| Message ID | 85684020f25ce186e3383d6bd67a15c54f930316.1573686315.git.leonard.crestez@nxp.com (mailing list archive) |
|---|---|
| State | Rejected |
| Headers | show |
| Series | PM / devfreq: Don't take lock in devfreq_add_device | expand |
On 11/14/19 8:21 AM, Leonard Crestez wrote: > Right now devfreq_dev_release will print a warning and abort the rest of > the cleanup if the devfreq instance is not part of the global > devfreq_list. But this is a valid scenario, for example it can happen if > the governor can't be found or on any other init error that happens > after device_register. > > Initialize devfreq->node to an empty list head in devfreq_add_device so > that list_del becomes a safe noop inside devfreq_dev_release and we can > continue the rest of the cleanup. > > Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com> > Reviewed-by: Matthias Kaehlcke <mka@chromium.org> > Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com> > --- > drivers/devfreq/devfreq.c | 6 +----- > 1 file changed, 1 insertion(+), 5 deletions(-) > > diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c > index 94fb8e821e12..27af1b95fd23 100644 > --- a/drivers/devfreq/devfreq.c > +++ b/drivers/devfreq/devfreq.c > @@ -635,15 +635,10 @@ static int devfreq_notifier_call(struct notifier_block *nb, unsigned long type, > static void devfreq_dev_release(struct device *dev) > { > struct devfreq *devfreq = to_devfreq(dev); > > mutex_lock(&devfreq_list_lock); > - if (IS_ERR(find_device_devfreq(devfreq->dev.parent))) { > - mutex_unlock(&devfreq_list_lock); > - dev_warn(&devfreq->dev, "releasing devfreq which doesn't exist\n"); > - return; > - } > list_del(&devfreq->node); > mutex_unlock(&devfreq_list_lock); > > if (devfreq->profile->exit) > devfreq->profile->exit(devfreq->dev.parent); > @@ -694,10 +689,11 @@ struct devfreq *devfreq_add_device(struct device *dev, > mutex_init(&devfreq->lock); > mutex_lock(&devfreq->lock); > devfreq->dev.parent = dev; > devfreq->dev.class = devfreq_class; > devfreq->dev.release = devfreq_dev_release; > + INIT_LIST_HEAD(&devfreq->node); > devfreq->profile = profile; > strncpy(devfreq->governor_name, governor_name, DEVFREQ_NAME_LEN); > devfreq->previous_freq = profile->initial_freq; > devfreq->last_status.current_frequency = profile->initial_freq; > devfreq->data = data; > Applied it.
diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index 94fb8e821e12..27af1b95fd23 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -635,15 +635,10 @@ static int devfreq_notifier_call(struct notifier_block *nb, unsigned long type, static void devfreq_dev_release(struct device *dev) { struct devfreq *devfreq = to_devfreq(dev); mutex_lock(&devfreq_list_lock); - if (IS_ERR(find_device_devfreq(devfreq->dev.parent))) { - mutex_unlock(&devfreq_list_lock); - dev_warn(&devfreq->dev, "releasing devfreq which doesn't exist\n"); - return; - } list_del(&devfreq->node); mutex_unlock(&devfreq_list_lock); if (devfreq->profile->exit) devfreq->profile->exit(devfreq->dev.parent); @@ -694,10 +689,11 @@ struct devfreq *devfreq_add_device(struct device *dev, mutex_init(&devfreq->lock); mutex_lock(&devfreq->lock); devfreq->dev.parent = dev; devfreq->dev.class = devfreq_class; devfreq->dev.release = devfreq_dev_release; + INIT_LIST_HEAD(&devfreq->node); devfreq->profile = profile; strncpy(devfreq->governor_name, governor_name, DEVFREQ_NAME_LEN); devfreq->previous_freq = profile->initial_freq; devfreq->last_status.current_frequency = profile->initial_freq; devfreq->data = data;