From mboxrd@z Thu Jan 1 00:00:00 1970 From: narmstrong@baylibre.com (Neil Armstrong) Date: Wed, 3 Feb 2016 11:24:55 +0100 Subject: [PATCH 3/4] pwm: omap-dmtimer: round load and match values rather than truncate In-Reply-To: <1454128014-22866-4-git-send-email-drivshin.allworx@gmail.com> References: <1454128014-22866-1-git-send-email-drivshin.allworx@gmail.com> <1454128014-22866-4-git-send-email-drivshin.allworx@gmail.com> Message-ID: <56B1D577.6070808@baylibre.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 01/30/2016 05:26 AM, David Rivshin (Allworx) wrote: > From: David Rivshin > > When converting period and duty_cycle from nanoseconds to fclk cycles, > the error introduced by the integer division can be appreciable, especially > in the case of slow fclk or short period. Use DIV_ROUND_CLOSEST_ULL() so > that the error is kept to +/- 0.5 clock cycles. > > Fixes: 6604c6556db9 ("pwm: Add PWM driver for OMAP using dual-mode timers") > Signed-off-by: David Rivshin OK for me. Acked-by: Neil Armstrong Thanks ! > --- > drivers/pwm/pwm-omap-dmtimer.c | 6 +----- > 1 file changed, 1 insertion(+), 5 deletions(-) > > diff --git a/drivers/pwm/pwm-omap-dmtimer.c b/drivers/pwm/pwm-omap-dmtimer.c > index 103d729..8c9953c 100644 > --- a/drivers/pwm/pwm-omap-dmtimer.c > +++ b/drivers/pwm/pwm-omap-dmtimer.c > @@ -49,11 +49,7 @@ to_pwm_omap_dmtimer_chip(struct pwm_chip *chip) > > static u32 pwm_omap_dmtimer_get_clock_cycles(unsigned long clk_rate, int ns) > { > - u64 c = (u64)clk_rate * ns; > - > - do_div(c, NSEC_PER_SEC); > - > - return c; > + return DIV_ROUND_CLOSEST_ULL((u64)clk_rate * ns, NSEC_PER_SEC); > } > > static void pwm_omap_dmtimer_start(struct pwm_omap_dmtimer_chip *omap) >