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

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Message-ID: <YgpndOadzi0+5jQr@google.com>
Date:   Mon, 14 Feb 2022 14:30:12 +0000
From:   Lee Jones <lee.jones@...aro.org>
To:     Uwe Kleine-König 
        <u.kleine-koenig@...gutronix.de>
Cc:     Maxime Coquelin <mcoquelin.stm32@...il.com>,
        linux-kernel@...r.kernel.org,
        Alexandre Torgue <alexandre.torgue@...s.st.com>,
        kernel@...gutronix.de, linux-stm32@...md-mailman.stormreply.com,
        linux-arm-kernel@...ts.infradead.org
Subject: Re: [PATCH] mfd: stmfx: Improve error message triggered by regulator
 fault in .remove()

On Mon, 14 Feb 2022, Uwe Kleine-König wrote:

> On Mon, Feb 14, 2022 at 01:46:37PM +0000, Lee Jones wrote:
> > 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();
> 
> Not sure I understand you correctly. Do you want just:
> 
>  	regmap_write(stmfx->map, STMFX_REG_SYS_CTRL, 0);
>  
>  	if (stmfx->vdd) {
> -		int ret = regulator_disable(stmfx->vdd);
> +		int ret;
> +
> +		ret = regulator_disable(stmfx->vdd);
>  		if (ret)
>  ...
> 
> squashed into the patch?

Effectively, yes please.

The diff would look like:

> > > -	if (stmfx->vdd)
> > > -		return regulator_disable(stmfx->vdd);
> > > +	if (stmfx->vdd) {
> > > +		int ret;
> > > +
> > > +		ret = regulator_disable(stmfx->vdd);
> > > -
> > > -	return 0;
> > > +		if (ret)

Thanks.

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