Re: [PATCH 1/4] drm: Add an interface to reset the device

[Chris Wilson <chris@chris-wilson.co.uk>]

On Mon, 24 Jan 2011 12:08:29 -0500, Alex Deucher <alexdeucher@gmail.com> wrote:
> On Mon, Jan 24, 2011 at 10:55 AM, Chris Wilson <chris@chris-wilson.co.uk> wrote:
> > Iterate over the attached CRTCs, encoders and connectors and call the
> > supplied reset vfunc in order to reset any cached state back to unknown.
> > Useful after an invalidation event such as a GPU reset or resuming.
> >
> 
> Can't you just reprogram the modes at resume?  I guess it would help
> to see what you are actually doing with this hook.

I tried to show just how I intended to use during resume and resetting a
hung GPU, and there is also a similarity with boot up (which may share the
same code). In these 2 instances were the GPU state becomes inconsistent
with the state in the connectors/crtc and so we need to reset. (Not doing
so means that the mode programming on resume fails.)

There is a large semantic difference between restore and reset, and since
reset was useful outside of resume, I felt the need for an additional
interface.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre