[Intel-gfx] [PATCH] drm/i915: re-init modeset hw state after gpu reset

[Chris Wilson]

On Tue, 10 Apr 2012 15:50:11 +0200, Daniel Vetter <daniel.vetter at ffwll.ch> wrote:
> After a gpu reset we need to re-init some of the hw state we only
> initialize when modeset is enabled, like rc6, hw contexts or render/GT
> core clock gating and workaround register settings.
> 
> Note that this patch has a small change in the resume code:
> - rc6 on gen6+ is only restored for the modeset case (for more
>   consistency with other callsites). This is no problem because recent
>   kernels refuse to load drm/i915 without kms on gen6+
> - rc6/emon on ilk is only restored for the modeset case. This is no
>   problem because rc6 is disabled by default on ilk, and ums on ilk
>   has never really been a supported option outside of horrible rhel
>   backports.
> 
> v2: Chris Wilson noticed that we not only fail to restore the clock
> gating settings after gpu reset.
> 
> v3: Move the call to modeset_init_hw in _reset out of the
> struct_mutext protected area - other callers don't hold it, too.
> 
> Signed-Off-by: Daniel Vetter <daniel.vetter at ffwll.ch>

I don't think it makes the locking any worse than it already is, but it
is becoming more and more suspect.

Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre