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

From: Uwe Kleine-König
Date: Tue Nov 15 2022 - 16:15:58 EST


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.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
---
drivers/pwm/core.c | 27 ++++++++++++---------------
1 file changed, 12 insertions(+), 15 deletions(-)

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);

--
2.38.1