fix race in setting COMEDI_CB_EOS event with dma

diff --git a/comedi/drivers/ni_mio_common.c b/comedi/drivers/ni_mio_common.c
index be7ee23ed8cbec6e32ce9a70a407ae55a5bd4acb..748eb6fc957697329ceb76a40c2c67ef96aa4f84 100644 (file)
--- a/comedi/drivers/ni_mio_common.c
+++ b/comedi/drivers/ni_mio_common.c
@@ -336,6 +336,7 @@ static void mite_handle_a_linkc(struct mite_struct *mite, comedi_device *dev)
        comedi_subdevice *s = dev->subdevices + 0;
        comedi_async *async = s->async;
        unsigned int nbytes, old_alloc_count;
+       unsigned int bytes_per_scan = 2 * async->cmd.chanlist_len;
 
        writel(CHOR_CLRLC, mite->mite_io_addr + MITE_CHOR + CHAN_OFFSET(AI_DMA_CHAN));
 
@@ -360,6 +361,12 @@ static void mite_handle_a_linkc(struct mite_struct *mite, comedi_device *dev)
        comedi_buf_munge(dev, s, count);
        comedi_buf_write_free(async, count);
 
+       async->scan_progress += count;
+       if( async->scan_progress >= bytes_per_scan )
+       {
+               async->scan_progress %= bytes_per_scan;
+               async->events |= COMEDI_CB_EOS;
+       }
        async->events |= COMEDI_CB_BLOCK;
 }
 
@@ -584,8 +591,8 @@ static void handle_a_interrupt(comedi_device *dev,unsigned short status,
                mite_handle_a_linkc(devpriv->mite, dev);
 #else
                ni_handle_fifo_dregs(dev);
-#endif
                s->async->events |= COMEDI_CB_EOS;
+#endif
 
                /* we need to ack the START, also */
                ack|=AI_STOP_Interrupt_Ack|AI_START_Interrupt_Ack;