===== drivers/scsi/scsi.c 1.50 vs edited =====
--- 1.50/drivers/scsi/scsi.c	Tue Oct 22 12:43:29 2002
+++ edited/drivers/scsi/scsi.c	Fri Oct 25 13:23:32 2002
@@ -1224,6 +1224,12 @@
 	SCSI_LOG_MLQUEUE(3, printk("Leaving scsi_do_cmd()\n"));
 }
 
+static void scsi_null_done_method(Scsi_Cmnd *SCp)
+{
+	printk(KERN_EMERG "Done called on already done command\n");
+        dump_stack();
+}
+
 /**
  * scsi_done - Mark this command as done
  * @SCpnt: The SCSI Command which we think we've completed.
@@ -1247,6 +1253,10 @@
 	unsigned long flags;
 	int cpu, tstatus;
 	struct softscsi_data *queue;
+
+        /* clear out the done method to produce an error for done on the
+         * same command */
+        SCpnt->scsi_done = scsi_null_done_method;
 
 	/*
 	 * We don't have to worry about this one timing out any more.