Messages in this thread | | | Subject | Re: [PATCH v9 4/4] rtc: ds1307: add frequency_test_enable sysfs attribute to check tick on m41txx | From | Giulio Benetti <> | Date | Fri, 20 Jul 2018 15:06:10 +0200 |
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Il 20/07/2018 14:53, Andy Shevchenko ha scritto: > On Thu, Jul 19, 2018 at 9:19 PM, Giulio Benetti > <giulio.benetti@micronovasrl.com> wrote: >> Hi Andy, >> >> Il 18/07/2018 18:26, Andy Shevchenko ha scritto: >>> >>> On Wed, Jul 18, 2018 at 5:06 PM, Giulio Benetti >>> <giulio.benetti@micronovasrl.com> wrote: >>> >>>>>> + int ret; >>>>>> + >>>>>> + ret = kstrtobool(buf, &freq_test_en); >>>>>> + if (ret == -EINVAL) { >>> >>> >>>>> What kind of other error code you may expect and why they are not >>>>> considered as no error? >>> >>> >>>> According to documentation, kstrtobool can only fail with -EINVAL. >>>> See: >>>> https://elixir.bootlin.com/linux/v4.18-rc5/source/lib/kstrtox.c#L332 >>> >>> >>> That's correct. So, what do you want to show by explicitly mentioned >>> an error code in the condition? >>> >> >> So you mean I should check for negative values instead of specific error, >> right? > > Learn from the existing code. > > As you found kstrtobool() returns either 0 (no error), or -EINVAL (the > only possible error code for now). > Checking ret for non-zero is enough. > Thus, > > if (ret) { > ... > return ret; > } > > should do a job. >
Oh, I was pretty sure I've found an example of kstrtobool() in the way I've used, instead no. Thanks for pointing me. I correct it.
Best regards Giulio
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