[SCSI] hpsa: allow driver to put controller in either simple or performant mode

Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c
index 4fb62c2..10076f1 100644
--- a/drivers/scsi/hpsa.c
+++ b/drivers/scsi/hpsa.c
@@ -74,6 +74,10 @@
 module_param(hpsa_allow_any, int, S_IRUGO|S_IWUSR);
 MODULE_PARM_DESC(hpsa_allow_any,
 		"Allow hpsa driver to access unknown HP Smart Array hardware");
+static int hpsa_simple_mode;
+module_param(hpsa_simple_mode, int, S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(hpsa_simple_mode,
+	"Use 'simple mode' rather than 'performant mode'");
 
 /* define the PCI info for the cards we can control */
 static const struct pci_device_id hpsa_pci_device_id[] = {
@@ -4038,6 +4042,9 @@
 {
 	u32 trans_support;
 
+	if (hpsa_simple_mode)
+		return;
+
 	trans_support = readl(&(h->cfgtable->TransportSupport));
 	if (!(trans_support & PERFORMANT_MODE))
 		return;