1 files changed, 24 insertions, 21 deletions

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index bea4c5021d26..d231f683f576 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -425,14 +425,14 @@ static int __i2c_check_addr_busy(struct device *dev, void *addrp)
 /* walk up mux tree */
 static int i2c_check_mux_parents(struct i2c_adapter *adapter, int addr)
 {
+        struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
         int result;
 
         result = device_for_each_child(&adapter->dev, &addr,
                                         __i2c_check_addr_busy);
 
-        if (!result && i2c_parent_is_i2c_adapter(adapter))
-                result = i2c_check_mux_parents(
-                                    to_i2c_adapter(adapter->dev.parent), addr);
+        if (!result && parent)
+                result = i2c_check_mux_parents(parent, addr);
 
         return result;
 }
@@ -453,11 +453,11 @@ static int i2c_check_mux_children(struct device *dev, void *addrp)
 
 static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr)
 {
+        struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
         int result = 0;
 
-        if (i2c_parent_is_i2c_adapter(adapter))
-                result = i2c_check_mux_parents(
-                                    to_i2c_adapter(adapter->dev.parent), addr);
+        if (parent)
+                result = i2c_check_mux_parents(parent, addr);
 
         if (!result)
                 result = device_for_each_child(&adapter->dev, &addr,
@@ -472,8 +472,10 @@ static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr)
  */
 void i2c_lock_adapter(struct i2c_adapter *adapter)
 {
-        if (i2c_parent_is_i2c_adapter(adapter))
-                i2c_lock_adapter(to_i2c_adapter(adapter->dev.parent));
+        struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
+
+        if (parent)
+                i2c_lock_adapter(parent);
         else
                 rt_mutex_lock(&adapter->bus_lock);
 }
@@ -485,8 +487,10 @@ EXPORT_SYMBOL_GPL(i2c_lock_adapter);
  */
 static int i2c_trylock_adapter(struct i2c_adapter *adapter)
 {
-        if (i2c_parent_is_i2c_adapter(adapter))
-                return i2c_trylock_adapter(to_i2c_adapter(adapter->dev.parent));
+        struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
+
+        if (parent)
+                return i2c_trylock_adapter(parent);
         else
                 return rt_mutex_trylock(&adapter->bus_lock);
 }
@@ -497,8 +501,10 @@ static int i2c_trylock_adapter(struct i2c_adapter *adapter)
  */
 void i2c_unlock_adapter(struct i2c_adapter *adapter)
 {
-        if (i2c_parent_is_i2c_adapter(adapter))
-                i2c_unlock_adapter(to_i2c_adapter(adapter->dev.parent));
+        struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter);
+
+        if (parent)
+                i2c_unlock_adapter(parent);
         else
                 rt_mutex_unlock(&adapter->bus_lock);
 }
@@ -677,8 +683,6 @@ i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr,
         char *blank, end;
         int res;
 
-        dev_warn(dev, "The new_device interface is still experimental "
-                 "and may change in a near future\n");
         memset(&info, 0, sizeof(struct i2c_board_info));
 
         blank = strchr(buf, ' ');
@@ -1504,26 +1508,25 @@ static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver)
         if (!driver->detect || !address_list)
                 return 0;
 
+        /* Stop here if the classes do not match */
+        if (!(adapter->class & driver->class))
+                return 0;
+
         /* Set up a temporary client to help detect callback */
         temp_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL);
         if (!temp_client)
                 return -ENOMEM;
         temp_client->adapter = adapter;
 
-        /* Stop here if the classes do not match */
-        if (!(adapter->class & driver->class))
-                goto exit_free;
-
         for (i = 0; address_list[i] != I2C_CLIENT_END; i += 1) {
                 dev_dbg(&adapter->dev, "found normal entry for adapter %d, "
                         "addr 0x%02x\n", adap_id, address_list[i]);
                 temp_client->addr = address_list[i];
                 err = i2c_detect_address(temp_client, driver);
-                if (err)
-                        goto exit_free;
+                if (unlikely(err))
+                        break;
         }
 
- exit_free:
         kfree(temp_client);
         return err;
 }