[PATCH v4 3/3] pwm: core: Set enable state properly on failed call to enable

From: Jonathan Richardson
Date: Tue Dec 30 2014 - 17:43:51 EST


The pwm_enable function didn't clear the enabled bit if a call to a
clients enable function returned an error. The result was that the state
of the pwm core was wrong. Clearing the bit when enable returns an error
ensures the state is properly set.

Signed-off-by: Jonathan Richardson <jonathar@xxxxxxxxxxxx>
---
drivers/pwm/core.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index 966497d..641f6ec 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -457,8 +457,14 @@ EXPORT_SYMBOL_GPL(pwm_set_polarity);
*/
int pwm_enable(struct pwm_device *pwm)
{
- if (pwm && !test_and_set_bit(PWMF_ENABLED, &pwm->flags))
- return pwm->chip->ops->enable(pwm->chip, pwm);
+ int err;
+
+ if (pwm && !test_and_set_bit(PWMF_ENABLED, &pwm->flags)) {
+ err = pwm->chip->ops->enable(pwm->chip, pwm);
+ if (err)
+ clear_bit(PWMF_ENABLED, &pwm->flags);
+ return err;
+ }

return pwm ? 0 : -EINVAL;
}
--
1.7.9.5

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