[PATCH 1/4] pwm: don't use memcmp to compare struct state variables

["Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>]

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(-)

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) {
-- 
2.20.1