igb: Fix for lockdep issue in igb_get_i2c_client

This patch fixes a lockdep warning in igb_get_i2c_client by
refactoring the initialization and usage of the i2c_client
completely.  There is no on the fly allocation of the single
client needed today.

Signed-off-by: Carolyn Wyborny <carolyn.wyborny@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

3 files changed, 17 insertions, 68 deletions

diff --git a/drivers/net/ethernet/intel/igb/igb.h b/drivers/net/ethernet/intel/igb/igb.h
index d27edbc63923..25151401c2ab 100644
--- a/drivers/net/ethernet/intel/igb/igb.h
+++ b/drivers/net/ethernet/intel/igb/igb.h
@@ -447,7 +447,7 @@ struct igb_adapter {
 #endif
         struct i2c_algo_bit_data i2c_algo;
         struct i2c_adapter i2c_adap;
-        struct igb_i2c_client_list *i2c_clients;
+        struct i2c_client *i2c_client;
 };
 
 #define IGB_FLAG_HAS_MSI                (1 << 0)
diff --git a/drivers/net/ethernet/intel/igb/igb_hwmon.c b/drivers/net/ethernet/intel/igb/igb_hwmon.c
index 0a9b073d0b03..4623502054d5 100644
--- a/drivers/net/ethernet/intel/igb/igb_hwmon.c
+++ b/drivers/net/ethernet/intel/igb/igb_hwmon.c
@@ -39,6 +39,10 @@
 #include <linux/pci.h>
 
 #ifdef CONFIG_IGB_HWMON
+struct i2c_board_info i350_sensor_info = {
+        I2C_BOARD_INFO("i350bb", (0Xf8 >> 1)),
+};
+
 /* hwmon callback functions */
 static ssize_t igb_hwmon_show_location(struct device *dev,
                                          struct device_attribute *attr,
@@ -188,6 +192,7 @@ int igb_sysfs_init(struct igb_adapter *adapter)
         unsigned int i;
         int n_attrs;
         int rc = 0;
+        struct i2c_client *client = NULL;
 
         /* If this method isn't defined we don't support thermals */
         if (adapter->hw.mac.ops.init_thermal_sensor_thresh == NULL)
@@ -198,6 +203,15 @@ int igb_sysfs_init(struct igb_adapter *adapter)
                 if (rc)
                         goto exit;
 
+        /* init i2c_client */
+        client = i2c_new_device(&adapter->i2c_adap, &i350_sensor_info);
+        if (client == NULL) {
+                dev_info(&adapter->pdev->dev,
+                        "Failed to create new i2c device..\n");
+                goto exit;
+        }
+        adapter->i2c_client = client;
+
         /* Allocation space for max attributes
          * max num sensors * values (loc, temp, max, caution)
          */
diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
index 4d53a17959fa..4dbd62968c7a 100644
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -1923,10 +1923,6 @@ void igb_set_fw_version(struct igb_adapter *adapter)
         return;
 }
 
-static const struct i2c_board_info i350_sensor_info = {
-        I2C_BOARD_INFO("i350bb", 0Xf8),
-};
-
 /*  igb_init_i2c - Init I2C interface
  *  @adapter: pointer to adapter structure
  *
@@ -7717,67 +7713,6 @@ static void igb_init_dmac(struct igb_adapter *adapter, u32 pba)
         }
 }
 
-static DEFINE_SPINLOCK(i2c_clients_lock);
-
-/*  igb_get_i2c_client - returns matching client
- *  in adapters's client list.
- *  @adapter: adapter struct
- *  @dev_addr: device address of i2c needed.
- */
-static struct i2c_client *
-igb_get_i2c_client(struct igb_adapter *adapter, u8 dev_addr)
-{
-        ulong flags;
-        struct igb_i2c_client_list *client_list;
-        struct i2c_client *client = NULL;
-        struct i2c_board_info client_info = {
-                I2C_BOARD_INFO("igb", 0x00),
-        };
-
-        spin_lock_irqsave(&i2c_clients_lock, flags);
-        client_list = adapter->i2c_clients;
-
-        /* See if we already have an i2c_client */
-        while (client_list) {
-                if (client_list->client->addr == (dev_addr >> 1)) {
-                        client = client_list->client;
-                        goto exit;
-                } else {
-                        client_list = client_list->next;
-                }
-        }
-
-        /* no client_list found, create a new one */
-        client_list = kzalloc(sizeof(*client_list), GFP_ATOMIC);
-        if (client_list == NULL)
-                goto exit;
-
-        /* dev_addr passed to us is left-shifted by 1 bit
-         * i2c_new_device call expects it to be flush to the right.
-         */
-        client_info.addr = dev_addr >> 1;
-        client_info.platform_data = adapter;
-        client_list->client = i2c_new_device(&adapter->i2c_adap, &client_info);
-        if (client_list->client == NULL) {
-                dev_info(&adapter->pdev->dev,
-                        "Failed to create new i2c device..\n");
-                goto err_no_client;
-        }
-
-        /* insert new client at head of list */
-        client_list->next = adapter->i2c_clients;
-        adapter->i2c_clients = client_list;
-
-        client = client_list->client;
-        goto exit;
-
-err_no_client:
-        kfree(client_list);
-exit:
-        spin_unlock_irqrestore(&i2c_clients_lock, flags);
-        return client;
-}
-
 /*  igb_read_i2c_byte - Reads 8 bit word over I2C
  *  @hw: pointer to hardware structure
  *  @byte_offset: byte offset to read
@@ -7791,7 +7726,7 @@ s32 igb_read_i2c_byte(struct e1000_hw *hw, u8 byte_offset,
                                 u8 dev_addr, u8 *data)
 {
         struct igb_adapter *adapter = container_of(hw, struct igb_adapter, hw);
-        struct i2c_client *this_client = igb_get_i2c_client(adapter, dev_addr);
+        struct i2c_client *this_client = adapter->i2c_client;
         s32 status;
         u16 swfw_mask = 0;
 
@@ -7828,7 +7763,7 @@ s32 igb_write_i2c_byte(struct e1000_hw *hw, u8 byte_offset,
                                  u8 dev_addr, u8 data)
 {
         struct igb_adapter *adapter = container_of(hw, struct igb_adapter, hw);
-        struct i2c_client *this_client = igb_get_i2c_client(adapter, dev_addr);
+        struct i2c_client *this_client = adapter->i2c_client;
         s32 status;
         u16 swfw_mask = E1000_SWFW_PHY0_SM;