linux-kernel - Re: [PATCH] mfd: stmfx: Improve error message triggered by regulator fault in .remove()

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Message-ID: <YgpdPTDurgsvR9mk@google.com>
Date:   Mon, 14 Feb 2022 13:46:37 +0000
From:   Lee Jones <lee.jones@...aro.org>
To:     Uwe Kleine-König 
        <u.kleine-koenig@...gutronix.de>
Cc:     Maxime Coquelin <mcoquelin.stm32@...il.com>,
        Alexandre Torgue <alexandre.torgue@...s.st.com>,
        linux-stm32@...md-mailman.stormreply.com,
        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        kernel@...gutronix.de
Subject: Re: [PATCH] mfd: stmfx: Improve error message triggered by regulator
 fault in .remove()

On Mon, 07 Feb 2022, Uwe Kleine-König wrote:

> Returning a non-zero value in an i2c remove callback results in the i2c
> core emitting a very generic error message ("remove failed (-ESOMETHING),
> will be ignored") and as the message indicates not further error handling
> is done.
> 
> Instead emit a more specific error message and then return zero in
> .remove().
> 
> The long-term goal is to make the i2c remove prototype return void, making
> all implementations return 0 is preparatory work for this change.
> 
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@...gutronix.de>
> ---
>  drivers/mfd/stmfx.c | 16 +++++++++++-----
>  1 file changed, 11 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/mfd/stmfx.c b/drivers/mfd/stmfx.c
> index e095a3930142..16631c675f2f 100644
> --- a/drivers/mfd/stmfx.c
> +++ b/drivers/mfd/stmfx.c
> @@ -392,17 +392,21 @@ static int stmfx_chip_init(struct i2c_client *client)
>  	return ret;
>  }
>  
> -static int stmfx_chip_exit(struct i2c_client *client)
> +static void stmfx_chip_exit(struct i2c_client *client)
>  {
>  	struct stmfx *stmfx = i2c_get_clientdata(client);
>  
>  	regmap_write(stmfx->map, STMFX_REG_IRQ_SRC_EN, 0);
>  	regmap_write(stmfx->map, STMFX_REG_SYS_CTRL, 0);
>  
> -	if (stmfx->vdd)
> -		return regulator_disable(stmfx->vdd);
> +	if (stmfx->vdd) {
> +		int ret = regulator_disable(stmfx->vdd);
>  
> -	return 0;
> +		if (ret)

Nit: Premise of the patch is fine, but please can you use the standard
function call, check the return value format please.  Something about
this is triggering my OCD! :)

     	int ret;

	ret = regulator_disable(stmfx->vdd);
	if (ret)
		do_thing();

> +			dev_err(&client->dev,
> +				"Failed to disable vdd regulator: %pe\n",
> +				ERR_PTR(ret));
> +	}
>  }
>  
>  static int stmfx_probe(struct i2c_client *client,
> @@ -466,7 +470,9 @@ static int stmfx_remove(struct i2c_client *client)
>  {
>  	stmfx_irq_exit(client);
>  
> -	return stmfx_chip_exit(client);
> +	stmfx_chip_exit(client);
> +
> +	return 0;
>  }
>  
>  #ifdef CONFIG_PM_SLEEP
> 
> base-commit: dcb85f85fa6f142aae1fe86f399d4503d49f2b60

-- 
Lee Jones [李琼斯]
Principal Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
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