Re: [PATCH v2 5/8] rtc: isl12022: implement RTC_VL_READ ioctl

From: Alexandre Belloni
Date: Wed Jun 14 2023 - 09:51:16 EST


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