CentOS - Jan 2024 - no video with Aspeed (ast module) and latest kernel

Hello,
I have a CentOS Stream 9 server.
It is an Intel D50DNP1SBB one with:

02:00.0 VGA compatible controller: ASPEED Technology, Inc. ASPEED Graphics
Family (rev 52) (prog-if 00 [VGA controller])
        DeviceName: ASPEED AST2600
        Subsystem: ASPEED Technology, Inc. ASPEED Graphics Family
        Flags: medium devsel, IRQ 16, NUMA node 0, IOMMU group 42
        Memory at 94000000 (32-bit, non-prefetchable) [size=16M]
        Memory at 95000000 (32-bit, non-prefetchable) [size=256K]
        I/O ports at 1000 [size=128]
        Capabilities: [40] Power Management version 3
        Capabilities: [50] MSI: Enable- Count=1/4 Maskable- 64bit+
        Kernel driver in use: ast
        Kernel modules: ast

Under kernel 5.14.0-386.el9.x86_64 I'm able to connect via bmc without any
problem both in text mode (multi-user.target) and graphical
(graphical.target).
Both with and without Wayland enabled in /etc/gdm/custom.conf

This morning I updated the system and the kernel is now
5.14.0-404.el9.x86_64, and I'm not able to see the console in any of the 3
configurations above in my bmc kvm remote terminal. Ssh connection to the
system is ok without problem.
Inside the remote kvm console I see the grub menu, I see the scrolling
kernel boot sequence (I removed rhgb quiet options), but at the end my
remote kvm display square disappears.
How can I debug? Can I disable DRM for the ast kernel module? or start with
vesa in any way?

screenshot with 5.14.0-386.el9.x86_6:
https://drive.google.com/file/d/1VoDYAYLOIrErOGVNXgR8wNypzxyjd7k8/view?usp=sharing

screenshot with 5.14.0-404.el9.x86_64:
https://drive.google.com/file/d/1UClBOXHIjxc4rqiKW0wbMwIYKlrB_kGn/view?usp=sharing

Thanks in advance,
Gianluca

On Wed, Jan 10, 2024 at 5:15?PM Gianluca Cecchi <gianluca.cecchi at
gmail.com>
wrote:
> Hello,
> I have a CentOS Stream 9 server.
> It is an Intel D50DNP1SBB one with:
>
> 02:00.0 VGA compatible controller: ASPEED Technology, Inc. ASPEED Graphics
> Family (rev 52) (prog-if 00 [VGA controller])
>         DeviceName: ASPEED AST2600
>         Subsystem: ASPEED Technology, Inc. ASPEED Graphics Family
>         Flags: medium devsel, IRQ 16, NUMA node 0, IOMMU group 42
>         Memory at 94000000 (32-bit, non-prefetchable) [size=16M]
>         Memory at 95000000 (32-bit, non-prefetchable) [size=256K]
>         I/O ports at 1000 [size=128]
>         Capabilities: [40] Power Management version 3
>         Capabilities: [50] MSI: Enable- Count=1/4 Maskable- 64bit+
>         Kernel driver in use: ast
>         Kernel modules: ast
>
> Under kernel 5.14.0-386.el9.x86_64 I'm able to connect via bmc without
any
> problem both in text mode (multi-user.target) and graphical
> (graphical.target).
> Both with and without Wayland enabled in /etc/gdm/custom.conf
>
> This morning I updated the system and the kernel is now
> 5.14.0-404.el9.x86_64, and I'm not able to see the console in any of
the 3
> configurations above in my bmc kvm remote terminal. Ssh connection to the
> system is ok without problem.
>
solved addin at the end of GRUB_CMDLINE_LINUX line in /etc/default/grub
rdblacklist=ast ast.modeset=0
and then
grub2-mkconfig -o /boot/efi/EFI/centos/grub.cfg
reboot
Gianluca