Re: [PATCH] regulator: pwm: Try to avoid voltage error in duty cycle calculation

[Laxman Dewangan]

On Saturday 02 April 2016 10:23 PM, Mark Brown wrote:
> * PGP Signed by an unknown key
>
> On Fri, Apr 01, 2016 at 12:02:19PM +0530, Laxman Dewangan wrote:
> > On Friday 01 April 2016 11:55 AM, kbuild test robot wrote:
> > > > > pwm-regulator.c:(.text+0x1728d4): undefined reference to `__umoddi3'
> > > > > pwm-regulator.c:(.text+0x1728fd): undefined reference to `__udivdi3'
> > Seems build error is coming from logic
> > u64 req_period
> > unsigned int diff;
> > unsigned int period
> > unsigned int req_diff
> > req_period = req_diff * period;
> > if (req_period % diff == 0)
> > used u64 to avoid overflow in multiplication.
> Yes, you're doing a 64 bit divide so that's kind of expected...

Is there any way to resolve this issue?

Otherwise, need to divide by 100 first for the req_diff to get 10x of mV 
(instead of uV) and then do calculation with unsigned int only. That way 
I can restrict the number to unsigned int.