Re: [PATCH v2 linux-next] media: i2c: st-mipid02: replace of_node_put() with __free

[R Sundar <prosunofficial@gmail.com>]

Hi,

Thanks for the comments.

On 13/05/24 17:13, Benjamin Mugnier wrote:
> Hi,
> 
> I took sometime to reflect on this. Currently I favor drivers consistency.


> Merging this patch as is would introduce some differences between the
> vgxy61 and other drivers that follow the 'of_node_put' flow, which I
> think is not an improvement.
> 

I checked st-vgxy61.c file, I didn't find of_node_put().
Any file apart from this,  you want to see those changes? If yes let me 
know, please.
Meanwhile I am also looking into it.

This patch mainly reduce the goto error statements and increases 
readability of the code.

> Now, this patch is certainly good. Would it be possible to extend it to
> all other drivers using the 'of_node_put' ?
> 
yes, people are working on it to replace of_node_put() in many places. 
soon many patches can be expected to come in , for replacing of_node_put 
with auto cleanup module.
I am also adding these changes to few other files also.

Thanks,

> That would the consistency issue while improving code quality at the
> same time.
> 
> Thank you.
>  >
> On 4/29/24 18:37, R Sundar wrote:
>> Use the new cleanup magic to replace of_node_put() with
>> __free(device_node) marking to auto release and to simplify the error
>> paths.
>>
>> Suggested-by: Julia Lawall <julia.lawall@inria.fr>
>> Signed-off-by: R Sundar <prosunofficial@gmail.com>
>> ---
>>
>> Changes since v1 -
>>
>> - Added missed out __free() marking in mipid02_parse_tx_ep().
>> - In mipid02_parse_tx_ep(), In error case, return value is always -EINVAL.  so
>> sending the -EINVAL instead of ret variable value.
>>
>> Link to v1 - https://lore.kernel.org/all/20240427095643.11486-1-prosunofficial@gmail.com/#t
>>
>>   drivers/media/i2c/st-mipid02.c | 37 +++++++++-------------------------
>>   1 file changed, 9 insertions(+), 28 deletions(-)
>>
>> diff --git a/drivers/media/i2c/st-mipid02.c b/drivers/media/i2c/st-mipid02.c
>> index f250640729ca..bd3cf94f8534 100644
>> --- a/drivers/media/i2c/st-mipid02.c
>> +++ b/drivers/media/i2c/st-mipid02.c
>> @@ -715,31 +715,28 @@ static int mipid02_parse_rx_ep(struct mipid02_dev *bridge)
>>   	struct v4l2_fwnode_endpoint ep = { .bus_type = V4L2_MBUS_CSI2_DPHY };
>>   	struct i2c_client *client = bridge->i2c_client;
>>   	struct v4l2_async_connection *asd;
>> -	struct device_node *ep_node;
>>   	int ret;
>>   
>>   	/* parse rx (endpoint 0) */
>> -	ep_node = of_graph_get_endpoint_by_regs(bridge->i2c_client->dev.of_node,
>> -						0, 0);
>> +	struct device_node *ep_node __free(device_node) =
>> +		of_graph_get_endpoint_by_regs(bridge->i2c_client->dev.of_node, 0, 0);
>>   	if (!ep_node) {
>>   		dev_err(&client->dev, "unable to find port0 ep");
>> -		ret = -EINVAL;
>> -		goto error;
>> +		return -EINVAL;
>>   	}
>>   
>>   	ret = v4l2_fwnode_endpoint_parse(of_fwnode_handle(ep_node), &ep);
>>   	if (ret) {
>>   		dev_err(&client->dev, "Could not parse v4l2 endpoint %d\n",
>>   			ret);
>> -		goto error_of_node_put;
>> +		return ret;
>>   	}
>>   
>>   	/* do some sanity checks */
>>   	if (ep.bus.mipi_csi2.num_data_lanes > 2) {
>>   		dev_err(&client->dev, "max supported data lanes is 2 / got %d",
>>   			ep.bus.mipi_csi2.num_data_lanes);
>> -		ret = -EINVAL;
>> -		goto error_of_node_put;
>> +		return -EINVAL;
>>   	}
>>   
>>   	/* register it for later use */
>> @@ -750,7 +747,6 @@ static int mipid02_parse_rx_ep(struct mipid02_dev *bridge)
>>   	asd = v4l2_async_nf_add_fwnode_remote(&bridge->notifier,
>>   					      of_fwnode_handle(ep_node),
>>   					      struct v4l2_async_connection);
>> -	of_node_put(ep_node);
>>   
>>   	if (IS_ERR(asd)) {
>>   		dev_err(&client->dev, "fail to register asd to notifier %ld",
>> @@ -764,46 +760,31 @@ static int mipid02_parse_rx_ep(struct mipid02_dev *bridge)
>>   		v4l2_async_nf_cleanup(&bridge->notifier);
>>   
>>   	return ret;
>> -
>> -error_of_node_put:
>> -	of_node_put(ep_node);
>> -error:
>> -
>> -	return ret;
>>   }
>>   
>>   static int mipid02_parse_tx_ep(struct mipid02_dev *bridge)
>>   {
>>   	struct v4l2_fwnode_endpoint ep = { .bus_type = V4L2_MBUS_PARALLEL };
>>   	struct i2c_client *client = bridge->i2c_client;
>> -	struct device_node *ep_node;
>>   	int ret;
>>   
>>   	/* parse tx (endpoint 2) */
>> -	ep_node = of_graph_get_endpoint_by_regs(bridge->i2c_client->dev.of_node,
>> -						2, 0);
>> +	struct device_node *ep_node __free(device_node) =
>> +		of_graph_get_endpoint_by_regs(bridge->i2c_client->dev.of_node, 2, 0);
>>   	if (!ep_node) {
>>   		dev_err(&client->dev, "unable to find port1 ep");
>> -		ret = -EINVAL;
>> -		goto error;
>> +		return -EINVAL;
>>   	}
>>   
>>   	ret = v4l2_fwnode_endpoint_parse(of_fwnode_handle(ep_node), &ep);
>>   	if (ret) {
>>   		dev_err(&client->dev, "Could not parse v4l2 endpoint\n");
>> -		goto error_of_node_put;
>> +		return -EINVAL;
>>   	}
>>   
>> -	of_node_put(ep_node);
>>   	bridge->tx = ep;
>>   
>>   	return 0;
>> -
>> -error_of_node_put:
>> -	of_node_put(ep_node);
>> -error:
>> -
>> -	return -EINVAL;
>>   }
>>   
>>   static int mipid02_probe(struct i2c_client *client)
>