Re: drm/vc4: module dysfunctional on Raspberry Pi 3B as of 5.18.0

[Peter Robinson <pbrobinson@gmail.com>]

Hi Maxime,

> > > As of Linux 5.18.0, module vc4 apparently isn't working on Raspberry Pi
> > > 3B any more.
> > >
> > > If a monitor is attached to the device, the boot messages show up as
> > > usual, but right when KMS starts, the screen turns black. Similarly, the
> > > screen also turns black when the module is blacklisted at boot time and
> > > loaded from the running system.
> > > The problem looks quite similar to the one posted some months ago in [1].
>
> If I understand you properly, it results in a blank screen if the
> monitor is connected, but the system is still responsive?

Yes, it boots fine, I see all serial console output and the module
loads etc, without a screen I didn't notice the issue

> If so, it's a very different problem than the link you provided, since
> it was occurring when no monitor was connected and resulted in a total
> system hang.
>
> > > Unfortunately, looking through systemd's journal didn't seem to yield
> > > any real hint. Nevertheless, the results from grepping vc4 are
> >
> > I'm seeing the same issue with vc4 on a RPi3 on 5.18.1 on Fedora so
> > can confirm the regression. Maxime would know what might be up here?
>
> I tested on 5.18 on my 3B and it works well. Could you paste your kernel
> configuration and config.txt somewhere?

It boots with output on 5.17.13, and not on 5.18. The config is at the
following link (Fedora config). The config.txt is below.
https://pbrobinson.fedorapeople.org/config-5.18.2-201.fc36.armv7hl

===
# Raspberry Pi 2
[pi2]
kernel=rpi2-u-boot.bin
dtoverlay=upstream

# Raspberry Pi 3
[pi3]
kernel=rpi3-u-boot.bin
dtoverlay=upstream

# Raspberry Pi 4
[pi4]
kernel=rpi4-u-boot.bin
dtoverlay=upstream-pi4

# Default Fedora configs for all Raspberry Pi Revisions
[all]
# Enable UART
# Only enable UART if you're going to use it as it has speed implications
# Serial console is ttyS0 on RPi3 and ttyAMA0 on all other variants
# u-boot will auto detect serial and pass corrent options to kernel if enabled
# Speed details: https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=141195

# Terrible hack to work around U-Boot issues on most devices
enable_uart=1

# Early boot delay in the hope monitors are initialised enough to provide EDID
bootcode_delay=1

# We need this to be 32Mb to support VCHI services and drivers which use them
# but this isn't used by mainline VC4 driver so reduce to lowest supported value
# You need to set this to at least 80 for using the camera
gpu_mem=32

# Use eXtended firmware by default
start_x=1

# Stop the RPi turning on HDMI monitors on reboot
hdmi_ignore_cec_init=1

# New option to allow the firmware to load upstream dtb
# Will allow things like camera, touchscreen etc to work OOTB
upstream_kernel=1
===