drm/bridge: select_bus_fmt_recursive(): put the bridge obtained by drm_bridge_get_pre...

The bridge returned by drm_bridge_get_prev_bridge() is refcounted. Put it
when done.

select_bus_fmt_recursive() has several return points, and ensuring
drm_bridge_put() is always called in the right place would be error-prone
(especially with future changes to the select_bus_fmt_recursive() code) and
make code uglier. Instead use a scope-based free, which is future-proof and
a lot cleaner.

Reviewed-by: Maxime Ripard <mripard@kernel.org>
Link: https://lore.kernel.org/r/20250709-drm-bridge-alloc-getput-drm_bridge_get_prev_bridge-v1-2-34ba6f395aaa@bootlin.com
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>

diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c
index dd45d9b504d8f2802f4ee93e4b4d893d8535abea..c3bfcd735a3c426a147bf0a7427b3d2cd0df3524 100644 (file)
--- a/drivers/gpu/drm/drm_bridge.c
+++ b/drivers/gpu/drm/drm_bridge.c
@@ -941,11 +941,11 @@ static int select_bus_fmt_recursive(struct drm_bridge *first_bridge,
 {
        unsigned int i, num_in_bus_fmts = 0;
        struct drm_bridge_state *cur_state;
-       struct drm_bridge *prev_bridge;
+       struct drm_bridge *prev_bridge __free(drm_bridge_put) =
+               drm_bridge_get_prev_bridge(cur_bridge);
        u32 *in_bus_fmts;
        int ret;
 
-       prev_bridge = drm_bridge_get_prev_bridge(cur_bridge);
        cur_state = drm_atomic_get_new_bridge_state(crtc_state->state,
                                                    cur_bridge);