Re: [PATCH v4 1/3] mfd: Add new mfd device TPS68470

From: Andy Shevchenko
Date: Tue Jul 25 2017 - 06:29:22 EST


On Tue, Jul 25, 2017 at 12:10 PM, Lee Jones <lee.jones@xxxxxxxxxx> wrote:
> On Fri, 21 Jul 2017, Mani, Rajmohan wrote:
>> > On Wed, 19 Jul 2017, Rajmohan Mani wrote:

>> > > + /* Force software reset */
>> > > + ret = regmap_write(regmap, TPS68470_REG_RESET,
>> > TPS68470_REG_RESET_MASK);
>> > > + if (ret < 0)
>> >
>> > Will 'if (!ret)' do?
>> >
>>
>> We intend to check error conditions and bail out. So, if (ret < 0) works for this.
>
> Yes, 'if (!ret)' does that too.

Did you mean

if (ret)
return ret;

?

I briefly checked few ->read() and ->write() implementations and
didn't find any evidence of positive numbers that can be returned.
Documentation (kernel doc) doesn't shed a light on that. So, to me it
sounds unspecified.

So, for now (until documentation will be fixed) I would rely on
if (ret < 0)


--
With Best Regards,
Andy Shevchenko