qla2xxx: Restore WWPN in case of Loop Dead.

For FA-WWPN capable device, ISP2031 and ISP27XX, when loop
dead is detected by a driver, restore WWPN from NVRAM.
Signed-off-by: Himanshu Madhani <himanshu.madhani@qlogic.com>
Signed-off-by: Saurav Kashyap <saurav.kashyap@qlogic.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/scsi/qla2xxx/qla_dbg.c

@@ -11,8 +11,7 @@
  * ----------------------------------------------------------------------
  * |             Level            |   Last Value Used  |     Holes	|
  * ----------------------------------------------------------------------
- * | Module Init and Probe        |       0x017d       | 0x0141		|
- * |                              |                    | 0x0144,0x0146	|
+ * | Module Init and Probe        |       0x017d       | 0x0144,0x0146	|
  * |                              |                    | 0x015b-0x0160	|
  * |                              |                    | 0x016e-0x0170	|
  * | Mailbox commands             |       0x118d       | 0x1115-0x1116	|

drivers/scsi/qla2xxx/qla_def.h

@@ -2945,7 +2945,8 @@ struct qla_hw_data {
 
 		uint32_t        mr_reset_hdlr_active:1;
 		uint32_t        mr_intr_valid:1;
-		/* 34 bits */
+		uint32_t	fawwpn_enabled:1;
+		/* 35 bits */
 	} flags;
 
 	/* This spinlock is used to protect "io transactions", you must

drivers/scsi/qla2xxx/qla_init.c

@@ -2202,6 +2202,11 @@ qla2x00_init_rings(scsi_qla_host_t *vha)
 		if (IS_DPORT_CAPABLE(ha))
 			mid_init_cb->init_cb.firmware_options_1 |=
 			    cpu_to_le16(BIT_7);
+		/* Enable FA-WWPN */
+		ha->flags.fawwpn_enabled =
+		    (mid_init_cb->init_cb.firmware_options_1 & BIT_6) ? 1 : 0;
+		ql_dbg(ql_dbg_init, vha, 0x0141, "FA-WWPN Support: %s.\n",
+		    (ha->flags.fawwpn_enabled) ? "enabled" : "disabled");
 	}
 
 	rval = qla2x00_init_firmware(vha, ha->init_cb_size);

drivers/scsi/qla2xxx/qla_isr.c

@@ -752,6 +752,16 @@ qla2x00_async_event(scsi_qla_host_t *vha, struct rsp_que *rsp, uint16_t *mb)
 		if (atomic_read(&vha->loop_state) != LOOP_DOWN) {
 			atomic_set(&vha->loop_state, LOOP_DOWN);
 			atomic_set(&vha->loop_down_timer, LOOP_DOWN_TIME);
+			/*
+			 * In case of loop down, restore WWPN from
+			 * NVRAM in case of FA-WWPN capable ISP
+			 */
+			if (ha->flags.fawwpn_enabled) {
+				void *wwpn = ha->init_cb->port_name;
+
+				memcpy(vha->port_name, wwpn, WWN_SIZE);
+			}
+
 			vha->device_flags |= DFLG_NO_CABLE;
 			qla2x00_mark_all_devices_lost(vha, 1);
 		}