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

From	Laxman Dewangan <ldewangan@nvidia.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH] regulator: pwm: Try to avoid voltage error in duty cycle calculation
Date	2016-04-03 13:20 +0200
Message-ID	<rjOeu-2w5-29@gated-at.bofh.it> (permalink)
References	<rj0KK-nf-1@gated-at.bofh.it> <rj145-vD-7@gated-at.bofh.it> <rjx3Y-6F2-7@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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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.

Thread

[PATCH] regulator: pwm: Try to avoid voltage error in duty cycle calculation Laxman Dewangan <ldewangan@nvidia.com> - 2016-03-31 16:10 +0200
  Re: [PATCH] regulator: pwm: Try to avoid voltage error in duty cycle  calculation kbuild test robot <lkp@intel.com> - 2016-04-01 08:30 +0200
    Re: [PATCH] regulator: pwm: Try to avoid voltage error in duty cycle  calculation Laxman Dewangan <ldewangan@nvidia.com> - 2016-04-01 08:50 +0200
      Re: [PATCH] regulator: pwm: Try to avoid voltage error in duty cycle  calculation Mark Brown <broonie@kernel.org> - 2016-04-02 19:00 +0200
        Re: [PATCH] regulator: pwm: Try to avoid voltage error in duty cycle  calculation Laxman Dewangan <ldewangan@nvidia.com> - 2016-04-03 13:20 +0200
          Re: [PATCH] regulator: pwm: Try to avoid voltage error in duty cycle  calculation Mark Brown <broonie@kernel.org> - 2016-04-04 18:30 +0200

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