drm/nouveau/kms/nv50-: create primary plane before overlay planes

zpos normalisation uses plane id to determine ordering for duplicate zpos
values, and we likely want to keep primary plane on the bottom here.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/dispnv50/head.c

@@ -480,7 +480,7 @@ nv50_head_create(struct drm_device *dev, int index)
 	struct nouveau_drm *drm = nouveau_drm(dev);
 	struct nv50_disp *disp = nv50_disp(dev);
 	struct nv50_head *head;
-	struct nv50_wndw *curs, *wndw;
+	struct nv50_wndw *base, *ovly, *curs;
 	struct drm_crtc *crtc;
 	int ret;
 
@@ -492,13 +492,13 @@ nv50_head_create(struct drm_device *dev, int index)
 	head->base.index = index;
 
 	if (disp->disp->object.oclass < GV100_DISP) {
-		ret = nv50_ovly_new(drm, head->base.index, &wndw);
-		ret = nv50_base_new(drm, head->base.index, &wndw);
+		ret = nv50_base_new(drm, head->base.index, &base);
+		ret = nv50_ovly_new(drm, head->base.index, &ovly);
 	} else {
-		ret = nv50_wndw_new(drm, DRM_PLANE_TYPE_OVERLAY,
-				    head->base.index * 2 + 1, &wndw);
 		ret = nv50_wndw_new(drm, DRM_PLANE_TYPE_PRIMARY,
-				    head->base.index * 2 + 0, &wndw);
+				    head->base.index * 2 + 0, &base);
+		ret = nv50_wndw_new(drm, DRM_PLANE_TYPE_OVERLAY,
+				    head->base.index * 2 + 1, &ovly);
 	}
 	if (ret == 0)
 		ret = nv50_curs_new(drm, head->base.index, &curs);
@@ -508,7 +508,7 @@ nv50_head_create(struct drm_device *dev, int index)
 	}
 
 	crtc = &head->base.base;
-	drm_crtc_init_with_planes(dev, crtc, &wndw->plane, &curs->plane,
+	drm_crtc_init_with_planes(dev, crtc, &base->plane, &curs->plane,
 				  &nv50_head_func, "head-%d", head->base.index);
 	drm_crtc_helper_add(crtc, &nv50_head_help);
 	drm_mode_crtc_set_gamma_size(crtc, 256);