Re: [RESEND PATCH 2/5] drm: Move nomodeset kernel parameter handler to the DRM subsystem

Javier Martinez Canillas
2021-11-03T13:09:13Z

Hello Jani,

On 11/3/21 13:56, Jani Nikula wrote:

[snip]

>>
>> +obj-y += drm_nomodeset.o
>
> This is a subtle functional change. With this, you'll always have
> __setup("nomodeset", text_mode) builtin and the parameter available. And
> using nomodeset will print out the pr_warn() splat from text_mode(). But
> removing nomodeset will have no impact if CONFIG_VGA_CONSOLE=n as that
> leads to vgacon_text_force() always returning false.
>

Yes, that's what I decided at the end to make it unconditional. That
way the same behaviour is preserved (even when only DRM drivers are
using the exported symbol).

> To not make functional changes, this should be:
>
> obj-$(CONFIG_VGA_CONSOLE) += drm_nomodeset.o
>

Right, that should work.

> Now, going with the cleanup in this series, maybe we should make the
> functional change, and break the connection to CONFIG_VGA_CONSOLE
> altogether, also in the header?
>
> (Maybe we'll also need a proxy drm kconfig option to only have
> drm_modeset.o builtin when CONFIG_DRM != n.)
>

See my other email. I believe the issue is drivers/gpu/drm always
being included even when CONFIG_DRM is not set.

Best regards, --
Javier Martinez Canillas
Linux Engineering
Red Hat