Re: [PATCH 1/2] media: i2c: ov5670: Use dev_err_probe in probe function

[Jacopo Mondi]

Hi Luca

On Fri, Feb 10, 2023 at 09:33:17PM +0100, Luca Weiss wrote:
> Replace the unusual const char *err_msg usage with dev_err_probe which
> also handles -EPROBE_DEFER better by not printing the message to kmsg.
>
> Signed-off-by: Luca Weiss <luca@xxxxxxxxx>

Thanks! The *err_msg thing was weird indeed

> ---
>  drivers/media/i2c/ov5670.c | 37 ++++++++++++-------------------------
>  1 file changed, 12 insertions(+), 25 deletions(-)
>
> diff --git a/drivers/media/i2c/ov5670.c b/drivers/media/i2c/ov5670.c
> index f79d908f4531..189920571df2 100644
> --- a/drivers/media/i2c/ov5670.c
> +++ b/drivers/media/i2c/ov5670.c
> @@ -2648,17 +2648,13 @@ static int ov5670_gpio_probe(struct ov5670 *ov5670)
>  static int ov5670_probe(struct i2c_client *client)
>  {
>  	struct ov5670 *ov5670;
> -	const char *err_msg;
>  	u32 input_clk = 0;
>  	bool full_power;
>  	int ret;
>
>  	ov5670 = devm_kzalloc(&client->dev, sizeof(*ov5670), GFP_KERNEL);
> -	if (!ov5670) {
> -		ret = -ENOMEM;
> -		err_msg = "devm_kzalloc() error";
> -		goto error_print;
> -	}
> +	if (!ov5670)
> +		return -ENOMEM;
>
>  	ov5670->xvclk = devm_clk_get(&client->dev, NULL);
>  	if (!IS_ERR_OR_NULL(ov5670->xvclk))
> @@ -2680,29 +2676,23 @@ static int ov5670_probe(struct i2c_client *client)
>  	v4l2_i2c_subdev_init(&ov5670->sd, client, &ov5670_subdev_ops);
>
>  	ret = ov5670_regulators_probe(ov5670);
> -	if (ret) {
> -		err_msg = "Regulators probe failed";
> -		goto error_print;
> -	}
> +	if (ret)
> +		return dev_err_probe(&client->dev, ret, "Regulators probe failed\n");
>
>  	ret = ov5670_gpio_probe(ov5670);
> -	if (ret) {
> -		err_msg = "GPIO probe failed";
> -		goto error_print;
> -	}
> +	if (ret)
> +		return dev_err_probe(&client->dev, ret, "GPIO probe failed\n");

>From now on, I don't think there are functions that can return
-EPROBE_DEFER and you could

        if (ret) {
                dev_err(...)
                goto ...;
        }

But if others are fine with what you have and consider using
dev_err_probe() better regardless if the called function can
return -EPROBE_DEFER or not, I'm fine with what you have here.

>
>  	full_power = acpi_dev_state_d0(&client->dev);
>  	if (full_power) {
>  		ret = ov5670_runtime_resume(&client->dev);
> -		if (ret) {
> -			err_msg = "Power up failed";
> -			goto error_print;
> -		}
> +		if (ret)
> +			return dev_err_probe(&client->dev, ret, "Power up failed\n");
>
>  		/* Check module identity */
>  		ret = ov5670_identify_module(ov5670);
>  		if (ret) {
> -			err_msg = "ov5670_identify_module() error";
> +			dev_err_probe(&client->dev, ret, "ov5670_identify_module() error\n");
>  			goto error_power_off;
>  		}
>  	}
> @@ -2714,7 +2704,7 @@ static int ov5670_probe(struct i2c_client *client)
>
>  	ret = ov5670_init_controls(ov5670);
>  	if (ret) {
> -		err_msg = "ov5670_init_controls() error";
> +		dev_err_probe(&client->dev, ret, "ov5670_init_controls() error\n");
>  		goto error_mutex_destroy;
>  	}
>
> @@ -2727,7 +2717,7 @@ static int ov5670_probe(struct i2c_client *client)
>  	ov5670->pad.flags = MEDIA_PAD_FL_SOURCE;
>  	ret = media_entity_pads_init(&ov5670->sd.entity, 1, &ov5670->pad);
>  	if (ret) {
> -		err_msg = "media_entity_pads_init() error";
> +		dev_err_probe(&client->dev, ret, "media_entity_pads_init() error\n");
>  		goto error_handler_free;
>  	}
>
> @@ -2741,7 +2731,7 @@ static int ov5670_probe(struct i2c_client *client)
>  	/* Async register for subdev */
>  	ret = v4l2_async_register_subdev_sensor(&ov5670->sd);
>  	if (ret < 0) {
> -		err_msg = "v4l2_async_register_subdev() error";
> +		dev_err_probe(&client->dev, ret, "v4l2_async_register_subdev() error\n");
>  		goto error_pm_disable;
>  	}
>
> @@ -2764,9 +2754,6 @@ static int ov5670_probe(struct i2c_client *client)
>  	if (full_power)
>  		ov5670_runtime_suspend(&client->dev);
>
> -error_print:
> -	dev_err(&client->dev, "%s: %s %d\n", __func__, err_msg, ret);
> -
>  	return ret;
>  }
>
>
> --
> 2.39.1
>