Messages in this thread | | | From | Guillermo Rodriguez Garcia <> | Date | Thu, 9 Jun 2016 18:36:31 +0200 | Subject | Re: [PATCH] pwm: atmel: Fix disabling of PWM channels |
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Hello,
Any comments on this patch?
Guillermo
2016-05-13 13:09 GMT+02:00 Guillermo Rodriguez <guille.rodriguez@gmail.com>: > When disabling a PWM channel, the PWM clock was being stopped > immediately after writing to PWM_DIS. As a result, the disabling > of the PWM channel did not complete properly, and the PWM output > might be left at the wrong level. > > Fix this by waiting for the channel to be effectively disabled > (by checking the PWM_SR register) before disabling the clock. > > Signed-off-by: Guillermo Rodriguez <guille.rodriguez@gmail.com> > --- > drivers/pwm/pwm-atmel.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/drivers/pwm/pwm-atmel.c b/drivers/pwm/pwm-atmel.c > index 0e4bd4e..a714434 100644 > --- a/drivers/pwm/pwm-atmel.c > +++ b/drivers/pwm/pwm-atmel.c > @@ -271,6 +271,16 @@ static void atmel_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) > mutex_unlock(&atmel_pwm->isr_lock); > atmel_pwm_writel(atmel_pwm, PWM_DIS, 1 << pwm->hwpwm); > > + /* > + * Wait for the PWM channel disable operation to be effective before > + * stopping the clock. > + */ > + timeout = jiffies + 2 * HZ; > + while ((atmel_pwm_readl(atmel_pwm, PWM_SR)& (1 << pwm->hwpwm)) && > + time_before(jiffies, timeout)) { > + usleep_range(10, 100); > + } > + > clk_disable(atmel_pwm->clk); > } > > -- > 1.7.9.5 >
-- Guillermo Rodriguez Garcia guille.rodriguez@gmail.com
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