Re: Trying to start Xorg on a vanilla bullseye on rpi4

[Tim Woodall <debianuser@woodall.me.uk>]

On Thu, 3 Nov 2022, Tim Woodall wrote:

> On Thu, 3 Nov 2022, Andrew M.A. Cater wrote:
>
> > On Thu, Nov 03, 2022 at 06:12:56PM +0000, Tim Woodall wrote:
> > > Hi,
> > >
> > > I have a vanilla installation of debian bullseye on a rpi4
> >
> > Just going to check: this is a Debian image from gwolf and 
> > https://raspi.debian.net/ and not a Raspberry Pi OS image from Raspberry Pi 
> > foundation?
> It's a home built image but only with stock debian packages installed. I
> don't believe those images have X setup, but if they do then I'll try
> one which might give me a clue what I've done wrong.
>
> > The image is 32 bit or 64 bit?
> 64 bit

I've tried updating the kernel to bullseye-backports but that hasn't
helped.

It's using the modesetting driver. Putting nomodeset on the kernel
commandline and that doesn't work.

Forcing X11 to use the fbdev device does start but doesn't find any
outputs.

If I set the output of the second monitor to 1920x1080 I can move it
around the 4K first monitor

The following is enough to get Xorg to start with two screens connected:

Section "Screen"
    Identifier "Screen 0"
    SubSection "Display"
        Virtual 3840 2160
    EndSubSection
EndSection

Setting the Virtual to anything bigger and Xorg fails to start.

I don't know how to create two device sections - this doesn't work:

Section "Device"
    Identifier "vc4-0"
    Driver "modesetting"
    Screen 0
EndSection

Section "Device"
    Identifier "vc4-1"
    Driver "modesetting"
    Screen 1
EndSection

I'm not sure what I should put for BusId - it doesn't show up in lspci

This fails with:
(EE) 
Fatal server error:
(EE) no screens found(EE) 
(EE)

adding BusID "card0" and I get:
(EE) 
Fatal server error:
(EE) Cannot run in framebuffer mode. Please specify busIDs        for all framebuffer devices
(EE)