Re: [PATCH 5/7] iio: adc: rockchip_saradc: Use dev_err_probe

AngeloGioacchino Del Regno
2023-05-17T10:40:53Z

Il 17/05/23 01:00, Shreeya Patel ha scritto:
> Use dev_err_probe instead of dev_err in probe function,
> which simplifies code a little bit and prints the error
> code.
>
> Signed-off-by: Shreeya Patel <shreeya.patel@collabora.com>
> ---
> drivers/iio/adc/rockchip_saradc.c | 45 ++++++++++++++-----------------
> 1 file changed, 20 insertions(+), 25 deletions(-)
>
> diff --git a/drivers/iio/adc/rockchip_saradc.c b/drivers/iio/adc/rockchip_saradc.c
> index 5e1e8575bc76..a52021fd477d 100644
> --- a/drivers/iio/adc/rockchip_saradc.c
> +++ b/drivers/iio/adc/rockchip_saradc.c

..snip..

> @@ -494,23 +492,20 @@ static int rockchip_saradc_probe(struct platform_device *pdev)
> * This may become user-configurable in the future.
> */
> ret = clk_set_rate(info->clk, info->data->clk_rate);
> - if (ret < 0) {
> - dev_err(&pdev->dev, "failed to set adc clk rate, %d\n", ret);
> - return ret;
> - }
> + if (ret < 0)
> + return dev_err_probe(&pdev->dev, ret,
> + "failed to set adc clk rate\n");
>
> ret = regulator_enable(info->vref);
> - if (ret < 0) {
> - dev_err(&pdev->dev, "failed to enable vref regulator\n");
> - return ret;
> - }
> + if (ret < 0)
> + return dev_err_probe(&pdev->dev, ret,
> + "failed to enable vref regulator\n");
> +
> ret = devm_add_action_or_reset(&pdev->dev,
> rockchip_saradc_regulator_disable, info);
> - if (ret) {
> - dev_err(&pdev->dev, "failed to register devm action, %d\n",
> - ret);
> - return ret;
> - }
> + if (ret)
> + return dev_err_probe(&pdev->dev, ret,
> + "failed to register devm action\n");

It's not your fault - and it's about a pre-existing issue, but there's that:
you're returning an error if devm_add_action_or_reset() fails (which is highly
unlikely), but you're leaving the regulator enabled!

As for how to proceed here, I would suggest to fix this issue in a separated
commit (before the dev_err_probe() conversion); it'd look like...

if (ret) {
regulator_disable(info->vref);
dev_err( .... blurb );
return ret;
}

and after the conversion it'd look like...

if (ret) {
regulator_disable(info->vref);
return dev_err_probe( ... blurb );
}

Cheers,
Angelo

>
> ret = regulator_get_voltage(info->vref);
> if (ret < 0)