diff mbox series

[v2,2/4] pwm: Reduce time the pwm_lock mutex is held in pwmchip_add()

Message ID 20221117211143.3817381-3-u.kleine-koenig@pengutronix.de
State Accepted
Headers show
Series pwm: Some refactoring of pwmchip_add() | expand

Commit Message

Uwe Kleine-König Nov. 17, 2022, 9:11 p.m. UTC 
This simplifies error handling as the need for goto error handling goes
away and at the end of the function the code can be simplified as this
code isn't used in the error case any more.

Now memory allocation and the call to of_pwmchip_add() are done without
holding the lock. Both don't access the data structures protected by
&pwm_lock.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 drivers/pwm/core.c | 27 ++++++++++++---------------
 1 file changed, 12 insertions(+), 15 deletions(-)
diff mbox series

Patch

diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c
index ebe06efe9de5..2338119a09d8 100644
--- a/drivers/pwm/core.c
+++ b/drivers/pwm/core.c
@@ -272,20 +272,21 @@  int pwmchip_add(struct pwm_chip *chip)
 	if (!pwm_ops_check(chip))
 		return -EINVAL;
 
+	chip->pwms = kcalloc(chip->npwm, sizeof(*pwm), GFP_KERNEL);
+	if (!chip->pwms)
+		return -ENOMEM;
+
 	mutex_lock(&pwm_lock);
 
 	ret = alloc_pwms(chip->npwm);
-	if (ret < 0)
-		goto out;
+	if (ret < 0) {
+		mutex_unlock(&pwm_lock);
+		kfree(chip->pwms);
+		return ret;
+	}
 
 	chip->base = ret;
 
-	chip->pwms = kcalloc(chip->npwm, sizeof(*pwm), GFP_KERNEL);
-	if (!chip->pwms) {
-		ret = -ENOMEM;
-		goto out;
-	}
-
 	for (i = 0; i < chip->npwm; i++) {
 		pwm = &chip->pwms[i];
 
@@ -301,18 +302,14 @@  int pwmchip_add(struct pwm_chip *chip)
 	INIT_LIST_HEAD(&chip->list);
 	list_add(&chip->list, &pwm_chips);
 
-	ret = 0;
+	mutex_unlock(&pwm_lock);
 
 	if (IS_ENABLED(CONFIG_OF))
 		of_pwmchip_add(chip);
 
-out:
-	mutex_unlock(&pwm_lock);
-
-	if (!ret)
-		pwmchip_sysfs_export(chip);
+	pwmchip_sysfs_export(chip);
 
-	return ret;
+	return 0;
 }
 EXPORT_SYMBOL_GPL(pwmchip_add);