On Tue, Dec 15, 2020 at 11:29:39AM +0000, Paul Barker wrote: > On Tue, 15 Dec 2020 at 09:23, Uwe Kleine-König > <u.kleine-koenig@xxxxxxxxxxxxxx> wrote: > > > > With MAX_PWM being defined to 255 the code > > > > unsigned long period; > > ... > > period = ctx->pwm->args.period; > > state.duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM); > > Reviewing this I noticed that in pwm_fan_resume() we use > DIV_ROUND_UP_ULL for what looks like essentially the same calculation. After my second patch this isn't true any more. With it applied __set_pwm is the only place in the driver that calculates this stuff. > Could we just switch this line to DIV_ROUND_UP_ULL instead? Yes that would work, but actually I don't expect someone specifiying a period big enough to justify the additional overhead of a 64 bit division. Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | https://www.pengutronix.de/ |
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