[PATCH 4.17 101/324] cxgb4: when disabling dcb set txq dcb priority to 0

[Greg Kroah-Hartman]

4.17-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Ganesh Goudar <ganeshgr@xxxxxxxxxxx>

[ Upstream commit 5ce36338a30f9814fc4824f9fe6c20cd83d872c7 ]

When we are disabling DCB, store "0" in txq->dcb_prio
since that's used for future TX Work Request "OVLAN_IDX"
values. Setting non zero priority upon disabling DCB
would halt the traffic.

Reported-by: AMG Zollner Robert <robert@xxxxxxxxxxxxx>
CC: David Ahern <dsa@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Casey Leedom <leedom@xxxxxxxxxxx>
Signed-off-by: Ganesh Goudar <ganeshgr@xxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
@@ -263,7 +263,7 @@ static void dcb_tx_queue_prio_enable(str
 				"Can't %s DCB Priority on port %d, TX Queue %d: err=%d\n",
 				enable ? "set" : "unset", pi->port_id, i, -err);
 		else
-			txq->dcb_prio = value;
+			txq->dcb_prio = enable ? value : 0;
 	}
 }