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

[Damon Ding <damon.ding@rock-chips.com>]

Hi Luca,

On 4/10/2026 3:41 PM, Luca Ceresoli wrote:
> 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>
> 
> 

Ah, your previous commit added this nice reference handling. Thanks for 
the kind review.

I'll fix it in v14.

Best regards,
Damon