Hi
Am 13.02.25 um 14:33 schrieb Jocelyn Falempe:
Hi Thomas and Jammy,
I've got a regression report, and it's caused by
https://patchwork.freedesktop.org/patch/540015/
On this ast2600 server, the firmware says it has a DP output, but
physically, there is only one VGA output.
Before this commit, "ast->tx_chip_types |= BIT(AST_TX_ASTDP)" means it
will have both VGA and DP configured, but after this changed to
"ast->tx_chip_types = AST_TX_ASTDP_BIT" and the VGA connector disappear.
Having multiple outputs (besides the virtual BMC) was never really
supported. DRM userspace also doesn't really support it. You likely
remember that we had problems when the BMC was a separate output.
The EDID of the VGA monitor is not read anymore, and a wrong
resolution is setup causing a blank screen.
Of course fixing the firmware would be the best solution, it's not
always possible.
I'm considering different options:
- Add a kernel module parameter to override the tx_chip_types,
something like "ast.output=vga"
No parameters please. If we give people parameters, they will configure
the hell out of them and then complain if it doesn't work. And we never
get rid of parameters, because "there's users".
- Add a DMI quirk, to force vga on this particular motherboard.
That could work.
What do you think?
I think I saw another bit in the HW docs that hints towards a VGA
output, but I cannot find it anymore. Still, I have VGA and DP on my
test board. There's gotta be a way of switching between them.
Unless something else shows up, let's to the DMI quirk. It should also
be easy to backport.
Best regards
Thomas
Best regards,
--
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman
HRB 36809 (AG Nuernberg)
