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
On 5/2/22 20:36, Laurent Pinchart wrote:
> 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.
>
doh, I misread your original email. Yes, it's the same issue as you
said and something that I plan to look at some point as a follow-up.
I hope that we could just replace fbcon with a kms/systemd-consoled/foo
user-space implementation before fixing all the stuff in the DRM fbdev
emulation layer :)
--
Best regards,
Javier Martinez Canillas
Linux Engineering
Red Hat
On Mon, May 02, 2022 at 09:28:45PM +0200, Javier Martinez Canillas wrote:
> On 5/2/22 20:36, Laurent Pinchart wrote:
> > 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.
>
> doh, I misread your original email. Yes, it's the same issue as you
> said and something that I plan to look at some point as a follow-up.
>
> I hope that we could just replace fbcon with a kms/systemd-consoled/foo
> user-space implementation before fixing all the stuff in the DRM fbdev
> emulation layer :)
If you can do that, I'll provide champagne :-)
--
Regards,
Laurent Pinchart