static int ipmi_init_msghandler(void);
 static void smi_recv_tasklet(unsigned long);
 static void handle_new_recv_msgs(ipmi_smi_t intf);
+static void need_waiter(ipmi_smi_t intf);
 
 static int initialized;
 
  */
 #define MAX_MSG_TIMEOUT                60000
 
+/* Call every ~1000 ms. */
+#define IPMI_TIMEOUT_TIME      1000
+
+/* How many jiffies does it take to get to the timeout time. */
+#define IPMI_TIMEOUT_JIFFIES   ((IPMI_TIMEOUT_TIME * HZ) / 1000)
+
+/*
+ * Request events from the queue every second (this is the number of
+ * IPMI_TIMEOUT_TIMES between event requests).  Hopefully, in the
+ * future, IPMI will add a way to know immediately if an event is in
+ * the queue and this silliness can go away.
+ */
+#define IPMI_REQUEST_EV_TIME   (1000 / (IPMI_TIMEOUT_TIME))
+
 /*
  * The main "user" data structure.
  */
        ipmi_smi_t intf;
 
        /* Does this interface receive IPMI events? */
-       int gets_events;
+       bool gets_events;
 };
 
 struct cmd_rcvr {
        unsigned int     waiting_events_count; /* How many events in queue? */
        char             delivering_events;
        char             event_msg_printed;
+       atomic_t         event_waiters;
+       unsigned int     ticks_to_req_ev;
+       int              last_needs_timer;
 
        /*
         * The event receiver for my BMC, only really used at panic
 static LIST_HEAD(smi_watchers);
 static DEFINE_MUTEX(smi_watchers_mutex);
 
-
 #define ipmi_inc_stat(intf, stat) \
        atomic_inc(&(intf)->stats[IPMI_STAT_ ## stat])
 #define ipmi_get_stat(intf, stat) \
                *seq = i;
                *seqid = intf->seq_table[i].seqid;
                intf->curr_seq = (i+1)%IPMI_IPMB_NUM_SEQ;
+               need_waiter(intf);
        } else {
                rv = -EAGAIN;
        }
        new_user->handler = handler;
        new_user->handler_data = handler_data;
        new_user->intf = intf;
-       new_user->gets_events = 0;
+       new_user->gets_events = false;
 
        if (!try_module_get(intf->handlers->owner)) {
                rv = -ENODEV;
        spin_lock_irqsave(&intf->seq_lock, flags);
        list_add_rcu(&new_user->link, &intf->users);
        spin_unlock_irqrestore(&intf->seq_lock, flags);
+       if (handler->ipmi_watchdog_pretimeout) {
+               /* User wants pretimeouts, so make sure to watch for them. */
+               if (atomic_inc_return(&intf->event_waiters) == 1)
+                       need_waiter(intf);
+       }
        *user = new_user;
        return 0;
 
 
        user->valid = 0;
 
+       if (user->handler->ipmi_watchdog_pretimeout)
+               atomic_dec(&intf->event_waiters);
+
+       if (user->gets_events)
+               atomic_dec(&intf->event_waiters);
+
        /* Remove the user from the interface's sequence table. */
        spin_lock_irqsave(&intf->seq_lock, flags);
        list_del_rcu(&user->link);
 }
 EXPORT_SYMBOL(ipmi_set_maintenance_mode);
 
-int ipmi_set_gets_events(ipmi_user_t user, int val)
+int ipmi_set_gets_events(ipmi_user_t user, bool val)
 {
        unsigned long        flags;
        ipmi_smi_t           intf = user->intf;
        INIT_LIST_HEAD(&msgs);
 
        spin_lock_irqsave(&intf->events_lock, flags);
+       if (user->gets_events == val)
+               goto out;
+
        user->gets_events = val;
 
+       if (val) {
+               if (atomic_inc_return(&intf->event_waiters) == 1)
+                       need_waiter(intf);
+       } else {
+               atomic_dec(&intf->event_waiters);
+       }
+
        if (intf->delivering_events)
                /*
                 * Another thread is delivering events for this, so
                goto out_unlock;
        }
 
+       if (atomic_inc_return(&intf->event_waiters) == 1)
+               need_waiter(intf);
+
        list_add_rcu(&rcvr->link, &intf->cmd_rcvrs);
 
  out_unlock:
        mutex_unlock(&intf->cmd_rcvrs_mutex);
        synchronize_rcu();
        while (rcvrs) {
+               atomic_dec(&intf->event_waiters);
                rcvr = rcvrs;
                rcvrs = rcvr->next;
                kfree(rcvr);
                     (unsigned long) intf);
        atomic_set(&intf->watchdog_pretimeouts_to_deliver, 0);
        spin_lock_init(&intf->events_lock);
+       atomic_set(&intf->event_waiters, 0);
+       intf->ticks_to_req_ev = IPMI_REQUEST_EV_TIME;
        INIT_LIST_HEAD(&intf->waiting_events);
        intf->waiting_events_count = 0;
        mutex_init(&intf->cmd_rcvrs_mutex);
 
 static void check_msg_timeout(ipmi_smi_t intf, struct seq_table *ent,
                              struct list_head *timeouts, long timeout_period,
-                             int slot, unsigned long *flags)
+                             int slot, unsigned long *flags,
+                             unsigned int *waiting_msgs)
 {
        struct ipmi_recv_msg     *msg;
        struct ipmi_smi_handlers *handlers;
                return;
 
        ent->timeout -= timeout_period;
-       if (ent->timeout > 0)
+       if (ent->timeout > 0) {
+               (*waiting_msgs)++;
                return;
+       }
 
        if (ent->retries_left == 0) {
                /* The message has used all its retries. */
                struct ipmi_smi_msg *smi_msg;
                /* More retries, send again. */
 
+               (*waiting_msgs)++;
+
                /*
                 * Start with the max timer, set to normal timer after
                 * the message is sent.
        }
 }
 
-static void ipmi_timeout_handler(long timeout_period)
+static unsigned int ipmi_timeout_handler(ipmi_smi_t intf, long timeout_period)
 {
-       ipmi_smi_t           intf;
        struct list_head     timeouts;
        struct ipmi_recv_msg *msg, *msg2;
        unsigned long        flags;
        int                  i;
+       unsigned int         waiting_msgs = 0;
 
-       rcu_read_lock();
-       list_for_each_entry_rcu(intf, &ipmi_interfaces, link) {
-               tasklet_schedule(&intf->recv_tasklet);
-
-               /*
-                * Go through the seq table and find any messages that
-                * have timed out, putting them in the timeouts
-                * list.
-                */
-               INIT_LIST_HEAD(&timeouts);
-               spin_lock_irqsave(&intf->seq_lock, flags);
-               for (i = 0; i < IPMI_IPMB_NUM_SEQ; i++)
-                       check_msg_timeout(intf, &(intf->seq_table[i]),
-                                         &timeouts, timeout_period, i,
-                                         &flags);
-               spin_unlock_irqrestore(&intf->seq_lock, flags);
+       /*
+        * Go through the seq table and find any messages that
+        * have timed out, putting them in the timeouts
+        * list.
+        */
+       INIT_LIST_HEAD(&timeouts);
+       spin_lock_irqsave(&intf->seq_lock, flags);
+       for (i = 0; i < IPMI_IPMB_NUM_SEQ; i++)
+               check_msg_timeout(intf, &(intf->seq_table[i]),
+                                 &timeouts, timeout_period, i,
+                                 &flags, &waiting_msgs);
+       spin_unlock_irqrestore(&intf->seq_lock, flags);
 
-               list_for_each_entry_safe(msg, msg2, &timeouts, link)
-                       deliver_err_response(msg, IPMI_TIMEOUT_COMPLETION_CODE);
+       list_for_each_entry_safe(msg, msg2, &timeouts, link)
+               deliver_err_response(msg, IPMI_TIMEOUT_COMPLETION_CODE);
 
-               /*
-                * Maintenance mode handling.  Check the timeout
-                * optimistically before we claim the lock.  It may
-                * mean a timeout gets missed occasionally, but that
-                * only means the timeout gets extended by one period
-                * in that case.  No big deal, and it avoids the lock
-                * most of the time.
-                */
+       /*
+        * Maintenance mode handling.  Check the timeout
+        * optimistically before we claim the lock.  It may
+        * mean a timeout gets missed occasionally, but that
+        * only means the timeout gets extended by one period
+        * in that case.  No big deal, and it avoids the lock
+        * most of the time.
+        */
+       if (intf->auto_maintenance_timeout > 0) {
+               spin_lock_irqsave(&intf->maintenance_mode_lock, flags);
                if (intf->auto_maintenance_timeout > 0) {
-                       spin_lock_irqsave(&intf->maintenance_mode_lock, flags);
-                       if (intf->auto_maintenance_timeout > 0) {
-                               intf->auto_maintenance_timeout
-                                       -= timeout_period;
-                               if (!intf->maintenance_mode
-                                   && (intf->auto_maintenance_timeout <= 0)) {
-                                       intf->maintenance_mode_enable = 0;
-                                       maintenance_mode_update(intf);
-                               }
+                       intf->auto_maintenance_timeout
+                               -= timeout_period;
+                       if (!intf->maintenance_mode
+                           && (intf->auto_maintenance_timeout <= 0)) {
+                               intf->maintenance_mode_enable = 0;
+                               maintenance_mode_update(intf);
                        }
-                       spin_unlock_irqrestore(&intf->maintenance_mode_lock,
-                                              flags);
                }
+               spin_unlock_irqrestore(&intf->maintenance_mode_lock,
+                                      flags);
        }
-       rcu_read_unlock();
+
+       tasklet_schedule(&intf->recv_tasklet);
+
+       return waiting_msgs;
 }
 
-static void ipmi_request_event(void)
+static void ipmi_request_event(ipmi_smi_t intf)
 {
-       ipmi_smi_t               intf;
        struct ipmi_smi_handlers *handlers;
 
-       rcu_read_lock();
-       /*
-        * Called from the timer, no need to check if handlers is
-        * valid.
-        */
-       list_for_each_entry_rcu(intf, &ipmi_interfaces, link) {
-               /* No event requests when in maintenance mode. */
-               if (intf->maintenance_mode_enable)
-                       continue;
+       /* No event requests when in maintenance mode. */
+       if (intf->maintenance_mode_enable)
+               return;
 
-               handlers = intf->handlers;
-               if (handlers)
-                       handlers->request_events(intf->send_info);
-       }
-       rcu_read_unlock();
+       handlers = intf->handlers;
+       if (handlers)
+               handlers->request_events(intf->send_info);
 }
 
 static struct timer_list ipmi_timer;
 
-/* Call every ~1000 ms. */
-#define IPMI_TIMEOUT_TIME      1000
-
-/* How many jiffies does it take to get to the timeout time. */
-#define IPMI_TIMEOUT_JIFFIES   ((IPMI_TIMEOUT_TIME * HZ) / 1000)
-
-/*
- * Request events from the queue every second (this is the number of
- * IPMI_TIMEOUT_TIMES between event requests).  Hopefully, in the
- * future, IPMI will add a way to know immediately if an event is in
- * the queue and this silliness can go away.
- */
-#define IPMI_REQUEST_EV_TIME   (1000 / (IPMI_TIMEOUT_TIME))
-
 static atomic_t stop_operation;
-static unsigned int ticks_to_req_ev = IPMI_REQUEST_EV_TIME;
 
 static void ipmi_timeout(unsigned long data)
 {
+       ipmi_smi_t intf;
+       int nt = 0;
+
        if (atomic_read(&stop_operation))
                return;
 
-       ticks_to_req_ev--;
-       if (ticks_to_req_ev == 0) {
-               ipmi_request_event();
-               ticks_to_req_ev = IPMI_REQUEST_EV_TIME;
-       }
+       rcu_read_lock();
+       list_for_each_entry_rcu(intf, &ipmi_interfaces, link) {
+               int lnt = 0;
+
+               if (atomic_read(&intf->event_waiters)) {
+                       intf->ticks_to_req_ev--;
+                       if (intf->ticks_to_req_ev == 0) {
+                               ipmi_request_event(intf);
+                               intf->ticks_to_req_ev = IPMI_REQUEST_EV_TIME;
+                       }
+                       lnt++;
+               }
 
-       ipmi_timeout_handler(IPMI_TIMEOUT_TIME);
+               lnt += ipmi_timeout_handler(intf, IPMI_TIMEOUT_TIME);
 
-       mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
+               lnt = !!lnt;
+               if (lnt != intf->last_needs_timer &&
+                                       intf->handlers->set_need_watch)
+                       intf->handlers->set_need_watch(intf->send_info, lnt);
+               intf->last_needs_timer = lnt;
+
+               nt += lnt;
+       }
+       rcu_read_unlock();
+
+       if (nt)
+               mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
 }
 
+static void need_waiter(ipmi_smi_t intf)
+{
+       /* Racy, but worst case we start the timer twice. */
+       if (!timer_pending(&ipmi_timer))
+               mod_timer(&ipmi_timer, jiffies + IPMI_TIMEOUT_JIFFIES);
+}
 
 static atomic_t smi_msg_inuse_count = ATOMIC_INIT(0);
 static atomic_t recv_msg_inuse_count = ATOMIC_INIT(0);
 
        /* Used to gracefully stop the timer without race conditions. */
        atomic_t            stop_operation;
 
+       /* Are we waiting for the events, pretimeouts, received msgs? */
+       atomic_t            need_watch;
+
        /*
         * The driver will disable interrupts when it gets into a
         * situation where it cannot handle messages due to lack of
        return si_sm_result;
 }
 
+static void check_start_timer_thread(struct smi_info *smi_info)
+{
+       if (smi_info->si_state == SI_NORMAL && smi_info->curr_msg == NULL) {
+               smi_mod_timer(smi_info, jiffies + SI_TIMEOUT_JIFFIES);
+
+               if (smi_info->thread)
+                       wake_up_process(smi_info->thread);
+
+               start_next_msg(smi_info);
+               smi_event_handler(smi_info, 0);
+       }
+}
+
 static void sender(void                *send_info,
                   struct ipmi_smi_msg *msg,
                   int                 priority)
        else
                list_add_tail(&msg->link, &smi_info->xmit_msgs);
 
-       if (smi_info->si_state == SI_NORMAL && smi_info->curr_msg == NULL) {
-               smi_mod_timer(smi_info, jiffies + SI_TIMEOUT_JIFFIES);
-
-               if (smi_info->thread)
-                       wake_up_process(smi_info->thread);
-
-               start_next_msg(smi_info);
-               smi_event_handler(smi_info, 0);
-       }
+       check_start_timer_thread(smi_info);
        spin_unlock_irqrestore(&smi_info->si_lock, flags);
 }
 
                        ; /* do nothing */
                else if (smi_result == SI_SM_CALL_WITH_DELAY && busy_wait)
                        schedule();
-               else if (smi_result == SI_SM_IDLE)
-                       schedule_timeout_interruptible(100);
-               else
+               else if (smi_result == SI_SM_IDLE) {
+                       if (atomic_read(&smi_info->need_watch)) {
+                               schedule_timeout_interruptible(100);
+                       } else {
+                               /* Wait to be woken up when we are needed. */
+                               __set_current_state(TASK_INTERRUPTIBLE);
+                               schedule();
+                       }
+               } else
                        schedule_timeout_interruptible(1);
        }
        return 0;
        atomic_set(&smi_info->req_events, 1);
 }
 
+static void set_need_watch(void *send_info, int enable)
+{
+       struct smi_info *smi_info = send_info;
+       unsigned long flags;
+
+       atomic_set(&smi_info->need_watch, enable);
+       spin_lock_irqsave(&smi_info->si_lock, flags);
+       check_start_timer_thread(smi_info);
+       spin_unlock_irqrestore(&smi_info->si_lock, flags);
+}
+
 static int initialized;
 
 static void smi_timeout(unsigned long data)
        .get_smi_info           = get_smi_info,
        .sender                 = sender,
        .request_events         = request_events,
+       .set_need_watch         = set_need_watch,
        .set_maintenance_mode   = set_maintenance_mode,
        .set_run_to_completion  = set_run_to_completion,
        .poll                   = poll,
 
        new_smi->interrupt_disabled = 1;
        atomic_set(&new_smi->stop_operation, 0);
+       atomic_set(&new_smi->need_watch, 0);
        new_smi->intf_num = smi_num;
        smi_num++;