diff mbox series

[v2,11/11] pwm: Handle .get_state() failures

Message ID 20221130152148.2769768-12-u.kleine-koenig@pengutronix.de
State Accepted
Headers show
Series pwm: Allow .get_state to fail | expand

Commit Message

Uwe Kleine-König Nov. 30, 2022, 3:21 p.m. UTC 
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@pengutronix.de>
---
 drivers/pwm/core.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index 21e1553495ee..855c3885f94b 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -108,8 +108,13 @@  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);
-		trace_pwm_get(pwm, &pwm->state, err);
+		struct pwm_state state;
+
+		err = pwm->chip->ops->get_state(pwm->chip, pwm, &state);
+		trace_pwm_get(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 ||