drm/msm/dpu: do not limit the zpos property

Stop limiting zpos property values, we use normalized_zpos anyway. And
nothing stops userspace from assigning several planes to a single zpos
(it is a userspace bug, but the kernel is forgiving about it).
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Patchwork: https://patchwork.freedesktop.org/patch/473147/
Link: https://lore.kernel.org/r/20220209172520.3719906-3-dmitry.baryshkov@linaro.orgSigned-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>

drivers/gpu/drm/msm/disp/dpu1/dpu_plane.c

@@ -1478,7 +1478,6 @@ struct drm_plane *dpu_plane_init(struct drm_device *dev,
 	struct dpu_plane *pdpu;
 	struct msm_drm_private *priv = dev->dev_private;
 	struct dpu_kms *kms = to_dpu_kms(priv->kms);
-	int zpos_max = DPU_ZPOS_MAX;
 	uint32_t num_formats;
 	uint32_t supported_rotations;
 	int ret = -EINVAL;
@@ -1517,14 +1516,7 @@ struct drm_plane *dpu_plane_init(struct drm_device *dev,
 
 	pdpu->catalog = kms->catalog;
 
-	if (kms->catalog->mixer_count &&
-		kms->catalog->mixer[0].sblk->maxblendstages) {
-		zpos_max = kms->catalog->mixer[0].sblk->maxblendstages - 1;
-		if (zpos_max > DPU_STAGE_MAX - DPU_STAGE_0 - 1)
-			zpos_max = DPU_STAGE_MAX - DPU_STAGE_0 - 1;
-	}
-
-	ret = drm_plane_create_zpos_property(plane, 0, 0, zpos_max);
+	ret = drm_plane_create_zpos_property(plane, 0, 0, DPU_ZPOS_MAX);
 	if (ret)
 		DPU_ERROR("failed to install zpos property, rc = %d\n", ret);