[PATCH 02/14] drm/exynos: Remove exynos_plane_dpms() call with no effect

[Daniel Vetter]

On Wed, Feb 04, 2015 at 04:42:57PM +0900, Joonyoung Shim wrote:
> Hi,
> 
> On 02/04/2015 04:14 AM, Gustavo Padovan wrote:
> > From: Gustavo Padovan <gustavo.padovan at collabora.co.uk>
> > 
> > exynos_plane_dpms(DRM_MODE_DPMS_ON) calls the win_enable()'s callback
> > from the underlying layer. However neither one of these layers implement
> > win_enable() - FIMD, Mixer and VIDI. Thus the call to exynos_plane_dpms()
> > is pointless.
> > 
> > Signed-off-by: Gustavo Padovan <gustavo.padovan at collabora.co.uk>
> > ---
> >  drivers/gpu/drm/exynos/exynos_drm_crtc.c | 2 --
> >  1 file changed, 2 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/exynos/exynos_drm_crtc.c b/drivers/gpu/drm/exynos/exynos_drm_crtc.c
> > index b2a4b84..ad675fb 100644
> > --- a/drivers/gpu/drm/exynos/exynos_drm_crtc.c
> > +++ b/drivers/gpu/drm/exynos/exynos_drm_crtc.c
> > @@ -65,8 +65,6 @@ static void exynos_drm_crtc_commit(struct drm_crtc *crtc)
> >  
> >  	if (exynos_crtc->ops->commit)
> >  		exynos_crtc->ops->commit(exynos_crtc);
> > -
> > -	exynos_plane_dpms(crtc->primary, DRM_MODE_DPMS_ON);
> 
> As i said, this needs to keep pair enabled flag of struct
> exynos_drm_plane.

The reason exynos needs that exynos_plane->enable is because it has its
own per-plane dpms state. There's two problems with that:
- It's highyl non-standard, the drm kms way is to just disable the plane
  and not have some additional knob on top.
- The atomic helpers will not be able to handle this. They assume that
  there's only one dpms knob for the entire display pipeline, and
  per-plane enable/disable is handled by setting plane->state->crtc, which
  must be set iff plane->state->fb is set right now.

I recommend we rip this all out if we can adjust existing userspace to
stop using the "mode" property on planes and crtcs.

And with that non-standard exynos plane mode thing gone we can indeed rip
out exynos_plane_dpms and exynos_plane->enabled and just directly call
manager->ops->win_enable/disble. And then rip out the win_enable since
it's unused.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch