1 files changed, 18 insertions, 12 deletions

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index bea4c5021d26..40e563de0508 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);
 }