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

From: Javier Martinez Canillas
Date: Mon May 02 2022 - 13:15:57 EST


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]:

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

--
Best regards,

Javier Martinez Canillas
Linux Engineering
Red Hat