custom timings (with even blanking periods), but there's no way to be sure if display will accept that.

But there's nothing more we can do as it's a hardware issue.