[PATCH v2 2/2] drm/vkms: return early if compose_plane fails

[Tales Lelo da Aparecida <tales.aparecida@xxxxxxxxx>]

Do not exit quietly from compose_plane. If any plane has an invalid
map, propagate the error value upwards. While here, add log messages
for the invalid index.

Signed-off-by: Tales Lelo da Aparecida <tales.aparecida@xxxxxxxxx>
---
 drivers/gpu/drm/vkms/vkms_composer.c | 30 ++++++++++++++++++----------
 1 file changed, 20 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/vkms/vkms_composer.c b/drivers/gpu/drm/vkms/vkms_composer.c
index b47ac170108c..c0a3b53cd155 100644
--- a/drivers/gpu/drm/vkms/vkms_composer.c
+++ b/drivers/gpu/drm/vkms/vkms_composer.c
@@ -149,16 +149,16 @@ static void blend(void *vaddr_dst, void *vaddr_src,
 	}
 }
 
-static void compose_plane(struct vkms_composer *primary_composer,
-			  struct vkms_composer *plane_composer,
-			  void *vaddr_out)
+static int compose_plane(struct vkms_composer *primary_composer,
+			 struct vkms_composer *plane_composer,
+			 void *vaddr_out)
 {
 	struct drm_framebuffer *fb = &plane_composer->fb;
 	void *vaddr;
 	void (*pixel_blend)(const u8 *p_src, u8 *p_dst);
 
 	if (WARN_ON(iosys_map_is_null(&plane_composer->map[0])))
-		return;
+		return -EINVAL;
 
 	vaddr = plane_composer->map[0].vaddr;
 
@@ -168,6 +168,8 @@ static void compose_plane(struct vkms_composer *primary_composer,
 		pixel_blend = &x_blend;
 
 	blend(vaddr_out, vaddr, primary_composer, plane_composer, pixel_blend);
+
+	return 0;
 }
 
 static int compose_active_planes(void **vaddr_out,
@@ -177,7 +179,7 @@ static int compose_active_planes(void **vaddr_out,
 	struct drm_framebuffer *fb = &primary_composer->fb;
 	struct drm_gem_object *gem_obj = drm_gem_fb_get_obj(fb, 0);
 	const void *vaddr;
-	int i;
+	int i, ret;
 
 	if (!*vaddr_out) {
 		*vaddr_out = kzalloc(gem_obj->size, GFP_KERNEL);
@@ -187,8 +189,10 @@ static int compose_active_planes(void **vaddr_out,
 		}
 	}
 
-	if (WARN_ON(iosys_map_is_null(&primary_composer->map[0])))
+	if (WARN_ON(iosys_map_is_null(&primary_composer->map[0]))) {
+		DRM_DEBUG_DRIVER("Failed to compose. Invalid map in the primary plane.");
 		return -EINVAL;
+	}
 
 	vaddr = primary_composer->map[0].vaddr;
 
@@ -198,10 +202,16 @@ static int compose_active_planes(void **vaddr_out,
 	 * planes should be in z-order and compose them associatively:
 	 * ((primary <- overlay) <- cursor)
 	 */
-	for (i = 1; i < crtc_state->num_active_planes; i++)
-		compose_plane(primary_composer,
-			      crtc_state->active_planes[i]->composer,
-			      *vaddr_out);
+	for (i = 1; i < crtc_state->num_active_planes; i++) {
+		ret = compose_plane(primary_composer,
+				    crtc_state->active_planes[i]->composer,
+				    *vaddr_out);
+		if (ret) {
+			DRM_DEBUG_DRIVER("Failed to compose. Invalid map in the active_planes[%d].",
+					 i);
+			return ret;
+		}
+	}
 
 	return 0;
 }
-- 
2.35.1