Re: [PATCH v2 04/11] media: i2c: ov5645: Use dev_err_probe instead of dev_err

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Prabhakar,

Thank you for the patch.

On Tue, Sep 10, 2024 at 06:06:03PM +0100, Prabhakar wrote:
> From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> 
> Drop dev_err() and use the dev_err_probe() helper on probe path.
> 
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> ---
>  drivers/media/i2c/ov5645.c | 74 +++++++++++++++-----------------------
>  1 file changed, 28 insertions(+), 46 deletions(-)
> 
> diff --git a/drivers/media/i2c/ov5645.c b/drivers/media/i2c/ov5645.c
> index 78b86438c798..9e6ff1f1b9ac 100644
> --- a/drivers/media/i2c/ov5645.c
> +++ b/drivers/media/i2c/ov5645.c
> @@ -1076,51 +1076,37 @@ static int ov5645_probe(struct i2c_client *client)
>  	ov5645->dev = dev;
>  
>  	endpoint = of_graph_get_endpoint_by_regs(dev->of_node, 0, -1);
> -	if (!endpoint) {
> -		dev_err(dev, "endpoint node not found\n");
> -		return -EINVAL;
> -	}
> +	if (!endpoint)
> +		return dev_err_probe(dev, -EINVAL, "endpoint node not found\n");
>  
>  	ret = v4l2_fwnode_endpoint_parse(of_fwnode_handle(endpoint),
>  					 &ov5645->ep);
>  
>  	of_node_put(endpoint);
>  
> -	if (ret < 0) {
> -		dev_err(dev, "parsing endpoint node failed\n");
> -		return ret;
> -	}
> +	if (ret < 0)
> +		return dev_err_probe(dev, ret, "parsing endpoint node failed\n");
>  
> -	if (ov5645->ep.bus_type != V4L2_MBUS_CSI2_DPHY) {
> -		dev_err(dev, "invalid bus type, must be CSI2\n");
> -		return -EINVAL;
> -	}
> +	if (ov5645->ep.bus_type != V4L2_MBUS_CSI2_DPHY)
> +		return dev_err_probe(dev, -EINVAL, "invalid bus type, must be CSI2\n");
>  
>  	/* get system clock (xclk) */
>  	ov5645->xclk = devm_clk_get(dev, NULL);
> -	if (IS_ERR(ov5645->xclk)) {
> -		dev_err(dev, "could not get xclk");
> -		return PTR_ERR(ov5645->xclk);
> -	}
> +	if (IS_ERR(ov5645->xclk))
> +		return dev_err_probe(dev, PTR_ERR(ov5645->xclk), "could not get xclk");
>  
>  	ret = of_property_read_u32(dev->of_node, "clock-frequency", &xclk_freq);
> -	if (ret) {
> -		dev_err(dev, "could not get xclk frequency\n");
> -		return ret;
> -	}
> +	if (ret)
> +		return dev_err_probe(dev, ret, "could not get xclk frequency\n");
>  
>  	/* external clock must be 24MHz, allow 1% tolerance */
> -	if (xclk_freq < 23760000 || xclk_freq > 24240000) {
> -		dev_err(dev, "external clock frequency %u is not supported\n",
> -			xclk_freq);
> -		return -EINVAL;
> -	}
> +	if (xclk_freq < 23760000 || xclk_freq > 24240000)
> +		return dev_err_probe(dev, -EINVAL, "external clock frequency %u is not supported\n",
> +				     xclk_freq);
>  
>  	ret = clk_set_rate(ov5645->xclk, xclk_freq);
> -	if (ret) {
> -		dev_err(dev, "could not set xclk frequency\n");
> -		return ret;
> -	}
> +	if (ret)
> +		return dev_err_probe(dev, ret, "could not set xclk frequency\n");
>  
>  	for (i = 0; i < OV5645_NUM_SUPPLIES; i++)
>  		ov5645->supplies[i].supply = ov5645_supply_name[i];
> @@ -1131,16 +1117,12 @@ static int ov5645_probe(struct i2c_client *client)
>  		return ret;
>  
>  	ov5645->enable_gpio = devm_gpiod_get(dev, "enable", GPIOD_OUT_HIGH);
> -	if (IS_ERR(ov5645->enable_gpio)) {
> -		dev_err(dev, "cannot get enable gpio\n");
> -		return PTR_ERR(ov5645->enable_gpio);
> -	}
> +	if (IS_ERR(ov5645->enable_gpio))
> +		return dev_err_probe(dev, PTR_ERR(ov5645->enable_gpio), "cannot get enable gpio\n");

Those lines are getting long. We usually try to wrap at 80 columns for
sensor drivers:

		return dev_err_probe(dev, PTR_ERR(ov5645->enable_gpio),
				     "cannot get enable gpio\n");

Same elsewhere. I'll let Sakari decide.

>  
>  	ov5645->rst_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
> -	if (IS_ERR(ov5645->rst_gpio)) {
> -		dev_err(dev, "cannot get reset gpio\n");
> -		return PTR_ERR(ov5645->rst_gpio);
> -	}
> +	if (IS_ERR(ov5645->rst_gpio))
> +		return dev_err_probe(dev, PTR_ERR(ov5645->rst_gpio), "cannot get reset gpio\n");
>  
>  	mutex_init(&ov5645->power_lock);
>  
> @@ -1177,9 +1159,9 @@ static int ov5645_probe(struct i2c_client *client)
>  	ov5645->sd.ctrl_handler = &ov5645->ctrls;
>  
>  	if (ov5645->ctrls.error) {
> -		dev_err(dev, "%s: control initialization error %d\n",
> -		       __func__, ov5645->ctrls.error);
>  		ret = ov5645->ctrls.error;
> +		dev_err_probe(dev, ret, "%s: control initialization error %d\n",
> +			      __func__, ov5645->ctrls.error);
>  		goto free_ctrl;
>  	}
>  
> @@ -1192,7 +1174,7 @@ static int ov5645_probe(struct i2c_client *client)
>  
>  	ret = media_entity_pads_init(&ov5645->sd.entity, 1, &ov5645->pad);
>  	if (ret < 0) {
> -		dev_err(dev, "could not register media entity\n");
> +		dev_err_probe(dev, ret, "could not register media entity\n");
>  		goto free_ctrl;
>  	}
>  
> @@ -1202,14 +1184,14 @@ static int ov5645_probe(struct i2c_client *client)
>  
>  	ret = ov5645_read_reg(ov5645, OV5645_CHIP_ID_HIGH, &chip_id_high);
>  	if (ret < 0 || chip_id_high != OV5645_CHIP_ID_HIGH_BYTE) {
> -		dev_err(dev, "could not read ID high\n");
>  		ret = -ENODEV;
> +		dev_err_probe(dev, ret, "could not read ID high\n");
>  		goto power_down;
>  	}
>  	ret = ov5645_read_reg(ov5645, OV5645_CHIP_ID_LOW, &chip_id_low);
>  	if (ret < 0 || chip_id_low != OV5645_CHIP_ID_LOW_BYTE) {
> -		dev_err(dev, "could not read ID low\n");
>  		ret = -ENODEV;
> +		dev_err_probe(dev, ret, "could not read ID low\n");
>  		goto power_down;
>  	}
>  
> @@ -1218,24 +1200,24 @@ static int ov5645_probe(struct i2c_client *client)
>  	ret = ov5645_read_reg(ov5645, OV5645_AEC_PK_MANUAL,
>  			      &ov5645->aec_pk_manual);
>  	if (ret < 0) {
> -		dev_err(dev, "could not read AEC/AGC mode\n");
>  		ret = -ENODEV;
> +		dev_err_probe(dev, ret, "could not read AEC/AGC mode\n");
>  		goto power_down;
>  	}
>  
>  	ret = ov5645_read_reg(ov5645, OV5645_TIMING_TC_REG20,
>  			      &ov5645->timing_tc_reg20);
>  	if (ret < 0) {
> -		dev_err(dev, "could not read vflip value\n");
>  		ret = -ENODEV;
> +		dev_err_probe(dev, ret, "could not read vflip value\n");
>  		goto power_down;
>  	}
>  
>  	ret = ov5645_read_reg(ov5645, OV5645_TIMING_TC_REG21,
>  			      &ov5645->timing_tc_reg21);
>  	if (ret < 0) {
> -		dev_err(dev, "could not read hflip value\n");
>  		ret = -ENODEV;
> +		dev_err_probe(dev, ret, "could not read hflip value\n");
>  		goto power_down;
>  	}
>  
> @@ -1243,7 +1225,7 @@ static int ov5645_probe(struct i2c_client *client)
>  
>  	ret = v4l2_async_register_subdev(&ov5645->sd);
>  	if (ret < 0) {
> -		dev_err(dev, "could not register v4l2 device\n");
> +		dev_err_probe(dev, ret, "could not register v4l2 device\n");
>  		goto power_down;
>  	}
>  

The probe function looks really young, I think it would benefit from
being broken down in multiple functions.

-- 
Regards,

Laurent Pinchart