Add a reset interface

[Chris Wilson]

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?

(Poking since this fixes a regression in .38.)

Thanks,
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre