[Intel-gfx] [PATCH 3/8] drm/i915: Unconditionally clear plane visibility, v2.

[Ville Syrjälä]

On Fri, Sep 21, 2018 at 06:00:27PM +0200, Maarten Lankhorst wrote:
> Op 21-09-18 om 17:26 schreef Ville Syrjälä:
> > On Thu, Sep 20, 2018 at 12:27:06PM +0200, Maarten Lankhorst wrote:
> >> We need to assume the plane has been visible before, even if no CRTC
> >> is assigned to the plane. This is because nv12 will enable a a extra
> >> plane and make it visible by marking it in crtc_state->active_planes
> >> for intel_update_planes_on_crtc().
> >>
> >> Additionally, clear visible flag in intel_plane_atomic_check, in case
> >> we ever hit a bug with visibility. Our code implicitly assumes that
> >> plane_state->visible is only true when crtc and fb are set,
> >> so we will either null deref in intel_fbc_choose_crtc() or
> >> do something bad during the actual commit which cares even more.
> >>
> >> Changes since v1:
> >> - Unconditionally clear crtc_state->active_planes as well.
> >> - Reword commit message, since this is now a preparation patch for
> >>   NV12 Y / UV plane linking.
> >>
> >> Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> >> ---
> >>  drivers/gpu/drm/i915/intel_atomic_plane.c | 8 +++++---
> >>  1 file changed, 5 insertions(+), 3 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/i915/intel_atomic_plane.c b/drivers/gpu/drm/i915/intel_atomic_plane.c
> >> index aabebe0d2e9b..f70e9cb9cf02 100644
> >> --- a/drivers/gpu/drm/i915/intel_atomic_plane.c
> >> +++ b/drivers/gpu/drm/i915/intel_atomic_plane.c
> >> @@ -117,10 +117,13 @@ int intel_plane_atomic_check_with_state(const struct intel_crtc_state *old_crtc_
> >>  	struct intel_plane *intel_plane = to_intel_plane(plane);
> >>  	int ret;
> >>  
> >> +	crtc_state->active_planes &= ~BIT(intel_plane->id);
> > nv12_planes too?
> No, we don't have to. We don't set nv12_planes on the Y plane. :)
> In all other cases we clear it correctly.

I think sticking to single approach would be less confusing nonetheless.

-- 
Ville Syrjälä
Intel