i2c: Drop redundant i2c_adapter.list

i2c_adapter.list is superfluous, this list duplicates the one
maintained by the driver core. Drop it.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>

1 files changed, 10 insertions, 14 deletions

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index f75344ac4663..3495ab4035ec 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -34,11 +34,11 @@
 #include <linux/mutex.h>
 #include <linux/completion.h>
 #include <asm/uaccess.h>
+#include <asm/semaphore.h>
 
 #include "i2c-core.h"
 
 
-static LIST_HEAD(adapters);
 static LIST_HEAD(drivers);
 static DEFINE_MUTEX(core_lists);
 static DEFINE_IDR(i2c_adapter_idr);
@@ -331,7 +331,6 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
         INIT_LIST_HEAD(&adap->clients);
 
         mutex_lock(&core_lists);
-        list_add_tail(&adap->list, &adapters);
 
         /* Add the adapter to the driver core.
          * If the parent pointer is not set up,
@@ -368,7 +367,6 @@ out_unlock:
         return res;
 
 out_list:
-        list_del(&adap->list);
         idr_remove(&i2c_adapter_idr, adap->nr);
         goto out_unlock;
 }
@@ -473,7 +471,6 @@ EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter);
 int i2c_del_adapter(struct i2c_adapter *adap)
 {
         struct list_head  *item, *_n;
-        struct i2c_adapter *adap_from_list;
         struct i2c_driver *driver;
         struct i2c_client *client;
         int res = 0;
@@ -481,11 +478,7 @@ int i2c_del_adapter(struct i2c_adapter *adap)
         mutex_lock(&core_lists);
 
         /* First make sure that this adapter was ever added */
-        list_for_each_entry(adap_from_list, &adapters, list) {
-                if (adap_from_list == adap)
-                        break;
-        }
-        if (adap_from_list != adap) {
+        if (idr_find(&i2c_adapter_idr, adap->nr) != adap) {
                 pr_debug("i2c-core: attempting to delete unregistered "
                          "adapter [%s]\n", adap->name);
                 res = -EINVAL;
@@ -529,7 +522,6 @@ int i2c_del_adapter(struct i2c_adapter *adap)
         /* clean up the sysfs representation */
         init_completion(&adap->dev_released);
         device_unregister(&adap->dev);
-        list_del(&adap->list);
 
         /* wait for sysfs to drop all references */
         wait_for_completion(&adap->dev_released);
@@ -592,9 +584,12 @@ int i2c_register_driver(struct module *owner, struct i2c_driver *driver)
         if (driver->attach_adapter) {
                 struct i2c_adapter *adapter;
 
-                list_for_each_entry(adapter, &adapters, list) {
+                down(&i2c_adapter_class.sem);
+                list_for_each_entry(adapter, &i2c_adapter_class.devices,
+                                    dev.node) {
                         driver->attach_adapter(adapter);
                 }
+                up(&i2c_adapter_class.sem);
         }
 
         mutex_unlock(&core_lists);
@@ -609,7 +604,7 @@ EXPORT_SYMBOL(i2c_register_driver);
  */
 void i2c_del_driver(struct i2c_driver *driver)
 {
-        struct list_head   *item1, *item2, *_n;
+        struct list_head   *item2, *_n;
         struct i2c_client  *client;
         struct i2c_adapter *adap;
 
@@ -623,8 +618,8 @@ void i2c_del_driver(struct i2c_driver *driver)
          * attached. If so, detach them to be able to kill the driver
          * afterwards.
          */
-        list_for_each(item1,&adapters) {
-                adap = list_entry(item1, struct i2c_adapter, list);
+        down(&i2c_adapter_class.sem);
+        list_for_each_entry(adap, &i2c_adapter_class.devices, dev.node) {
                 if (driver->detach_adapter) {
                         if (driver->detach_adapter(adap)) {
                                 dev_err(&adap->dev, "detach_adapter failed "
@@ -648,6 +643,7 @@ void i2c_del_driver(struct i2c_driver *driver)
                         }
                 }
         }
+        up(&i2c_adapter_class.sem);
 
  unregister:
         driver_unregister(&driver->driver);