Re: [Intel-xe] [PATCH 08/10] fixup! drm/xe/display: Implement display support

[Jani Nikula <jani.nikula@intel.com>]

On Wed, 04 Oct 2023, Lucas De Marchi <lucas.demarchi@intel.com> wrote:
> On Tue, Oct 03, 2023 at 05:34:55PM +0300, Jani Nikula wrote:
>>Turn the enable_display module parameter to the same thing as it is for
>>i915: assuming you have display hardware, take over it, put it to sleep,
>>and keep connectors disconnected.
>
> that was not what it was created for and it was on purpose. That is not
> what we need when enabling a platform. The argument that *users* would
> then be left in a situation that the display hardware is still consuming
> power is IMO wrong as those *users* are not supposed to be using module
> parameters and if they do, it's their only responsibility.
>
> The module parameter here is for kernel developers and CI/validation,
> particularly when enabling a new platform, to decide if the display side
> should be enabled or not.

If you have a module param without the _unsafe annotation, and the only
documentation is "enable display", it *is* for users.

If you want to have a module param that's for development or debugging
only, make it _unsafe, and add documentation to that effect.

In any case, what's currently in the tree is conflated and broken, and
this is/was an attempt to fix it. It's impossible to integrate xe with
i915 display if the xe has different notions on the basic idea of what
having or enabling display means.

BR,
Jani.

-- 
Jani Nikula, Intel