| Message ID | 1454128014-22866-4-git-send-email-drivshin.allworx@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 01/30/2016 05:26 AM, David Rivshin (Allworx) wrote: > From: David Rivshin <drivshin@allworx.com> > > 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 <drivshin@allworx.com> OK for me. Acked-by: Neil Armstrong <narmstrong@baylibre.com> 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) >
On Fri, Jan 29, 2016 at 11:26:53PM -0500, David Rivshin (Allworx) wrote: > From: David Rivshin <drivshin@allworx.com> > > 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 <drivshin@allworx.com> > --- > drivers/pwm/pwm-omap-dmtimer.c | 6 +----- > 1 file changed, 1 insertion(+), 5 deletions(-) Applied, thanks. Thierry
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)