Re: [PATCH v2 1/3] drm: Remove superfluous arg when calling to drm_fbdev_generic_setup()

From: Laurent Pinchart
Date: Mon May 02 2022 - 14:36:55 EST


On Mon, May 02, 2022 at 07:15:16PM +0200, Javier Martinez Canillas wrote:
> On 5/2/22 18:55, Javier Martinez Canillas wrote:
>
> [snip]
>
> >> drop the depth option to drm_fbdev_generic_setup() ? There's a FIXME
> >> comment in drm_fbdev_generic_setup() that could be related.
> >
> > A FIXME makes sense, I'll add that to when posting a v3.
>
> There's actually a FIXME already in drm_fbdev_generic_setup(), so it's
> a documented issue [0]:

That's what I meant by "there's a FIXME" :-) It doesn't have to be
addressed by this series, but it would be good to fix it.

> void drm_fbdev_generic_setup(struct drm_device *dev,
> unsigned int preferred_bpp)
> {
> ...
> /*
> * FIXME: This mixes up depth with bpp, which results in a glorious
> * mess, resulting in some drivers picking wrong fbdev defaults and
> * others wrong preferred_depth defaults.
> */
> if (!preferred_bpp)
> preferred_bpp = dev->mode_config.preferred_depth;
> if (!preferred_bpp)
> preferred_bpp = 32;
> fb_helper->preferred_bpp = preferred_bpp;
> ...
> }
>
> [0]: https://elixir.bootlin.com/linux/v5.18-rc5/source/drivers/gpu/drm/drm_fb_helper.c#L2553

--
Regards,

Laurent Pinchart