Re: [PATCH 2/8] drm/fb-helper: Add support for DRM_FORMAT_C[124]

Sam Ravnborg
2022-02-17T20:34:47Z

Hi Geert,

> > > + switch (fb->format->depth) {
> >
> > The depth field is deprecated. It's probably better to use
> > fb->format->format and test against 4CC codes.
>
> The reason I checked for depth instead of a 4CC code is that the only
> thing that matters here is the number of bits per pixel. Hence this
> function won't need any changes to support R1, R2, R4, and D1 later.
> When we get here, we already know that we are using a format that
> is supported by the fbdev helper code, and thus passed the 4CC
> checks elsewhere.
>
> Alternatively, we could introduce drm_format_info_bpp() earlier in
> the series, and use that?

The drm_format_info_bpp() is very descriptive, so yes it would be good to use
it here also.

Sam