Re: [PATCH v3 0/5] Fix some race conditions that exists between fbmem and sysfb

[Javier Martinez Canillas]

Hello Daniel,

On 4/29/22 09:47, Daniel Vetter wrote:

[snip]

>>
>> Exactly, should be done when the device is registered rather than when
>> the driver is registered or a call is made to remove the conflicting FB.
>>
>> I'll rework this series with only the bits for sysfb_disable() and drop
>> the rest. We can go back to the discussion of the remaining parts later
>> if that makes sense (I still think that patch 3/5 is a better approach,
>> but let's defer that for a different series).
> 
> We need to kill sysfb _before_ the driver loads, otherwise you can have
> two drivers fighting over each another. And yes that means you might end
> up with black screen if the driver load goes wrong, but the two drivers
> fighting over each another can also result in black screens. And the
> latter isn't fixable any other way (in general at least) than by making
> sure the fw stuff is gone before driver load starts in earnest.

Yes, you are correct. I didn't realize all the possible cases when agreed
with Thomas about doing this but tried and found that it's not enough.

I've a full patch-set now and will post as a RFC so we can discuss more.

> -Daniel

-- 
Best regards,

Javier Martinez Canillas
Linux Engineering
Red Hat