Re: [PATCH 2/2] drm: Move crtc->{x, y, mode, enabled} to legacy sub-structure

[Louis Chauvet <louis.chauvet@xxxxxxxxxxx>]

> > > diff --git a/drivers/gpu/drm/vkms/vkms_crtc.c 
> > > b/drivers/gpu/drm/vkms/vkms_crtc.c
> > > index a40295c18b48..780681ea77e4 100644
> > > --- a/drivers/gpu/drm/vkms/vkms_crtc.c
> > > +++ b/drivers/gpu/drm/vkms/vkms_crtc.c
> > > @@ -64,7 +64,7 @@ static int vkms_enable_vblank(struct drm_crtc *crtc)
> > >   struct drm_vblank_crtc *vblank = drm_crtc_vblank_crtc(crtc);
> > >   struct vkms_output *out = drm_crtc_to_vkms_output(crtc);
> > >  
> > > - drm_calc_timestamping_constants(crtc, &crtc->mode);
> > > + drm_calc_timestamping_constants(crtc, &crtc->legacy.mode);
> > 
> >     drm_calc_timestamping_constants(crtc, &crtc->state->mode);
> 
> This one doesn't look safe. You want to call that during your atomic
> commit already.
> 

This was already not safe with the previous implementation? Or it is only 
unsafe because now I use state->mode instead of legacy.mode?

After inspecting the code, I think I don't need to call it as:

In `vkms_atomic_commit_tail` (used in 
`@vkms_mode_config_helpers.atomic_commit_tail`), we call 
`drm_atomic_helper_commit_modeset_disables`, which call 
`drm_atomic_helper_calc_timestamping_constants` which call 
`drm_calc_timestamping_constants` for every CRTC.

I tested kms_vblank, all of them are SUCCESS/SKIP, do you know other tests 
that can trigger bugs?

-- 
Louis Chauvet, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com