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

[Tales Lelo da Aparecida]

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.aparec...@gmail.com>
---
 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