1 files changed, 40 insertions, 4 deletions

diff --git a/sound/core/timer.c b/sound/core/timer.c
index af1f68f7e315..9b513a05765a 100644
--- a/sound/core/timer.c
+++ b/sound/core/timer.c
@@ -451,6 +451,10 @@ static int snd_timer_start_slave(struct snd_timer_instance *timeri)
         unsigned long flags;
 
         spin_lock_irqsave(&slave_active_lock, flags);
+        if (timeri->flags & SNDRV_TIMER_IFLG_RUNNING) {
+                spin_unlock_irqrestore(&slave_active_lock, flags);
+                return -EBUSY;
+        }
         timeri->flags |= SNDRV_TIMER_IFLG_RUNNING;
         if (timeri->master && timeri->timer) {
                 spin_lock(&timeri->timer->lock);
@@ -475,7 +479,8 @@ int snd_timer_start(struct snd_timer_instance *timeri, unsigned int ticks)
                 return -EINVAL;
         if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
                 result = snd_timer_start_slave(timeri);
-                snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_START);
+                if (result >= 0)
+                        snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_START);
                 return result;
         }
         timer = timeri->timer;
@@ -484,11 +489,18 @@ int snd_timer_start(struct snd_timer_instance *timeri, unsigned int ticks)
         if (timer->card && timer->card->shutdown)
                 return -ENODEV;
         spin_lock_irqsave(&timer->lock, flags);
+        if (timeri->flags & (SNDRV_TIMER_IFLG_RUNNING |
+                             SNDRV_TIMER_IFLG_START)) {
+                result = -EBUSY;
+                goto unlock;
+        }
         timeri->ticks = timeri->cticks = ticks;
         timeri->pticks = 0;
         result = snd_timer_start1(timer, timeri, ticks);
+ unlock:
         spin_unlock_irqrestore(&timer->lock, flags);
-        snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_START);
+        if (result >= 0)
+                snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_START);
         return result;
 }
 
@@ -502,6 +514,10 @@ static int _snd_timer_stop(struct snd_timer_instance *timeri, int event)
 
         if (timeri->flags & SNDRV_TIMER_IFLG_SLAVE) {
                 spin_lock_irqsave(&slave_active_lock, flags);
+                if (!(timeri->flags & SNDRV_TIMER_IFLG_RUNNING)) {
+                        spin_unlock_irqrestore(&slave_active_lock, flags);
+                        return -EBUSY;
+                }
                 timeri->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
                 list_del_init(&timeri->ack_list);
                 list_del_init(&timeri->active_list);
@@ -512,6 +528,11 @@ static int _snd_timer_stop(struct snd_timer_instance *timeri, int event)
         if (!timer)
                 return -EINVAL;
         spin_lock_irqsave(&timer->lock, flags);
+        if (!(timeri->flags & (SNDRV_TIMER_IFLG_RUNNING |
+                               SNDRV_TIMER_IFLG_START))) {
+                spin_unlock_irqrestore(&timer->lock, flags);
+                return -EBUSY;
+        }
         list_del_init(&timeri->ack_list);
         list_del_init(&timeri->active_list);
         if (timer->card && timer->card->shutdown) {
@@ -581,10 +602,15 @@ int snd_timer_continue(struct snd_timer_instance *timeri)
         if (timer->card && timer->card->shutdown)
                 return -ENODEV;
         spin_lock_irqsave(&timer->lock, flags);
+        if (timeri->flags & SNDRV_TIMER_IFLG_RUNNING) {
+                result = -EBUSY;
+                goto unlock;
+        }
         if (!timeri->cticks)
                 timeri->cticks = 1;
         timeri->pticks = 0;
         result = snd_timer_start1(timer, timeri, timer->sticks);
+ unlock:
         spin_unlock_irqrestore(&timer->lock, flags);
         snd_timer_notify1(timeri, SNDRV_TIMER_EVENT_CONTINUE);
         return result;
@@ -718,8 +744,8 @@ void snd_timer_interrupt(struct snd_timer * timer, unsigned long ticks_left)
                         ti->cticks = ti->ticks;
                 } else {
                         ti->flags &= ~SNDRV_TIMER_IFLG_RUNNING;
-                        if (--timer->running)
-                                list_del_init(&ti->active_list);
+                        --timer->running;
+                        list_del_init(&ti->active_list);
                 }
                 if ((timer->hw.flags & SNDRV_TIMER_HW_TASKLET) ||
                     (ti->flags & SNDRV_TIMER_IFLG_FAST))
@@ -1032,11 +1058,21 @@ static int snd_timer_s_stop(struct snd_timer * timer)
         return 0;
 }
 
+static int snd_timer_s_close(struct snd_timer *timer)
+{
+        struct snd_timer_system_private *priv;
+
+        priv = (struct snd_timer_system_private *)timer->private_data;
+        del_timer_sync(&priv->tlist);
+        return 0;
+}
+
 static struct snd_timer_hardware snd_timer_system =
 {
         .flags =        SNDRV_TIMER_HW_FIRST | SNDRV_TIMER_HW_TASKLET,
         .resolution =   1000000000L / HZ,
         .ticks =        10000000L,
+        .close =        snd_timer_s_close,
         .start =        snd_timer_s_start,
         .stop =         snd_timer_s_stop
 };