Added spinlock to mite_struct for mite_alloc_channel() and

mite_free_channel().

diff --git a/comedi/drivers/mite.c b/comedi/drivers/mite.c
index 81dd1449708da2537faba0ec986517a5ca63854d..076c8e57c0084688ce88a1aa6084f98c55f5a994 100644 (file)
--- a/comedi/drivers/mite.c
+++ b/comedi/drivers/mite.c
@@ -83,7 +83,7 @@ void mite_init(void)
                                return;
                        }
                        memset(mite,0,sizeof(*mite));
-
+                       spin_lock_init(&mite->lock);
                        mite->pcidev=pci_dev_get(pcidev);
 
                        mite->next=mite_devices;
@@ -224,24 +224,34 @@ void mite_list_devices(void)
 
 int mite_alloc_channel(struct mite_struct *mite)
 {
-       //FIXME spin lock so mite_free_channel can be called safely from interrupts
        int i;
+       unsigned long flags;
+       int retval = -1;
+
+       // spin lock so mite_free_channel can be called safely from interrupts
+       comedi_spin_lock_irqsave(&mite->lock, flags);
        for(i = 0; i < mite->num_channels; ++i)
        {
                if(mite->channel_allocated[i] == 0)
                {
                        mite->channel_allocated[i] = 1;
-                       return i;
+                       retval = i;
+                       break;
                }
        }
-       return -1;
+       comedi_spin_unlock_irqrestore(&mite->lock, flags);
+       return retval;
 }
 
 void mite_free_channel(struct mite_struct *mite, unsigned channel)
 {
-       //FIXME spin lock to prevent races with mite_alloc_channel
+       unsigned long flags;
+
        BUG_ON(channel >= mite->num_channels);
+       // spin lock to prevent races with mite_alloc_channel
+       comedi_spin_lock_irqsave(&mite->lock, flags);
        mite->channel_allocated[channel] = 0;
+       comedi_spin_unlock_irqrestore(&mite->lock, flags);
 }
 
 void mite_dma_arm( struct mite_struct *mite, unsigned int channel )

diff --git a/comedi/drivers/mite.h b/comedi/drivers/mite.h
index 50dd58c4813240fc3e526843347834fce6264cd0..387376b1925ca83f1395726f8a673f2d0a068c1e 100644 (file)
--- a/comedi/drivers/mite.h
+++ b/comedi/drivers/mite.h
@@ -71,6 +71,7 @@ struct mite_struct{
        struct mite_channel channels[MAX_MITE_DMA_CHANNELS];
        short channel_allocated[MAX_MITE_DMA_CHANNELS];
        int num_channels;
+       spinlock_t lock;
 };
 
 extern struct mite_struct *mite_devices;