PM / devfreq: Fix devfreq_notifier_call returning errno

[ Upstream commit e876e710ede23f670494331e062d643928e4142a ]

Notifier callbacks shouldn't return negative errno but one of the
NOTIFY_OK/DONE/BAD values.

The OPP core will ignore return values from notifiers but returning a
value that matches NOTIFY_STOP_MASK will stop the notification chain.

Fix by always returning NOTIFY_OK.
Signed-off-by: NLeonard Crestez <leonard.crestez@nxp.com>
Reviewed-by: NMatthias Kaehlcke <mka@chromium.org>
Reviewed-by: NChanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: NChanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

drivers/devfreq/devfreq.c

@@ -538,26 +538,28 @@ static int devfreq_notifier_call(struct notifier_block *nb, unsigned long type,
 				 void *devp)
 {
 	struct devfreq *devfreq = container_of(nb, struct devfreq, nb);
-	int ret;
+	int err = -EINVAL;
 
 	mutex_lock(&devfreq->lock);
 
 	devfreq->scaling_min_freq = find_available_min_freq(devfreq);
-	if (!devfreq->scaling_min_freq) {
-		mutex_unlock(&devfreq->lock);
-		return -EINVAL;
-	}
+	if (!devfreq->scaling_min_freq)
+		goto out;
 
 	devfreq->scaling_max_freq = find_available_max_freq(devfreq);
-	if (!devfreq->scaling_max_freq) {
-		mutex_unlock(&devfreq->lock);
-		return -EINVAL;
-	}
+	if (!devfreq->scaling_max_freq)
+		goto out;
+
+	err = update_devfreq(devfreq);
 
-	ret = update_devfreq(devfreq);
+out:
 	mutex_unlock(&devfreq->lock);
+	if (err)
+		dev_err(devfreq->dev.parent,
+			"failed to update frequency from OPP notifier (%d)\n",
+			err);
 
-	return ret;
+	return NOTIFY_OK;
 }
 
 /**