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pwm: Reduce time the pwm_lock mutex is held in pwmchip_add() 

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>
Link: https://lore.kernel.org/r/20221117211143.3817381-3-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 19:35:10 +01:00 committed by Thierry Reding
parent e51b156b18
commit c8135b5174
1 changed files with 12 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
drivers/pwm/core.c
View File

@ -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);
pwmchip_sysfs_export(chip);
if (!ret)
pwmchip_sysfs_export(chip);
return ret;
return 0;
}
EXPORT_SYMBOL_GPL(pwmchip_add);