firewire: use atomic type for fw_device.state

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

drivers/firewire/fw-card.c

@@ -302,7 +302,7 @@ fw_card_bm_work(struct work_struct *work)
 		/* Either link_on is false, or we failed to read the
 		 * config rom.  In either case, pick another root. */
 		new_root_id = card->local_node->node_id;
-	} else if (root->state != FW_DEVICE_RUNNING) {
+	} else if (atomic_read(&root->state) != FW_DEVICE_RUNNING) {
 		/* If we haven't probed this device yet, bail out now
 		 * and let's try again once that's done. */
 		spin_unlock_irqrestore(&card->lock, flags);

drivers/firewire/fw-device.c

@@ -494,7 +494,7 @@ static void fw_device_init(struct work_struct *work)
 	 * necessary.  We have to use the atomic cmpxchg here to avoid
 	 * racing with the FW_NODE_DESTROYED case in
 	 * fw_node_event(). */
-	if (cmpxchg(&device->state,
+	if (atomic_cmpxchg(&device->state,
 		    FW_DEVICE_INITIALIZING,
 		    FW_DEVICE_RUNNING) == FW_DEVICE_SHUTDOWN)
 		fw_device_shutdown(&device->work.work);
@@ -551,7 +551,7 @@ void fw_node_event(struct fw_card *card, struct fw_node *node, int event)
 		 * device_for_each_child() in FW_NODE_UPDATED is
 		 * doesn't freak out. */
 		device_initialize(&device->device);
-		device->state = FW_DEVICE_INITIALIZING;
+		atomic_set(&device->state, FW_DEVICE_INITIALIZING);
 		device->card = fw_card_get(card);
 		device->node = fw_node_get(node);
 		device->node_id = node->node_id;
@@ -596,7 +596,7 @@ void fw_node_event(struct fw_card *card, struct fw_node *node, int event)
 		 * the device in shutdown state to have that code fail
 		 * to create the device. */
 		device = node->data;
-		if (xchg(&device->state,
+		if (atomic_xchg(&device->state,
 			 FW_DEVICE_SHUTDOWN) == FW_DEVICE_RUNNING) {
 			INIT_DELAYED_WORK(&device->work, fw_device_shutdown);
 			schedule_delayed_work(&device->work, 0);

drivers/firewire/fw-device.h

@@ -24,6 +24,7 @@
 
 #include <linux/fs.h>
 #include <linux/cdev.h>
+#include <asm/atomic.h>
 
 enum fw_device_state {
 	FW_DEVICE_INITIALIZING,
@@ -32,7 +33,7 @@ enum fw_device_state {
 };
 
 struct fw_device {
-	int state;
+	atomic_t state;
 	struct fw_node *node;
 	int node_id;
 	int generation;