ipmi:msghandler: Move timer handling into a work queue

Get all operations that manipulate the interface list into thread
context.

Signed-off-by: Corey Minyard <cminyard@mvista.com>

Author: cminyard

drivers/char/ipmi/ipmi_msghandler.c

@@ -5083,8 +5083,11 @@ static struct timer_list ipmi_timer;
 
 static atomic_t stop_operation;
 
-static void ipmi_timeout(struct timer_list *unused)
+static void ipmi_timeout_work(struct work_struct *work)
 {
+	if (atomic_read(&stop_operation))
+		return;
+
 	struct ipmi_smi *intf;
 	bool need_timer = false;
 	int index;
@@ -5111,6 +5114,16 @@ static void ipmi_timeout(struct timer_list *unused)
 		mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
 }
 
+static DECLARE_WORK(ipmi_timer_work, ipmi_timeout_work);
+
+static void ipmi_timeout(struct timer_list *unused)
+{
+	if (atomic_read(&stop_operation))
+		return;
+
+	queue_work(system_bh_wq, &ipmi_timer_work);
+}
+
 static void need_waiter(struct ipmi_smi *intf)
 {
 	/* Racy, but worst case we start the timer twice. */
@@ -5538,6 +5551,7 @@ static void __exit cleanup_ipmi(void)
 		 */
 		atomic_set(&stop_operation, 1);
 		timer_delete_sync(&ipmi_timer);
+		cancel_work_sync(&ipmi_timer_work);
 
 		initialized = false;