[SCSI] qla2xxx: Allow the user the option of disabling iIDMA.

iIDMA support requires the driver issue several additional
fabric-managegment (FM) commands per port discovered during SNS
scanning -- GFPN (Get Fabric Port Name) and GPSC (Get Port Speed
Capabilities).  It has been found during testing that some
switches do not respond as *well* as expected to these commands
(silence -- no ACC nor BS_RJT).  So, to handle such conditions,
allow the user the ability to indirectly disable the FM commands
by disabling iIDMA with the ql2xiidmaenable module-parameter.

Signed-off-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c
index e98d502..9c3a57f 100644
--- a/drivers/scsi/qla2xxx/qla_os.c
+++ b/drivers/scsi/qla2xxx/qla_os.c
@@ -86,6 +86,13 @@
 		"depth for a device after a queue-full condition has been "
 		"detected.  Default is 120 seconds.");
 
+int ql2xiidmaenable=1;
+module_param(ql2xiidmaenable, int, S_IRUGO|S_IRUSR);
+MODULE_PARM_DESC(ql2xiidmaenable,
+		"Enables iIDMA settings "
+		"Default is 1 - perform iIDMA. 0 - no iIDMA.");
+
+
 /*
  * SCSI host template entry points
  */