1 files changed, 40 insertions, 23 deletions

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 3202a86f420e..c2258a51fe0c 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -40,12 +40,11 @@
 #include "i2c-core.h"
 
 
-/* core_lock protects i2c_adapter_idr, userspace_devices, and guarantees
+/* core_lock protects i2c_adapter_idr, and guarantees
    that device detection, deletion of detected devices, and attach_adapter
    and detach_adapter calls are serialized */
 static DEFINE_MUTEX(core_lock);
 static DEFINE_IDR(i2c_adapter_idr);
-static LIST_HEAD(userspace_devices);
 
 static struct device_type i2c_client_type;
 static int i2c_check_addr(struct i2c_adapter *adapter, int addr);
@@ -117,8 +116,10 @@ static int i2c_device_probe(struct device *dev)
         dev_dbg(dev, "probe\n");
 
         status = driver->probe(client, i2c_match_id(driver->id_table, client));
-        if (status)
+        if (status) {
                 client->driver = NULL;
+                i2c_set_clientdata(client, NULL);
+        }
         return status;
 }
 
@@ -139,8 +140,10 @@ static int i2c_device_remove(struct device *dev)
                 dev->driver = NULL;
                 status = 0;
         }
-        if (status == 0)
+        if (status == 0) {
                 client->driver = NULL;
+                i2c_set_clientdata(client, NULL);
+        }
         return status;
 }
 
@@ -538,9 +541,9 @@ i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr,
                 return -EEXIST;
 
         /* Keep track of the added device */
-        mutex_lock(&core_lock);
-        list_add_tail(&client->detected, &userspace_devices);
-        mutex_unlock(&core_lock);
+        i2c_lock_adapter(adap);
+        list_add_tail(&client->detected, &adap->userspace_clients);
+        i2c_unlock_adapter(adap);
         dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device",
                  info.type, info.addr);
 
@@ -579,9 +582,10 @@ i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr,
 
         /* Make sure the device was added through sysfs */
         res = -ENOENT;
-        mutex_lock(&core_lock);
-        list_for_each_entry_safe(client, next, &userspace_devices, detected) {
-                if (client->addr == addr && client->adapter == adap) {
+        i2c_lock_adapter(adap);
+        list_for_each_entry_safe(client, next, &adap->userspace_clients,
+                                 detected) {
+                if (client->addr == addr) {
                         dev_info(dev, "%s: Deleting device %s at 0x%02hx\n",
                                  "delete_device", client->name, client->addr);
 
@@ -591,7 +595,7 @@ i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr,
                         break;
                 }
         }
-        mutex_unlock(&core_lock);
+        i2c_unlock_adapter(adap);
 
         if (res < 0)
                 dev_err(dev, "%s: Can't find device in list\n",
@@ -673,6 +677,7 @@ static int i2c_register_adapter(struct i2c_adapter *adap)
         }
 
         rt_mutex_init(&adap->bus_lock);
+        INIT_LIST_HEAD(&adap->userspace_clients);
 
         /* Set default timeout to 1 second if not already set */
         if (adap->timeout == 0)
@@ -875,14 +880,15 @@ int i2c_del_adapter(struct i2c_adapter *adap)
                 return res;
 
         /* Remove devices instantiated from sysfs */
-        list_for_each_entry_safe(client, next, &userspace_devices, detected) {
-                if (client->adapter == adap) {
-                        dev_dbg(&adap->dev, "Removing %s at 0x%x\n",
-                                client->name, client->addr);
-                        list_del(&client->detected);
-                        i2c_unregister_device(client);
-                }
+        i2c_lock_adapter(adap);
+        list_for_each_entry_safe(client, next, &adap->userspace_clients,
+                                 detected) {
+                dev_dbg(&adap->dev, "Removing %s at 0x%x\n", client->name,
+                        client->addr);
+                list_del(&client->detected);
+                i2c_unregister_device(client);
         }
+        i2c_unlock_adapter(adap);
 
         /* Detach any active clients. This can't fail, thus we do not
            checking the returned value. */
@@ -1260,12 +1266,23 @@ static int i2c_detect_address(struct i2c_client *temp_client,
                 return 0;
 
         /* Make sure there is something at this address */
-        if (i2c_smbus_xfer(adapter, addr, 0, 0, 0, I2C_SMBUS_QUICK, NULL) < 0)
-                return 0;
+        if (addr == 0x73 && (adapter->class & I2C_CLASS_HWMON)) {
+                /* Special probe for FSC hwmon chips */
+                union i2c_smbus_data dummy;
 
-        /* Prevent 24RF08 corruption */
-        if ((addr & ~0x0f) == 0x50)
-                i2c_smbus_xfer(adapter, addr, 0, 0, 0, I2C_SMBUS_QUICK, NULL);
+                if (i2c_smbus_xfer(adapter, addr, 0, I2C_SMBUS_READ, 0,
+                                   I2C_SMBUS_BYTE_DATA, &dummy) < 0)
+                        return 0;
+        } else {
+                if (i2c_smbus_xfer(adapter, addr, 0, I2C_SMBUS_WRITE, 0,
+                                   I2C_SMBUS_QUICK, NULL) < 0)
+                        return 0;
+
+                /* Prevent 24RF08 corruption */
+                if ((addr & ~0x0f) == 0x50)
+                        i2c_smbus_xfer(adapter, addr, 0, I2C_SMBUS_WRITE, 0,
+                                       I2C_SMBUS_QUICK, NULL);
+        }
 
         /* Finally call the custom detection function */
         memset(&info, 0, sizeof(struct i2c_board_info));