Re: [PATCH 6/6] i2c: Make remove callback return void - Uwe Kleine-König

From: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>
To: Jean Delvare <jdelvare@suse.de>
Cc: Wolfram Sang <wsa@kernel.org>,
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Subject: Re: [PATCH 6/6] i2c: Make remove callback return void
Date: Tue, 5 Jul 2022 12:36:15 +0200	[thread overview]
Message-ID: <20220705103615.ceeq7rku53x743ps@pengutronix.de> (raw)
In-Reply-To: <20220705120852.049dc235@endymion.delvare>

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On Tue, Jul 05, 2022 at 12:08:52PM +0200, Jean Delvare wrote:
> On Tue, 28 Jun 2022 16:03:12 +0200, Uwe Kleine-König wrote:
> > From: Uwe Kleine-König <uwe@kleine-koenig.org>
> > 
> > The value returned by an i2c driver's remove function is mostly ignored.
> > (Only an error message is printed if the value is non-zero that the
> > error is ignored.)
> > 
> > So change the prototype of the remove function to return no value. This
> > way driver authors are not tempted to assume that passing an error to
> > the upper layer is a good idea. All drivers are adapted accordingly.
> > There is no intended change of behaviour, all callbacks were prepared to
> > return 0 before.
> > 
> > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> > ---
> 
> That's a huge change for a relatively small benefit, but if this is
> approved by the I2C core maintainer then fine with me. For:

Agreed, it's huge. The benefit isn't really measureable, the motivation
is to improve the situation for driver authors who with the change
cannot make wrong assumptions about what to return in .remove(). During
the preparation this uncovered a few bugs. See for example
bbc126ae381cf0a27822c1f822d0aeed74cc40d9.

> >  drivers/hwmon/adc128d818.c                                | 4 +---
> >  drivers/hwmon/adt7470.c                                   | 3 +--
> >  drivers/hwmon/asb100.c                                    | 6 ++----
> >  drivers/hwmon/asc7621.c                                   | 4 +---
> >  drivers/hwmon/dme1737.c                                   | 4 +---
> >  drivers/hwmon/f75375s.c                                   | 5 ++---
> >  drivers/hwmon/fschmd.c                                    | 6 ++----
> >  drivers/hwmon/ftsteutates.c                               | 3 +--
> >  drivers/hwmon/ina209.c                                    | 4 +---
> >  drivers/hwmon/ina3221.c                                   | 4 +---
> >  drivers/hwmon/jc42.c                                      | 3 +--
> >  drivers/hwmon/mcp3021.c                                   | 4 +---
> >  drivers/hwmon/occ/p8_i2c.c                                | 4 +---
> >  drivers/hwmon/pcf8591.c                                   | 3 +--
> >  drivers/hwmon/smm665.c                                    | 3 +--
> >  drivers/hwmon/tps23861.c                                  | 4 +---
> >  drivers/hwmon/w83781d.c                                   | 4 +---
> >  drivers/hwmon/w83791d.c                                   | 6 ++----
> >  drivers/hwmon/w83792d.c                                   | 6 ++----
> >  drivers/hwmon/w83793.c                                    | 6 ++----
> >  drivers/hwmon/w83795.c                                    | 4 +---
> >  drivers/hwmon/w83l785ts.c                                 | 6 ++----
> >  drivers/i2c/i2c-core-base.c                               | 6 +-----
> >  drivers/i2c/i2c-slave-eeprom.c                            | 4 +---
> >  drivers/i2c/i2c-slave-testunit.c                          | 3 +--
> >  drivers/i2c/i2c-smbus.c                                   | 3 +--
> >  drivers/i2c/muxes/i2c-mux-ltc4306.c                       | 4 +---
> >  drivers/i2c/muxes/i2c-mux-pca9541.c                       | 3 +--
> >  drivers/i2c/muxes/i2c-mux-pca954x.c                       | 3 +--
> 
> Reviewed-by: Jean Delvare <jdelvare@suse.de>

Thanks
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |

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