Re: [PATCH v5 2/2] iio: proximity: Add driver support for vcnl3020 proximity sensor

From: Ivan Mikhaylov <i.mikhaylov@yadro.com>
To: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Jonathan Cameron <jic23@kernel.org>,
	Hartmut Knaack <knaack.h@gmx.de>,
	Lars-Peter Clausen <lars@metafoo.de>,
	Peter Meerwald-Stadler <pmeerw@pmeerw.net>,
	linux-iio <linux-iio@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	devicetree <devicetree@vger.kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Rob Herring <robh+dt@kernel.org>
Subject: Re: [PATCH v5 2/2] iio: proximity: Add driver support for vcnl3020 proximity sensor
Date: Tue, 31 Mar 2020 19:56:18 +0300	[thread overview]
Message-ID: <86186f02c630a05cf7254a38e0f15d726e2f440b.camel@yadro.com> (raw)
In-Reply-To: <CAHp75VexS-iVeDXsCFqgzCKokgzzeH=BFtUqOJdY+kS8O6B9bw@mail.gmail.com>

On Tue, 2020-03-31 at 14:00 +0300, Andy Shevchenko wrote:
> > > Why not to use standard pattern, i.e.
> > > 
> > >   if (rc)
> > >     return rc;
> > >   ...
> > >   rc = regmap_write(...);
> > > 
> > > ?
> > 
> > Optional parameter. There exists a lot of ways to do it:
> 
> I'm simple reading the code. And I believe the above I suggested is
> cleaner equivalent.
> Is it?
> 
> > rc = device_property_read_u32(dev, "milliamp", &led_current);
> > rc = regmap_write(regmap, VCNL_LED_CURRENT, (!rc) : led_current ? 0);
> 
> This seems not equal to above.

Yes, it is not equal. Error will be returned in case of non existent parameter
in vcnl3020_init but parameter is optional. rc shouldn't be checked or should
return 0 with your suggestion.

rc = device_property_read_u32(...);
if (rc)
	return 0;
rc = regmap_write(...);
if (rc)
	dev_err(...);
return rc;