Re: [PATCH 4/6] drm/i915: enable VT switchless resume v2

[Jesse Barnes <jbarnes@virtuousgeek.org>]

On Mon, 18 Mar 2013 08:49:07 +0100
Daniel Vetter <daniel@ffwll.ch> wrote:

> On Tue, Feb 19, 2013 at 12:11:41PM -0800, Jesse Barnes wrote:
> > With the other bits in place, we can do this safely.
> > 
> > v2: disable backlight on suspend to prevent premature enablement on resume
> > 
> > Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
> > ---
> >  drivers/gpu/drm/i915/i915_drv.c |   12 +++++++++---
> >  drivers/gpu/drm/i915/intel_fb.c |    3 +++
> >  2 files changed, 12 insertions(+), 3 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> > index c5b8c81..e76b038 100644
> > --- a/drivers/gpu/drm/i915/i915_drv.c
> > +++ b/drivers/gpu/drm/i915/i915_drv.c
> > @@ -492,9 +492,10 @@ static int i915_drm_freeze(struct drm_device *dev)
> >  
> >  		cancel_delayed_work_sync(&dev_priv->rps.delayed_resume_work);
> >  
> > -		intel_modeset_disable(dev);
> 
> As discussed in person last week, simply dropping this will probably kill
> S0i3 support.

Not really, since DPMS will be off in that case too generally, but it
does make testing harder.

I think it just needs to be a low level call to crtc disable on each
pipe, otherwise we'll zap the state we're trying to save.

-- 
Jesse Barnes, Intel Open Source Technology Center