Commit 309b32fb authored Jan 07, 2019 by Uwe Kleine-König Committed by Thierry Reding Jan 10, 2019

pwm: Don't use memcmp() to compare state variables



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>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

parent bfeffd15

drivers/pwm/core.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -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) {