[Intel-gfx] [PATCH 4/6] drm/i915: enable VT switchless resume v2

[Daniel Vetter]

On Mon, Mar 18, 2013 at 6:42 PM, Jesse Barnes <jbarnes at virtuousgeek.org> wrote:
> On Mon, 18 Mar 2013 08:49:07 +0100
> Daniel Vetter <daniel at 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 at 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.

Hm, where do we do that currently? Without fbcon I don't see it, and
we can't really rely on userspace to get this right I guess ...

> 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.

That just reminded me that we also should restore the right dpms state
I think. At least I'm not too sure whether we'll currently do that
(and whether the modeset state tracker would catch it). Otoh dpms
standby/suspend died with gen4 ;-)
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch