[PATCH 3/3] pwm: Handle .get_state() failures

[Uwe Kleine-König]

This suppresses diagnosis for PWM_DEBUG routines and makes sure that
pwm->state isn't modified in pwm_device_request() if .get_state() fails.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig at pengutronix.de>
---
 drivers/pwm/core.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index 381db04cfa00..421573590613 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -108,9 +108,14 @@ static int pwm_device_request(struct pwm_device *pwm, const char *label)
 	}
 
 	if (pwm->chip->ops->get_state) {
-		err = pwm->chip->ops->get_state(pwm->chip, pwm, &pwm->state);
+		struct pwm_state state;
+
+		err = pwm->chip->ops->get_state(pwm->chip, pwm, &state);
 		trace_pwm_get(pwm, &pwm->state, err);
 
+		if (!err)
+			pwm->state = state;
+
 		if (IS_ENABLED(CONFIG_PWM_DEBUG))
 			pwm->last = pwm->state;
 	}
@@ -459,6 +464,9 @@ static void pwm_apply_state_debug(struct pwm_device *pwm,
 
 	err = chip->ops->get_state(chip, pwm, &s1);
 	trace_pwm_get(pwm, &s1, err);
+	if (err)
+		/* If that failed there isn't much to debug */
+		return;
 
 	/*
 	 * The lowlevel driver either ignored .polarity (which is a bug) or as
@@ -523,6 +531,8 @@ static void pwm_apply_state_debug(struct pwm_device *pwm,
 
 	err = chip->ops->get_state(chip, pwm, last);
 	trace_pwm_get(pwm, last, err);
+	if (err)
+		return;
 
 	/* reapplication of the current state should give an exact match */
 	if (s1.enabled != last->enabled ||
-- 
2.37.2