PM / devfreq: exynos4: Fix bug of resource leak and code clean on probe()

This patch fix bug about resource leak when happening probe fail and code clean
to add debug message.
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Reviewed-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>

drivers/devfreq/exynos/exynos4_bus.c

@@ -763,19 +763,11 @@ static int exynos4_bus_get_dev_status(struct device *dev,
 	return 0;
 }
 
-static void exynos4_bus_exit(struct device *dev)
-{
-	struct busfreq_data *data = dev_get_drvdata(dev);
-
-	devfreq_unregister_opp_notifier(dev, data->devfreq);
-}
-
 static struct devfreq_dev_profile exynos4_devfreq_profile = {
 	.initial_freq	= 400000,
 	.polling_ms	= 50,
 	.target		= exynos4_bus_target,
 	.get_dev_status	= exynos4_bus_get_dev_status,
-	.exit		= exynos4_bus_exit,
 };
 
 static int exynos4210_init_tables(struct busfreq_data *data)
@@ -1048,8 +1040,11 @@ static int exynos4_busfreq_probe(struct platform_device *pdev)
 		dev_err(dev, "Cannot determine the device id %d\n", data->type);
 		err = -EINVAL;
 	}
-	if (err)
+	if (err) {
+		dev_err(dev, "Cannot initialize busfreq table %d\n",
+			     data->type);
 		return err;
+	}
 
 	data->vdd_int = devm_regulator_get(dev, "vdd_int");
 	if (IS_ERR(data->vdd_int)) {
@@ -1086,23 +1081,39 @@ static int exynos4_busfreq_probe(struct platform_device *pdev)
 	if (IS_ERR(data->devfreq))
 		return PTR_ERR(data->devfreq);
 
-	devfreq_register_opp_notifier(dev, data->devfreq);
+	/* Register opp_notifier for Exynos4 busfreq */
+	err = devfreq_register_opp_notifier(dev, data->devfreq);
+	if (err < 0) {
+		dev_err(dev, "Failed to register opp notifier\n");
+		goto err_notifier_opp;
+	}
 
+	/* Register pm_notifier for Exynos4 busfreq */
 	err = register_pm_notifier(&data->pm_notifier);
 	if (err) {
 		dev_err(dev, "Failed to setup pm notifier\n");
-		devfreq_remove_device(data->devfreq);
-		return err;
+		goto err_notifier_pm;
 	}
 
 	return 0;
+
+err_notifier_pm:
+	devfreq_unregister_opp_notifier(dev, data->devfreq);
+err_notifier_opp:
+	devfreq_remove_device(data->devfreq);
+
+	return err;
 }
 
 static int exynos4_busfreq_remove(struct platform_device *pdev)
 {
 	struct busfreq_data *data = platform_get_drvdata(pdev);
 
+	/* Unregister all of notifier chain */
 	unregister_pm_notifier(&data->pm_notifier);
+	devfreq_unregister_opp_notifier(data->dev, data->devfreq);
+
+	/* Remove devfreq instance */
 	devfreq_remove_device(data->devfreq);
 
 	return 0;