[PATCH v2 5/8] drm/atomic: Call drm_atomic_helper_fake_vblank() from the generic commit_tail() helpers

[Boris Brezillon]

On Mon, 2 Jul 2018 09:57:30 +0200
Daniel Vetter <daniel at ffwll.ch> wrote:

> On Mon, Jul 02, 2018 at 09:54:32AM +0200, Daniel Vetter wrote:
> > On Fri, Jun 29, 2018 at 01:17:18PM +0200, Boris Brezillon wrote:  
> > > Now that we have a way to fake VBLANK events when requested by the CRTC
> > > hook it up to the generic commit_tail() helpers.
> > > 
> > > Signed-off-by: Boris Brezillon <boris.brezillon at bootlin.com>  
> > 
> > I really don't like this. We've had epic amounts of bugs with atomic
> > drivers failing to send out vblank events when they should, and I added a
> > bunch of debug checks to make sure that doesn't happen anymore.
> > 
> > Now there's no way anymore for drivers to spot this until they have
> > misrenderings on wayland and no idea why. Imo this should only be used by
> > specific drivers, with a comment why exactly they need it.  
> 
> Meh I retract, you have the special no_vblank state flag to control this.
> Looks all good to me.

Hehe, just replied to your other email :-).

> 
> Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> 
> > -Daniel
> >   
> > > ---
> > >  drivers/gpu/drm/drm_atomic_helper.c | 4 ++++
> > >  1 file changed, 4 insertions(+)
> > > 
> > > diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
> > > index ca586993c2a2..1a088462bc42 100644
> > > --- a/drivers/gpu/drm/drm_atomic_helper.c
> > > +++ b/drivers/gpu/drm/drm_atomic_helper.c
> > > @@ -1448,6 +1448,8 @@ void drm_atomic_helper_commit_tail(struct drm_atomic_state *old_state)
> > >  
> > >  	drm_atomic_helper_commit_modeset_enables(dev, old_state);
> > >  
> > > +	drm_atomic_helper_fake_vblank(old_state);
> > > +
> > >  	drm_atomic_helper_commit_hw_done(old_state);
> > >  
> > >  	drm_atomic_helper_wait_for_vblanks(dev, old_state);
> > > @@ -1477,6 +1479,8 @@ void drm_atomic_helper_commit_tail_rpm(struct drm_atomic_state *old_state)
> > >  	drm_atomic_helper_commit_planes(dev, old_state,
> > >  					DRM_PLANE_COMMIT_ACTIVE_ONLY);
> > >  
> > > +	drm_atomic_helper_fake_vblank(old_state);
> > > +
> > >  	drm_atomic_helper_commit_hw_done(old_state);
> > >  
> > >  	drm_atomic_helper_wait_for_vblanks(dev, old_state);
> > > -- 
> > > 2.14.1
> > >   
> > 
> > -- 
> > Daniel Vetter
> > Software Engineer, Intel Corporation
> > http://blog.ffwll.ch  
>