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authorUwe Kleine-König <u.kleine-koenig@pengutronix.de>2022-12-02 19:35:36 +0100
committerThierry Reding <thierry.reding@gmail.com>2022-12-06 12:46:29 +0100
commitc73a3107624ddc305483ced13deca9ce8a073783 (patch)
tree16ea7566a4aa42fd60f752b86e32f840964aaedf /drivers/pwm
parent500f879843adf329281e418d302e1ad40baa26c3 (diff)
pwm: Handle .get_state() failures
This suppresses diagnosis for PWM_DEBUG routines and makes sure that pwm->state isn't modified in pwm_device_request() if .get_state() fails. Acked-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20221130152148.2769768-12-u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Diffstat (limited to 'drivers/pwm')
-rw-r--r--drivers/pwm/core.c14
1 files changed, 12 insertions, 2 deletions
diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index 61d15510fdd7..e01147f66e15 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -115,8 +115,13 @@ 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;
@@ -460,6 +465,9 @@ 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
@@ -524,6 +532,8 @@ 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 ||