[PATCH] drm/amdgpu/dc: Pixel encoding DRM property and module parameter

[Alex Deucher]

On Tue, Sep 22, 2020 at 4:51 PM James Ettle <james at ettle.org.uk> wrote:
>
> On 22/09/2020 21:33, Alex Deucher wrote:
> >> +/**
> >> + * DOC: pixel_encoding (string)
> >> + * Specify the initial pixel encoding used by a connector.
> >> + */
> >> +static char amdgpu_pixel_encoding[MAX_INPUT];
> >> +MODULE_PARM_DESC(pixel_encoding, "Override pixel encoding");
> >> +module_param_string(pixel_encoding, amdgpu_pixel_encoding, sizeof(amdgpu_pixel_encoding), 0444);
> >
> > You can drop this part.  We don't need a module parameter if we have a
> > kms property.
> >
> > Alex
>
> OK, but is there then an alternative means of setting the pixel encoding to be used immediately on boot or when amdgpu loads? Also are there user tools other than xrandr to change a KMS property, for Wayland and console users?

You can force some things on the kernel command line, but I don't
recall whether that includes kms properties or not.  As for ways to
change properties, the KMS API provides a way.  those are exposed via
randr when using X.  When using wayland compositors, it depends on the
compositor.

Alex