[PATCH v6 4/4] pwm: core: Set enable state properly on failed call to enable

[Jonathan Richardson <jonathar@broadcom.com>]

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.

Tested-by: Jonathan Richardson <jonathar@broadcom.com>
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Jonathan Richardson <jonathar@broadcom.com>
---
 drivers/pwm/core.c |   16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index c0a550b..793add5 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -477,10 +477,20 @@ 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)
+		return -EINVAL;
+
+	if (!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;
+	return 0;
 }
 EXPORT_SYMBOL_GPL(pwm_enable);
 
-- 
1.7.9.5