| Message ID | 20181119195637.16341-1-u.kleine-koenig@pengutronix.de |
|---|---|
| State | Superseded |
| Headers | show |
| Series | pwm: don't use memcmp to compare struct state variables | expand |
diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c index 1581f6ab1b1f..253a459fe0d8 100644 --- a/drivers/pwm/core.c +++ b/drivers/pwm/core.c @@ -472,7 +472,10 @@ int pwm_apply_state(struct pwm_device *pwm, struct pwm_state *state) state->duty_cycle > state->period) return -EINVAL; - if (!memcmp(state, &pwm->state, sizeof(*state))) + if (state->period == pwm->state.period && + state->duty_cycle == pwm->state.duty_cycle && + state->polarity == pwm->state.polarity && + state->enabled == pwm->state.enabled) return 0; if (pwm->chip->ops->apply) {
Given that struct pwm_state is sparse (at least on some platforms) variables of this type might represent the same state because all fields are pairwise identical but still memcmp returns a difference because some of the unused bits are different. To prevent surprises compare member by member instead of the whole occupied memory. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> --- drivers/pwm/core.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)