Messages in this thread | | | From | Andy Shevchenko <> | Date | Tue, 27 Feb 2018 17:54:00 +0200 | Subject | Re: [PATCH v2 3/3] gpio: Add Spreadtrum PMIC EIC driver support |
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On Tue, Feb 27, 2018 at 4:35 AM, Baolin Wang <baolin.wang@linaro.org> wrote: > On 26 February 2018 at 20:02, Andy Shevchenko <andy.shevchenko@gmail.com> wrote: >> On Mon, Feb 26, 2018 at 5:01 AM, Baolin Wang <baolin.wang@linaro.org> wrote: >>> On 25 February 2018 at 20:19, Andy Shevchenko <andy.shevchenko@gmail.com> wrote:
>>>>> + for (n = 0; n < chip->ngpio; n++) { >>>>> + if (!(BIT(n) & val)) >>>> >>>> for_each_set_bit(). >>>> >>>> At some point you may need just to go across lib/ in the kernel and >>>> see what we have there. >>> >>> I've considered the for_each_set_bit(), it need one 'unsigned long' >>> type parameter, but we get the value from regmap is 'u32' type. So we >>> need one extra conversion from 'u32' to 'unsigned long' like: >>> >>> unsigned long reg = val; >>> >>> for_each_set_bit(n, ®, chip->ngpio) { >>> ....... >>> } >>> >>> If you like this conversion, then I can change to use >>> for_each_set_bit(). Thanks. >> >> Wouldn't it work like >> >> unsigned long val; >> >> ...regmap_read(..., &val); >> >> ? > > It can not work, regmap_read() expects 'unsigned int *'.
Ah, OK, than the temporary variable is a left approach.
> But I can > convert it like this: > > for_each_set_bit(n, (unsigned long *)&val, chip->ngpio) { > ....... > }
No, this is a boilerplate for static analyzers and definitely UB.
-- With Best Regards, Andy Shevchenko
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