Messages in this thread Patch in this message | | | Date | Wed, 17 Nov 2021 12:25:59 +0100 | From | Uwe Kleine-König <> | Subject | Re: [PATCH] pwm: rcar: Use div64_ul instead of do_div |
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On Wed, Nov 17, 2021 at 02:08:54AM +0000, cgel.zte@gmail.com wrote: > From: Changcheng Deng <deng.changcheng@zte.com.cn> > > do_div() does a 64-by-32 division. If the divisor is unsigned long, using > div64_ul can avoid truncation to 32-bit. > > Reported-by: Zeal Robot <zealci@zte.com.cn> > Signed-off-by: Changcheng Deng <deng.changcheng@zte.com.cn> > --- > drivers/pwm/pwm-rcar.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/pwm/pwm-rcar.c b/drivers/pwm/pwm-rcar.c > index b437192380e2..fb475c188e1e 100644 > --- a/drivers/pwm/pwm-rcar.c > +++ b/drivers/pwm/pwm-rcar.c > @@ -111,7 +111,7 @@ static int rcar_pwm_set_counter(struct rcar_pwm_chip *rp, int div, int duty_ns, > u32 cyc, ph; > > one_cycle = (unsigned long long)NSEC_PER_SEC * 100ULL * (1 << div); > - do_div(one_cycle, clk_rate); > + div64_ul(one_cycle, clk_rate);
Same problem as with the atmel-hlcdc patch: The calling convention of do_div and div64_ul are different and with the proposed patch the result of the division is unused.
Best regards Uwe
-- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | https://www.pengutronix.de/ | [unhandled content-type:application/pgp-signature] | |