RDMA/nes: Fix SFP+ link down detection issue with switch port disable

In case of SFP+ PHY, link status check at interrupt processing can
give false results.  For proper link status change detection a delayed
recheck is needed to give nes registers time to settle.  Add a
periodic link status recheck scheduled at interrupt to detect
potential delayed registers state changes.

Addresses: http://bugs.openfabrics.org/bugzilla/show_bug.cgi?id=2117
Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/drivers/infiniband/hw/nes/nes_hw.h b/drivers/infiniband/hw/nes/nes_hw.h
index 8a9ea9a..d2abe07 100644
--- a/drivers/infiniband/hw/nes/nes_hw.h
+++ b/drivers/infiniband/hw/nes/nes_hw.h
@@ -1354,6 +1354,10 @@
 #define BAD_FRAME_OFFSET	64
 #define CQE_MAJOR_DRV		0x8000
 
+/* Used for link status recheck after interrupt processing */
+#define NES_LINK_RECHECK_DELAY	msecs_to_jiffies(50)
+#define NES_LINK_RECHECK_MAX	60
+
 #define nes_vlan_rx vlan_hwaccel_receive_skb
 #define nes_netif_rx netif_receive_skb