bnx2x: Fix receiving tx-timeout in error or recovery state.

Driver performs the internal reload when it receives tx-timeout event from
the OS. Internal reload might fail in some scenarios e.g., fatal HW issues.
In such cases OS still see the link, which would result in undesirable
functionalities such as re-generation of tx-timeouts.
The patch addresses this issue by indicating the link-down to OS when
tx-timeout is detected, and keeping the link in down state till the
internal reload is successful.

Please consider applying it to 'net' branch.
Signed-off-by: Sudarsana Reddy Kalluru <Sudarsana.Kalluru@cavium.com>
Signed-off-by: Ariel Elior <ariel.elior@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bnx2x/bnx2x.h

@@ -1533,6 +1533,7 @@ struct bnx2x {
 	struct link_vars	link_vars;
 	u32			link_cnt;
 	struct bnx2x_link_report_data last_reported_link;
+	bool			force_link_down;
 
 	struct mdio_if_info	mdio;
 

drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c

@@ -1261,6 +1261,11 @@ void __bnx2x_link_report(struct bnx2x *bp)
 {
 	struct bnx2x_link_report_data cur_data;
 
+	if (bp->force_link_down) {
+		bp->link_vars.link_up = 0;
+		return;
+	}
+
 	/* reread mf_cfg */
 	if (IS_PF(bp) && !CHIP_IS_E1(bp))
 		bnx2x_read_mf_cfg(bp);
@@ -2817,6 +2822,7 @@ int bnx2x_nic_load(struct bnx2x *bp, int load_mode)
 		bp->pending_max = 0;
 	}
 
+	bp->force_link_down = false;
 	if (bp->port.pmf) {
 		rc = bnx2x_initial_phy_init(bp, load_mode);
 		if (rc)

drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c

@@ -10279,6 +10279,12 @@ static void bnx2x_sp_rtnl_task(struct work_struct *work)
 		bp->sp_rtnl_state = 0;
 		smp_mb();
 
+		/* Immediately indicate link as down */
+		bp->link_vars.link_up = 0;
+		bp->force_link_down = true;
+		netif_carrier_off(bp->dev);
+		BNX2X_ERR("Indicating link is down due to Tx-timeout\n");
+
 		bnx2x_nic_unload(bp, UNLOAD_NORMAL, true);
 		/* When ret value shows failure of allocation failure,
 		 * the nic is rebooted again. If open still fails, a error