[PATCH] drm/arm/hdlcd: Take over EFI framebuffer properly

[Thomas Zimmermann]

Am 15.06.22 um 09:50 schrieb Javier Martinez Canillas:
[...]
>> Historically, most drivers call this function very early. But for error
>> recovery it would be better to do it as late as possible.  Ideally,
>> drivers would first initialize their DRM software state, then kickout
>> the generic driver, and finally take over hardware. But that would
>> require a careful review of each driver. :/
>>
> 
> We got bug reports on Fedora about regressions caused by the fact that some
> programs made the (wrong) assumption that /dev/dri/card0 would be the "main"
> display and just hard-coded that path.

Shh! Don't tell anyone.

> 
> But removing the conflicting framebuffers after calling devm_drm_dev_alloc()
> breaks this assumption, since the registered device will be /dev/dri/card1.
> 
> All this is to say that doing it too late, even if nothing is touching the HW
> yet, could still have unexpected consequences across your graphics stack.
> 

-- 
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Ivo Totev
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