[PATCH] drm/fb-helper: Add TODO for making drm_fb_helper_alloc_fbi fill apertures

[Hans de Goede]

Hi,

On 3/26/20 6:55 PM, Daniel Vetter wrote:
> On Thu, Mar 26, 2020 at 4:10 PM Hans de Goede <hdegoede at redhat.com> wrote:
>>
>> Currently drivers using drm_fbdev_generic_setup() end up with a single
>> empty aperture in their fb_info struct.
>>
>> Not having the proper info in the apertures list causes
>> register_framebuffer to not remove conflicting framebuffers,
>> which some drivers currently workaround by manually calling
>> drm_fb_helper_remove_conflicting_pci_framebuffers().
>>
>> Add a TODO as a reminder that we need to fix this.
>>
>> Signed-off-by: Hans de Goede <hdegoede at redhat.com>
>> ---
>>   drivers/gpu/drm/drm_fb_helper.c | 8 ++++++++
>>   1 file changed, 8 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
>> index 4c7cbce7bae7..16b8dc38d022 100644
>> --- a/drivers/gpu/drm/drm_fb_helper.c
>> +++ b/drivers/gpu/drm/drm_fb_helper.c
>> @@ -526,6 +526,14 @@ struct fb_info *drm_fb_helper_alloc_fbi(struct drm_fb_helper *fb_helper)
>>          if (ret)
>>                  goto err_release;
>>
>> +       /*
>> +        * TODO: We really should be smarter here and alloc an apperture
>> +        * for each IORESOURCE_MEM resource helper->dev->dev has and also
>> +        * init the ranges of the appertures based on the resources.
>> +        * Note some drivers currently count on there being only 1 empty
>> +        * aperture and fill this themselves, these will need to be dealt
>> +        * with somehow when fixing this.
>> +        */
> 
> Ah yes this is a bit more involved than first apperances suggest - we
> might want to have a dedicated solution for the generic_setup helper
> only, so we don't break all the other drivers using this function
> directly.
> 
> Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>

Thank you, pushed to drm-misc-next.

Any chance you can perhaps take (another) look at:
https://patchwork.freedesktop.org/patch/340140/

? We had an interesting discussion about that which
seems (to me) to end in agreement and you asking for
more documentation. I replied to that that the patch
already added some (but not much) documentation and
then the discussion ended. I would still like to get
this patch upstream, as I have a userspace patch
(for plymouth) pending which depends on it.

Regards,

Hans