[Intel-gfx] [PATCH 6/8] drm/i915: Wrap the preallocated BIOS framebuffer and preserve for KMS fbcon v7

[Daniel Vetter]

On Tue, Dec 17, 2013 at 11:51 PM, Chris Wilson <chris at chris-wilson.co.uk> wrote:
> On Tue, Dec 17, 2013 at 10:58:51PM +0100, Daniel Vetter wrote:
>> On Tue, Dec 17, 2013 at 10:30 PM, Jesse Barnes <jbarnes at virtuousgeek.org> wrote:
>> > So in the unlikely event that the fb helper code fails I don't want to
>> > fall over.
>> >
>> > But that shouldn't happen in practice.  I only have the checks in place
>> > to catch when I failed to set the fbdev field in one path (which is now
>> > fixed)
>>
>> Imo if a core piece of the driver fails to initialize we should just
>> fail driver loading. We've had tons of crazy lore around contexts
>> failing, ppgtt failing and other similar stuff, and I think it just
>> makes the normal code more fragile with no real gain.
>>
>> If you think something slips through the cracks maybe just throw a
>> BUG_ON in there instead.
>
> I tripped over it earlier when I was disabling parts of the driver.
> I think allowing dev_priv->fbdev to be NULL fits nicely with your
> crusade against fbcon.
> (In fact it was quite fun to load the driver without modesetting as a
> headless accelerator...)

Well for fully disabled fbdev we nuke all those functions completely.
If we want to go with this safety net here then I think at least a
WARN_ON or something should be put in there, since this really
shouldn't happen.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch