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

On Mon, 16 Feb 2026 14:18:41 +0100, Philipp Zabel wrote:

On Mo, 2026-02-16 at 13:44 +0100, Michael Tretter wrote:

quoted

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