[SCSI] fcoe: Use NETIF_F_FCOE_MTU flag to set up max frame size (lport->mfs)
Add a define of FCOE_MTU as 2158 bytes and use FCOE_MTU when the LLD is found
to support NETIF_F_FCOE_MTU. The lport->mfs is then calculated out of the
2158 FCOE_MTU. Otherwise, we stick with the netdev->mtu, i.e., LAN MTU. Also,
change the notification on NETDEV_CHANGEMTU event to bypass changing mfs when
LAN MTU is changed if NETIF_F_FCOE_MTU is supported.
Signed-off-by: Yi Zou <yi.zou@intel.com>
Signed-off-by: Robert Love <robert.w.love@intel.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
diff --git a/drivers/scsi/fcoe/fcoe.h b/drivers/scsi/fcoe/fcoe.h
index ce7f60f..c578082 100644
--- a/drivers/scsi/fcoe/fcoe.h
+++ b/drivers/scsi/fcoe/fcoe.h
@@ -40,6 +40,12 @@
#define FCOE_MIN_XID 0x0000 /* the min xid supported by fcoe_sw */
#define FCOE_MAX_XID 0x0FFF /* the max xid supported by fcoe_sw */
+/*
+ * Max MTU for FCoE: 14 (FCoE header) + 24 (FC header) + 2112 (max FC payload)
+ * + 4 (FC CRC) + 4 (FCoE trailer) = 2158 bytes
+ */
+#define FCOE_MTU 2158
+
unsigned int fcoe_debug_logging;
module_param_named(debug_logging, fcoe_debug_logging, int, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(debug_logging, "a bit mask of logging levels");