Re: [PATCH 5/5] drm: lcdif: Use drm_bridge_connector

[Liu Ying <victor.liu@nxp.com>]

On 10/18/2024, Biju Das wrote:
> Hi Liu Ying,

Hi Biju,

> 
> Thanks for the patch.

Thanks for your review.

> 
>> -----Original Message-----
>> From: linux-arm-kernel <linux-arm-kernel-bounces@lists.infradead.org> On Behalf Of Liu Ying
>> Sent: Friday, October 18, 2024 7:48 AM
>> Subject: [PATCH 5/5] drm: lcdif: Use drm_bridge_connector
>>
>> Initialize a connector by calling drm_bridge_connector_init() for each encoder so that down stream
>> bridge drivers don't need to create connectors any more.
>>
>> Signed-off-by: Liu Ying <victor.liu@nxp.com>
>> ---
>>  drivers/gpu/drm/mxsfb/Kconfig     |  1 +
>>  drivers/gpu/drm/mxsfb/lcdif_drv.c | 17 ++++++++++++++++-
>>  2 files changed, 17 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/mxsfb/Kconfig b/drivers/gpu/drm/mxsfb/Kconfig index
>> 264e74f45554..06c95e556380 100644
>> --- a/drivers/gpu/drm/mxsfb/Kconfig
>> +++ b/drivers/gpu/drm/mxsfb/Kconfig
>> @@ -27,6 +27,7 @@ config DRM_IMX_LCDIF
>>  	depends on DRM && OF
>>  	depends on COMMON_CLK
>>  	depends on ARCH_MXC || COMPILE_TEST
>> +	select DRM_BRIDGE_CONNECTOR
>>  	select DRM_CLIENT_SELECTION
>>  	select DRM_MXS
>>  	select DRM_KMS_HELPER
>> diff --git a/drivers/gpu/drm/mxsfb/lcdif_drv.c b/drivers/gpu/drm/mxsfb/lcdif_drv.c
>> index 58ccad9c425d..d4521da6675e 100644
>> --- a/drivers/gpu/drm/mxsfb/lcdif_drv.c
>> +++ b/drivers/gpu/drm/mxsfb/lcdif_drv.c
>> @@ -16,7 +16,9 @@
>>
>>  #include <drm/drm_atomic_helper.h>
>>  #include <drm/drm_bridge.h>
>> +#include <drm/drm_bridge_connector.h>
>>  #include <drm/drm_client_setup.h>
>> +#include <drm/drm_connector.h>
>>  #include <drm/drm_drv.h>
>>  #include <drm/drm_encoder.h>
>>  #include <drm/drm_fbdev_dma.h>
>> @@ -56,6 +58,7 @@ static int lcdif_attach_bridge(struct lcdif_drm_private *lcdif)
>>  		struct device_node *remote;
>>  		struct of_endpoint of_ep;
>>  		struct drm_encoder *encoder;
>> +		struct drm_connector *connector;
>>
>>  		remote = of_graph_get_remote_port_parent(ep);
>>  		if (!of_device_is_available(remote)) { @@ -97,13 +100,25 @@ static int
>> lcdif_attach_bridge(struct lcdif_drm_private *lcdif)
>>  			return ret;
>>  		}
>>
>> -		ret = drm_bridge_attach(encoder, bridge, NULL, 0);
>> +		ret = drm_bridge_attach(encoder, bridge, NULL,
>> +					DRM_BRIDGE_ATTACH_NO_CONNECTOR);
>>  		if (ret) {
>>  			of_node_put(ep);
>>  			return dev_err_probe(dev, ret,
>>  					     "Failed to attach bridge for endpoint%u\n",
>>  					     of_ep.id);
>>  		}
>> +
>> +		connector = drm_bridge_connector_init(lcdif->drm, encoder);
>> +		if (IS_ERR(connector)) {
>> +			ret = PTR_ERR(connector);
>> +			dev_err(dev, "Failed to initialize bridge connector: %d\n",
>> +				ret);
>> +			of_node_put(ep);
>> +			return ret;
> 
> Maybe same error path style like above??
> 		of_node_put(ep);
> 		return dev_err_probe(dev, PTR_ERR(connector),"Failed to initialize bridge connector");

I thought about that and decided not to use dev_err_probe()
because I don't think drm_bridge_connector_init() may return
-EPROBE_DEFER, no?

> 
> Cheers,
> Biju
> 
>> +		}
>> +
>> +		drm_connector_attach_encoder(connector, encoder);
>>  	}
>>
>>  	return 0;
>> --
>> 2.34.1
>>
> 

-- 
Regards,
Liu Ying