From: Ganesh Goudar <ganeshgr@chelsio.com>
Date: Fri, 13 Jul 2018 17:56:55 +0530
Subject: cxgb4: do not return DUPLEX_UNKNOWN when link is down
Patch-mainline: v4.19-rc1
Git-commit: bc1b50309ce19bb2ccb1340fa83ab56ca6da8f96
References: bsc#1104279 FATE#325938 bsc#1127371

We were returning DUPLEX_UNKNOWN in get_link_ksettings() when
the link was down.  Unfortunately, this causes a problem when
"ethtool -s autoneg on" is issued for a link which is down because
the ethtool code first reads the settings and then reapplies them
with only the changes provided on the command line. Which results
in us diving into set_link_ksettings() with DUPLEX_UNKNOWN which is
not DUPLEX_FULL, so set_link_ksettings() throws an -EINVAL error.
do not return DUPLEX_UNKNOWN to fix the issue.

Signed-off-by: Casey Leedom <leedom@chelsio.com>
Signed-off-by: Ganesh Goudar <ganeshgr@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c |   11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

--- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_ethtool.c
@@ -628,13 +628,10 @@ static int get_link_ksettings(struct net
 	fw_caps_to_lmm(pi->port_type, pi->link_cfg.lpacaps,
 		       link_ksettings->link_modes.lp_advertising);
 
-	if (netif_carrier_ok(dev)) {
-		base->speed = pi->link_cfg.speed;
-		base->duplex = DUPLEX_FULL;
-	} else {
-		base->speed = SPEED_UNKNOWN;
-		base->duplex = DUPLEX_UNKNOWN;
-	}
+	base->speed = (netif_carrier_ok(dev)
+		       ? pi->link_cfg.speed
+		       : SPEED_UNKNOWN);
+	base->duplex = DUPLEX_FULL;
 
 	if (pi->link_cfg.fc & PAUSE_RX) {
 		if (pi->link_cfg.fc & PAUSE_TX) {