added a memory barrier to try and fix mysterious 6402/16 crash

on attach

diff --git a/comedi/drivers/cb_pcidas64.c b/comedi/drivers/cb_pcidas64.c
index 5077bd4d1ceae88a6d57461b38a728bab1abe269..c1c752d67481496b516397e8cf191857a9e6a451 100644 (file)
--- a/comedi/drivers/cb_pcidas64.c
+++ b/comedi/drivers/cb_pcidas64.c
@@ -86,6 +86,7 @@ TODO:
 #include <linux/comedidev.h>
 #include <linux/delay.h>
 #include <linux/pci.h>
+#include <asm/system.h>
 
 #include "8253.h"
 #include "8255.h"
@@ -1700,15 +1701,16 @@ static int attach(comedi_device *dev, comedi_devconfig *it)
        if(retval < 0) return retval;
 
        priv(dev)->hw_revision = hw_revision( dev, readw(priv(dev)->main_iobase + HW_STATUS_REG ) );
-
        printk(" stc hardware revision %i\n", priv(dev)->hw_revision);
-
        retval = setup_subdevices(dev);
        if(retval < 0)
        {
                return retval;
        }
-
+       /* make sure everything is written out to memory before there is a possibility
+        * of the interrupt handler executing (trying to fix mysterious pci-das6402/16
+        * crash during attach) */
+       mb();
        // get irq
        if(comedi_request_irq(pcidev->irq, handle_interrupt, SA_SHIRQ, "cb_pcidas64", dev ))
        {