[PATCH v2] acerhdf: fix resource reclaim in error path

[Axel Lin <axel.lin@gmail.com>]

This patch fix resource reclaim in below cases:
1. acerhdf_register_platform() does not properly handle
   platform_device_alloc() failure and platform_device_add() failure
   This patch adds error handing for acerhdf_register_platform().
2. acerhdf_register_platform() return err with acerhdf_dev == NULL.
   as a result, acerhdf_unregister_platform() does not do resource
   reclaim in acerhdf_init() error path.
   This patch adds error handing for acerhdf_register_platform(),
   thus correct the error handing path in acerhdf_init().
   goto out_err instead of err_unreg if acerhdf_register_platform() fail.
3. platform_device_del() should only used in error handling.
   Current implementation missed a platform_device_put() in acerhdf_exit.
   This patch fixes it by using platform_device_unregister() instead of
   platform_device_del() in acerhdf_unregister_platform.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
---
 drivers/platform/x86/acerhdf.c |   23 ++++++++++++++++-------
 1 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/drivers/platform/x86/acerhdf.c b/drivers/platform/x86/acerhdf.c
index 7b2384d..d9f5ebb 100644
--- a/drivers/platform/x86/acerhdf.c
+++ b/drivers/platform/x86/acerhdf.c
@@ -579,17 +579,26 @@ static int acerhdf_register_platform(void)
 		return err;
 
 	acerhdf_dev = platform_device_alloc("acerhdf", -1);
-	platform_device_add(acerhdf_dev);
+	if (!acerhdf_dev) {
+		err = -ENOMEM;
+		goto err_device_alloc;
+	}
+	err = platform_device_add(acerhdf_dev);
+	if (err)
+		goto err_device_add;
 
 	return 0;
+
+err_device_add:
+	platform_device_put(acerhdf_dev);
+err_device_alloc:
+	platform_driver_unregister(&acerhdf_driver);
+	return err;
 }
 
 static void acerhdf_unregister_platform(void)
 {
-	if (!acerhdf_dev)
-		return;
-
-	platform_device_del(acerhdf_dev);
+	platform_device_unregister(acerhdf_dev);
 	platform_driver_unregister(&acerhdf_driver);
 }
 
@@ -633,7 +642,7 @@ static int __init acerhdf_init(void)
 
 	err = acerhdf_register_platform();
 	if (err)
-		goto err_unreg;
+		goto out_err;
 
 	err = acerhdf_register_thermal();
 	if (err)
@@ -646,7 +655,7 @@ err_unreg:
 	acerhdf_unregister_platform();
 
 out_err:
-	return -ENODEV;
+	return err;
 }
 
 static void __exit acerhdf_exit(void)
-- 
1.5.4.3