drm/bridge: lontium-lt9611uxc: switch to of_drm_get_bridge_by_endpoint()

This driver calls drm_of_find_panel_or_bridge() with a NULL pointer in the
@panel parameter, thus using a reduced feature set of that function.
Replace this call with the simpler of_drm_get_bridge_by_endpoint().

Since of_drm_get_bridge_by_endpoint() increases the refcount of the
returned bridge, ensure it is put on removal. To achieve this, instead of
adding an explicit drm_bridge_put(), migrate to the bridge::next_bridge
pointer which is automatically put when the bridge is eventually freed.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Link: https://patch.msgid.link/20260511-drm-bridge-alloc-getput-panel_or_bridge-v6-6-f61c9e498b3f@bootlin.com
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>

diff --git a/drivers/gpu/drm/bridge/lontium-lt9611uxc.c b/drivers/gpu/drm/bridge/lontium-lt9611uxc.c
index 11aab07d88df646a54fea287030a183eb823b26d..9427cc2358ae1a3211ec50a844d820e1e9e53efa 100644 (file)
--- a/drivers/gpu/drm/bridge/lontium-lt9611uxc.c
+++ b/drivers/gpu/drm/bridge/lontium-lt9611uxc.c
@@ -35,7 +35,6 @@
 struct lt9611uxc {
        struct device *dev;
        struct drm_bridge bridge;
-       struct drm_bridge *next_bridge;
 
        struct regmap *regmap;
        /* Protects all accesses to registers by stopping the on-chip MCU */
@@ -284,7 +283,7 @@ static int lt9611uxc_bridge_attach(struct drm_bridge *bridge,
 {
        struct lt9611uxc *lt9611uxc = bridge_to_lt9611uxc(bridge);
 
-       return drm_bridge_attach(encoder, lt9611uxc->next_bridge,
+       return drm_bridge_attach(encoder, lt9611uxc->bridge.next_bridge,
                                 bridge, flags);
 }
 
@@ -487,7 +486,11 @@ static int lt9611uxc_parse_dt(struct device *dev,
 
        lt9611uxc->dsi1_node = of_graph_get_remote_node(dev->of_node, 1, -1);
 
-       return drm_of_find_panel_or_bridge(dev->of_node, 2, -1, NULL, &lt9611uxc->next_bridge);
+       lt9611uxc->bridge.next_bridge = of_drm_get_bridge_by_endpoint(dev->of_node, 2, -1);
+       if (IS_ERR(lt9611uxc->bridge.next_bridge))
+               return PTR_ERR(lt9611uxc->bridge.next_bridge);
+
+       return 0;
 }
 
 static int lt9611uxc_gpio_init(struct lt9611uxc *lt9611uxc)