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

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