Re: MGA G200 issue in 6.12 and up

From: Wakko Warner
Date: Mon Apr 14 2025 - 20:35:42 EST


I found the fix that works for me. See below.

Wakko Warner wrote:
> I decided to upgrade to 6.14 on a system with a Matrox G200 onboard vga
> (supermicro X9SCL).
>
> I use this system via the BMC. When the mgag200 driver loads, the bmc
> screen flashes between no signal and the screen. The rate seems to be about
> 1 second no signal and 1 second with signal.
>
> 6.12 and 6.13 both have this problem.
>
> 6.11 does not have this problem.
>
> I have a monitor plugged into the vga port and it doesn't have this problem
> on any of the kernels I've tried. Only the remote connection through the bmc
> has this problem. I have booted the system with and with out the monitor
> plugged in, it does not appear to make a difference.

I found a thread on arch linux forums
(https://bbs.archlinux.org/viewtopic.php?id=303819) where the op has the
same issue. He bisected and came up with the bad commit.
That commit is
d6460bd52c27fde97d6a73e3d9c7a8d747fbaa3e drm/mgag200: Add dedicated variables
for blanking fields

I searched this commit and manually reverted it from my vanilla 6.14 and it
works fine. No blinking in the BMC remote console and the external VGA
works fine as well.

--
Microsoft has beaten Volkswagen's world record. Volkswagen only created 22
million bugs.