diff options
Diffstat (limited to 'drivers/pwm/pwm-sifive.c')
| -rw-r--r-- | drivers/pwm/pwm-sifive.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/pwm/pwm-sifive.c b/drivers/pwm/pwm-sifive.c index 400cc91057acf..52a55bae033de 100644 --- a/drivers/pwm/pwm-sifive.c +++ b/drivers/pwm/pwm-sifive.c @@ -184,7 +184,13 @@ static int pwm_sifive_apply(struct pwm_chip *chip, struct pwm_device *pwm, mutex_lock(&ddata->lock); if (state->period != ddata->approx_period) { - if (ddata->user_count != 1) { + /* + * Don't let a 2nd user change the period underneath the 1st user. + * However if ddate->approx_period == 0 this is the first time we set + * any period, so let whoever gets here first set the period so other + * users who agree on the period won't fail. + */ + if (ddata->user_count != 1 && ddata->approx_period) { mutex_unlock(&ddata->lock); ret = -EBUSY; goto exit; |