Messages in this thread | | | Date | Tue, 12 Apr 2016 17:58:20 +0300 | Subject | Re: [PATCH] watchdog: dw_wdt: dont build for avr32 | From | Andy Shevchenko <> |
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On Tue, Apr 12, 2016 at 4:39 PM, Sudip Mukherjee <sudipm.mukherjee@gmail.com> wrote: > On Tuesday 12 April 2016 06:36 PM, Guenter Roeck wrote: >> >> On 04/11/2016 10:51 PM, Sudip Mukherjee wrote: >>> >>> The build of avr32 allmodconfig fails with the error: >>> ERROR: "__avr32_udiv64" [drivers/watchdog/kempld_wdt.ko] undefined! >>> >> This means there is a direct 64 bit divide operation in the driver, >> which we should identify and fix.
This driver will quite likely never be used on AVR32. Do we need to fix this due to some other architectures?
> yes, there is. > > in function: kempld_wdt_set_stage_timeout() > remainder = do_div(stage_timeout64, prescaler);
> Any idea how to fix it?
Not easy, however, prescaler value is ((1 << 21) - 1) which someone might consider as (1 << 21) with lost in precision.
Thus, shift on 20 bits right, add last bit to the value and shift on 1 bit right more.
-- With Best Regards, Andy Shevchenko
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