| Message ID | Y1r8gMR8VBG/4A4P@ubunlion (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | staging: iio: frequency: ad9834: Use div64_ul instead of do_div | expand |
> -----Original Message----- > From: Deepak R Varma <drv@mailo.com> > Sent: Thursday, October 27, 2022 11:48 PM > To: Lars-Peter Clausen <lars@metafoo.de>; Hennerich, Michael > <Michael.Hennerich@analog.com>; Jonathan Cameron <jic23@kernel.org>; > Greg Kroah-Hartman <gregkh@linuxfoundation.org>; linux- > iio@vger.kernel.org; linux-staging@lists.linux.dev; linux- > kernel@vger.kernel.org > Subject: [PATCH] staging: iio: frequency: ad9834: Use div64_ul instead of > do_div > > [External] > > do_div() does a 64-by-32 division. Here the divisor is an unsigned long > which on some platforms is 64 bit wide. So use div64_ul instead of do_div > to avoid a possible truncation. Issue identified using the > coccicheck tool. > > Signed-off-by: Deepak R Varma <drv@mailo.com> > --- Reviewed-by: Nuno Sá <nuno.sa@analog.com>
diff --git a/drivers/staging/iio/frequency/ad9834.c b/drivers/staging/iio/frequency/ad9834.c index 285df0e489a6..3917a76e7976 100644 --- a/drivers/staging/iio/frequency/ad9834.c +++ b/drivers/staging/iio/frequency/ad9834.c @@ -102,8 +102,7 @@ static unsigned int ad9834_calc_freqreg(unsigned long mclk, unsigned long fout) { unsigned long long freqreg = (u64)fout * (u64)BIT(AD9834_FREQ_BITS); - do_div(freqreg, mclk); - return freqreg; + return div64_ul(freqreg, mclk); } static int ad9834_write_frequency(struct ad9834_state *st,
do_div() does a 64-by-32 division. Here the divisor is an unsigned long which on some platforms is 64 bit wide. So use div64_ul instead of do_div to avoid a possible truncation. Issue identified using the coccicheck tool. Signed-off-by: Deepak R Varma <drv@mailo.com> --- drivers/staging/iio/frequency/ad9834.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) -- 2.34.1