When disabling, ensure the period write is complete before continuing. This fixes an issue on some devices when the write isn't complete before the panel is turned off but the clock gate is still on.
Signed-off-by: Pascal Roeleven <[email protected]> --- drivers/pwm/pwm-sun4i.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/pwm/pwm-sun4i.c b/drivers/pwm/pwm-sun4i.c index a11d00f96..75250fd4c 100644 --- a/drivers/pwm/pwm-sun4i.c +++ b/drivers/pwm/pwm-sun4i.c @@ -299,6 +299,10 @@ static int sun4i_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, sun4i_pwm_writel(sun4i_pwm, val, PWM_CH_PRD(pwm->hwpwm)); next_period = jiffies + usecs_to_jiffies(cstate.period / 1000 + 1); + /* When disabling, make sure the period register is written first */ + if (!state->enabled && cstate.enabled) + sun4i_pwm_wait(next_period); + if (state->polarity != PWM_POLARITY_NORMAL) ctrl &= ~BIT_CH(PWM_ACT_STATE, pwm->hwpwm); else @@ -320,6 +324,7 @@ static int sun4i_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, return 0; /* We need a full period to elapse before disabling the channel. */ + next_period = jiffies + usecs_to_jiffies(cstate.period / 1000 + 1); sun4i_pwm_wait(next_period); spin_lock(&sun4i_pwm->ctrl_lock); -- 2.20.1 -- You received this message because you are subscribed to the Google Groups "linux-sunxi" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web, visit https://groups.google.com/d/msgid/linux-sunxi/20200317155906.31288-5-dev%40pascalroeleven.nl.
