Re: [PATCH 2/2] drm/imx: ipuv3-plane: support underlay plane

[Michael Tretter <m.tretter@pengutronix.de>]

On Mon, 16 Feb 2026 14:18:41 +0100, Philipp Zabel wrote:
> On Mo, 2026-02-16 at 13:44 +0100, Michael Tretter wrote:
> > The IPUv3 overlay plane may be placed over or under the primary plane.
> > Use an immutable position of 1 for the primary plane and a mutable
> > position including 0 and 2 for the overlay plane, to allow placing the
> > overlay plane over and under the primary plane.
> > 
> > Signed-off-by: Michael Tretter <m.tretter@pengutronix.de>
> > ---
> >  drivers/gpu/drm/imx/ipuv3/ipuv3-plane.c | 12 +++++++-----
> >  1 file changed, 7 insertions(+), 5 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/imx/ipuv3/ipuv3-plane.c b/drivers/gpu/drm/imx/ipuv3/ipuv3-plane.c
> > index dfd036f3195e..ddad5ea92aad 100644
> > --- a/drivers/gpu/drm/imx/ipuv3/ipuv3-plane.c
> > +++ b/drivers/gpu/drm/imx/ipuv3/ipuv3-plane.c
> > @@ -890,7 +890,7 @@ struct ipu_plane *ipu_plane_init(struct drm_device *dev, struct ipu_soc *ipu,
> >  {
> >  	struct ipu_plane *ipu_plane;
> >  	const uint64_t *modifiers = ipu_format_modifiers;
> > -	unsigned int zpos = (type == DRM_PLANE_TYPE_PRIMARY) ? 0 : 1;
> > +	unsigned int primary_zpos = 1;
> >  	unsigned int format_count;
> >  	const uint32_t *formats;
> >  	int ret;
> > @@ -928,12 +928,14 @@ struct ipu_plane *ipu_plane_init(struct drm_device *dev, struct ipu_soc *ipu,
> >  	else
> >  		drm_plane_helper_add(&ipu_plane->base, &ipu_plane_helper_funcs);
> >  
> > -	if (dp == IPU_DP_FLOW_SYNC_BG || dp == IPU_DP_FLOW_SYNC_FG)
> > -		ret = drm_plane_create_zpos_property(&ipu_plane->base, zpos, 0,
> > -						     1);
> > +	if ((dp == IPU_DP_FLOW_SYNC_BG || dp == IPU_DP_FLOW_SYNC_FG) &&
> 
> These checks is not necessary anymore. The only overlay plane is (dp ==
> IPU_DP_FLOW_SYNC_FG).

Thanks! That's even better. I'll simplify the check in v2.

Michael