Add a reset interface

[Dave Airlie]

On Sun, Jan 30, 2011 at 9:50 PM, Chris Wilson <chris at chris-wilson.co.uk> wrote:
> On Mon, 24 Jan 2011 15:55:27 +0000, Chris Wilson <chris at chris-wilson.co.uk> wrote:
>> For i915 there is a need to invalidate some cached state after resuming or
>> reseting the GPU. This is not quite the same as simply restoring saved
>> state (i.e. the standard suspend resume method), so do not seem to merit
>> reusing the save|restore vfuncs.  Instead I propose a
>>
>>    drm_mode_config_reset(struct drm_device *);
>>
>> routine to iterate over all the attached CRTCs, encoders and connectors
>> and call any supplied reset vfunc.
>>
>> This is required to fix some modesetting regressions across resume in
>> 2.6.38:
>> https://bugzilla.kernel.org/show_bug.cgi?id=26952
>> https://bugzilla.kernel.org/show_bug.cgi?id=27272
>
> Dave, what's your take on adding a new (crtc|encoder|connector)->reset()
> vfunc to drm core? Do I need to code up an Intel specific alternative?

It seems like an interface we could use, I just wasn't sure how a regression fix
for something in. 38 isn't a revert but requires a whole new interface
in the core
drm to fix. Perhaps if you can enlighten me on that I'd be happier.

Dave.