[PATCH v3 3/4] drm: rcar-du: encoder: convert to of_drm_find_and_get_bridge()

Luca Ceresoli
2026-03-18T09:40:05Z

of_drm_find_and_get_bridge() which gets a bridge reference, and ensure it
is put when done.

We need to handle the two cases: when a panel_bridge is added and when it
isn't. So:

* in the 'else' case a panel_bridge is not added and bridge is found: use
of_drm_find_and_get_bridge() to get a reference to the found bridge
* in the 'then' case a panel_bridge is found using a devm function which
already takes a refcount and will put it on removal, but we need to take
another so the following code in this function always get exactly one
reference that it needs to put

In order to put the reference, add the needed drm_bridge_put() calls in the
existing cleanup function.

Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
---
drivers/gpu/drm/renesas/rcar-du/rcar_du_encoder.c | 28 ++++++++++++++++++-----
drivers/gpu/drm/renesas/rcar-du/rcar_du_encoder.h | 1 +
drivers/gpu/drm/renesas/rcar-du/rcar_du_kms.c | 2 ++
3 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/renesas/rcar-du/rcar_du_encoder.c b/drivers/gpu/drm/renesas/rcar-du/rcar_du_encoder.c
index 7ecec7b04a8d..5789fc75092f 100644
--- a/drivers/gpu/drm/renesas/rcar-du/rcar_du_encoder.c
+++ b/drivers/gpu/drm/renesas/rcar-du/rcar_du_encoder.c
@@ -51,7 +51,7 @@ int rcar_du_encoder_init(struct rcar_du_device *rcdu,
{
struct rcar_du_encoder *renc;
struct drm_connector *connector;
- struct drm_bridge *bridge;
+ struct drm_bridge *bridge __free(drm_bridge_put) = NULL;
int ret;

/*
@@ -69,20 +69,26 @@ int rcar_du_encoder_init(struct rcar_du_device *rcdu,

bridge = devm_drm_panel_bridge_add_typed(rcdu->dev, panel,
DRM_MODE_CONNECTOR_DPI);
- if (IS_ERR(bridge))
- return PTR_ERR(bridge);
+ if (IS_ERR(bridge)) {
+ // Inhibit the cleanup action on an ERR_PTR
+ ret = PTR_ERR(bridge);
+ bridge = NULL;
+ return ret;
+ }
+
+ drm_bridge_get(bridge);
} else {
- bridge = of_drm_find_bridge(enc_node);
+ bridge = of_drm_find_and_get_bridge(enc_node);
if (!bridge)
return -EPROBE_DEFER;

if (output == RCAR_DU_OUTPUT_LVDS0 ||
output == RCAR_DU_OUTPUT_LVDS1)
- rcdu->lvds[output - RCAR_DU_OUTPUT_LVDS0] = bridge;
+ rcdu->lvds[output - RCAR_DU_OUTPUT_LVDS0] = drm_bridge_get(bridge);

if (output == RCAR_DU_OUTPUT_DSI0 ||
output == RCAR_DU_OUTPUT_DSI1)
- rcdu->dsi[output - RCAR_DU_OUTPUT_DSI0] = bridge;
+ rcdu->dsi[output - RCAR_DU_OUTPUT_DSI0] = drm_bridge_get(bridge);
}

/*
@@ -135,3 +141,13 @@ int rcar_du_encoder_init(struct rcar_du_device *rcdu,

return drm_connector_attach_encoder(connector, &renc->base);
}
+
+void rcar_du_encoder_cleanup(struct rcar_du_device *rcdu)
+{
+ int i;
+
+ for (i = 0; i < RCAR_DU_MAX_LVDS; i++)
+ drm_bridge_put(rcdu->lvds[i]);
+ for (i = 0; i < RCAR_DU_MAX_DSI; i++)
+ drm_bridge_put(rcdu->dsi[i]);
+}
diff --git a/drivers/gpu/drm/renesas/rcar-du/rcar_du_encoder.h b/drivers/gpu/drm/renesas/rcar-du/rcar_du_encoder.h
index e5ec8fbb3979..b2b5e93f30f8 100644
--- a/drivers/gpu/drm/renesas/rcar-du/rcar_du_encoder.h
+++ b/drivers/gpu/drm/renesas/rcar-du/rcar_du_encoder.h
@@ -25,5 +25,6 @@ struct rcar_du_encoder {
int rcar_du_encoder_init(struct rcar_du_device *rcdu,
enum rcar_du_output output,
struct device_node *enc_node);
+void rcar_du_encoder_cleanup(struct rcar_du_device *rcdu);

#endif /* __RCAR_DU_ENCODER_H__ */
diff --git a/drivers/gpu/drm/renesas/rcar-du/rcar_du_kms.c b/drivers/gpu/drm/renesas/rcar-du/rcar_du_kms.c
index 60e6f43b8ab2..82d16a999ee6 100644
--- a/drivers/gpu/drm/renesas/rcar-du/rcar_du_kms.c
+++ b/drivers/gpu/drm/renesas/rcar-du/rcar_du_kms.c
@@ -836,6 +836,8 @@ static void rcar_du_modeset_cleanup(struct drm_device *dev, void *res)

for (i = 0; i < ARRAY_SIZE(rcdu->cmms); ++i)
platform_device_put(rcdu->cmms[i]);
+
+ rcar_du_encoder_cleanup(rcdu);
}

int rcar_du_modeset_init(struct rcar_du_device *rcdu)

--
2.53.0