Re: [PATCH v13 11/17] drm/bridge: analogix_dp: Apply drm_bridge_connector helper

Luca Ceresoli
2026-04-10T07:42:17Z

Hello Damon,

On Thu Apr 9, 2026 at 8:52 AM CEST, Damon Ding wrote:
> Initialize bridge_connector for both Rockchip and Exynos encoder sides.
> Then, make DRM_BRIDGE_ATTACH_NO_CONNECTOR mandatory for Analogix bridge
> side, as the private &drm_connector is no longer created.
>
> The previous &drm_connector_funcs and &drm_connector_helper_funcs APIs
> are replaced by the corresponding &drm_bridge_funcs APIs:
>
> analogix_dp_atomic_check() -> analogix_dp_bridge_atomic_check()
> analogix_dp_detect() -> analogix_dp_bridge_detect()
> analogix_dp_get_modes() -> analogix_dp_bridge_get_modes()
> analogix_dp_bridge_edid_read()
>
> Additionally, the compatibilities of Analogix DP bridge based on whether
> the next bridge is a 'panel'. If it is, OP_MODES and OP_DETECT are
> supported; If not (the next bridge is a 'monitor' or a bridge chip),
> OP_EDID and OP_DETECT are supported.
>
> The devm_drm_bridge_add() is placed in analogix_dp_bind() instead of
> analogix_dp_probe(), because the type of next bridge (the panel, monitor
> or bridge chip) can only be determined after the probe process has fully
> completed.
>
> Signed-off-by: Damon Ding <damon.ding@rock-chips.com>
> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
> Tested-by: Heiko Stuebner <heiko@sntech.de> # rk3588

I noticed two issues, sorry I haven't catched them before...

> @@ -1580,7 +1533,8 @@ EXPORT_SYMBOL_GPL(analogix_dp_unbind);
>
> int analogix_dp_start_crc(struct drm_connector *connector)
> {
> - struct analogix_dp_device *dp = to_dp(connector);
> + struct analogix_dp_device *dp;
> + struct drm_bridge *bridge;
>
> if (!connector->state->crtc) {
> DRM_ERROR("Connector %s doesn't currently have a CRTC.\n",
> @@ -1588,13 +1542,26 @@ int analogix_dp_start_crc(struct drm_connector *connector)
> return -EINVAL;
> }
>
> + bridge = drm_bridge_chain_get_first_bridge(connector->encoder);
> + if (bridge->type != DRM_MODE_CONNECTOR_eDP)
> + return -EINVAL;
> +
> + dp = to_dp(bridge);
> +
> return drm_dp_start_crc(&dp->aux, connector->state->crtc);
> }

drm_bridge_chain_get_first_bridge() takes a reference, you must call
drm_bridge_put(bridge) before returning. Given there are two return paths I
suggest:

- struct drm_bridge *bridge;

- bridge = drm_bridge_chain_get_first_bridge(connector->encoder);
+ struct drm_bridge *bridge __free(drm_bridge_put) =
+ drm_bridge_chain_get_first_bridge(connector->encoder);

> EXPORT_SYMBOL_GPL(analogix_dp_start_crc);
>
> int analogix_dp_stop_crc(struct drm_connector *connector)
> {
> - struct analogix_dp_device *dp = to_dp(connector);
> + struct analogix_dp_device *dp;
> + struct drm_bridge *bridge;
> +
> + bridge = drm_bridge_chain_get_first_bridge(connector->encoder);
> + if (bridge->type != DRM_MODE_CONNECTOR_eDP)
> + return -EINVAL;
> +
> + dp = to_dp(bridge);
>
> return drm_dp_stop_crc(&dp->aux);
> }

Same here:

- struct drm_bridge *bridge;

- bridge = drm_bridge_chain_get_first_bridge(connector->encoder);
+ struct drm_bridge *bridge __free(drm-bridge_put) =
+ drm_bridge_chain_get_first_bridge(connector->encoder);

With the above two changes you can add to v14:

+Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>

Luca

--
Luca Ceresoli, Bootlin
Embedded Linux and Kernel engineering