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Date:   Wed, 14 Jun 2023 15:50:36 +0200
From:   Alexandre Belloni <alexandre.belloni@bootlin.com>
To:     Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc:     Rasmus Villemoes <linux@rasmusvillemoes.dk>,
        Alessandro Zummo <a.zummo@towertech.it>,
        devicetree@vger.kernel.org, Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>, linux-rtc@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 5/8] rtc: isl12022: implement RTC_VL_READ ioctl
Message-ID: <20230614135036a3e049c4@mail.local>
References: <20230612113059.247275-1-linux@rasmusvillemoes.dk>
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 <ZIiJWKBFojAcNCkA@smile.fi.intel.com>
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On 14/06/2023 15:16:14+0300, Andy Shevchenko wrote:
> On Tue, Jun 13, 2023 at 11:26:51PM +0200, Alexandre Belloni wrote:
> > On 13/06/2023 18:20:56+0300, Andy Shevchenko wrote:
> > > On Tue, Jun 13, 2023 at 03:00:07PM +0200, Rasmus Villemoes wrote:
> 
> ...
> 
> > > > +		ret = regmap_read(regmap, ISL12022_REG_SR, &val);
> > > > +		if (ret < 0)
> > > 
> > > I always feel uneasy with ' < 0' — Does positive error makes sense?
> > > Is it even possible? OTOH if the entire driver uses this idiom...
> > > oh well, let's make it consistent.
> > 
> > /**
> >  * regmap_read() - Read a value from a single register
> >  *
> >  * @map: Register map to read from
> >  * @reg: Register to be read from
> >  * @val: Pointer to store read value
> >  *
> >  * A value of zero will be returned on success, a negative errno will
> >  * be returned in error cases.
> >  */
> 
> I'm not sure what you meant by this. Yes, I know that there is no
> possibility that regmap API returns positive value. Do you mean that
> regmap API documentation is unclear?

No, I mean that you'd have to be clearer as to why you are uneasy with a
test for a negative value when the function returns 0 for success and a
negative value for an error. Else, this is pure bullying.

> 
> > > > +			return ret;
> 
> -- 
> With Best Regards,
> Andy Shevchenko
> 
> 

-- 
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com