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pwm: Handle .get_state() failures

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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>
This commit is contained in:
Uwe Kleine-König 2022-12-02 19:35:36 +01:00 committed by Thierry Reding
parent 500f879843
commit c73a310762
1 changed files with 12 additions and 2 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

14
drivers/pwm/core.c
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@ -115,8 +115,13 @@ static int pwm_device_request(struct pwm_device *pwm, const char *label)
} }
if (pwm->chip->ops->get_state) { if (pwm->chip->ops->get_state) {
err = pwm->chip->ops->get_state(pwm->chip, pwm, &pwm->state); struct pwm_state state;
trace_pwm_get(pwm, &pwm->state, err);
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)) if (IS_ENABLED(CONFIG_PWM_DEBUG))
pwm->last = pwm->state; 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); err = chip->ops->get_state(chip, pwm, &s1);
trace_pwm_get(pwm, &s1, err); 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 * 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); err = chip->ops->get_state(chip, pwm, last);
trace_pwm_get(pwm, last, err); trace_pwm_get(pwm, last, err);
if (err)
return;
/* reapplication of the current state should give an exact match */ /* reapplication of the current state should give an exact match */
if (s1.enabled != last->enabled || if (s1.enabled != last->enabled ||