Fix problem detecting DMA overflows at buffer wraparound

diff --git a/comedi/drivers/ni_mio_common.c b/comedi/drivers/ni_mio_common.c
index a97c63cd60402c25825738d0f141a7144f90dafd..daf501b9abf7ea87a8ec74850240fc15d0d9390d 100644 (file)
--- a/comedi/drivers/ni_mio_common.c
+++ b/comedi/drivers/ni_mio_common.c
@@ -355,7 +355,7 @@ static void mite_handle_a_linkc(struct mite_struct *mite, comedi_device *dev)
        writel(CHOR_CLRLC, mite->mite_io_addr+MITE_CHOR+CHAN_OFFSET(mite->chan));
 
        nbytes = mite_bytes_transferred(mite, 0);
-       if(nbytes >= async->buf_free_count){
+       if((int)(nbytes - async->buf_free_count) >= 0){
                printk("ni_mio_common: BUG: DMA overwrite of free area\n");
                ni_ai_reset(dev,s);
                async->events |= COMEDI_CB_OVERFLOW;