From: Shannon Nelson <shannon.nelson@oracle.com>
Date: Tue, 14 Mar 2017 17:24:43 +0000 (-0700)
Subject: sunvnet: xoff not needed when removing port link
X-Git-Tag: v4.14-rc1~960^3~422^2
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=9c5a3a1f9388100d4b03e85faf0cce8264985302;p=platform%2Fkernel%2Flinux-rpi.git

sunvnet: xoff not needed when removing port link

The sunvnet netdev is connected to the controlling ldom's vswitch
for network bridging.  However, for higher performance between ldoms,
there also is a channel between each client ldom.  These connections are
represented in the sunvnet driver by a queue for each ldom.  The driver
uses select_queue to tell the stack which queue to use by tracking the mac
addresses on the other end of each port.  When a connected ldom shuts down,
the driver receives an LDC_EVENT_RESET and the port is removed from the
driver, thus a queue with no ldom on the other end will never be selected
for Tx.

The driver was trying to reinforce the "don't use this queue" notion with
netif_tx_stop_queue() and netif_tx_wake_queue(), which really should only
be used to signal a Tx queue is full (aka XOFF).  This misuse of queue
state resulted in NETDEV WATCHDOG messages and lots of unnecessary calls
into the driver's tx_timeout handler.  Simply removing these takes care
of the problem.

Orabug: 25190537

Signed-off-by: Shannon Nelson <shannon.nelson@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/drivers/net/ethernet/sun/sunvnet_common.c b/drivers/net/ethernet/sun/sunvnet_common.c
index bf7e0fb..9e86833 100644
--- a/drivers/net/ethernet/sun/sunvnet_common.c
+++ b/drivers/net/ethernet/sun/sunvnet_common.c
@@ -1749,16 +1749,12 @@ void sunvnet_port_add_txq_common(struct vnet_port *port)
 	vp->nports++;
 	vp->q_used[smallest]++;
 	port->q_index = smallest;
-	netif_tx_wake_queue(netdev_get_tx_queue(VNET_PORT_TO_NET_DEVICE(port),
-						port->q_index));
 }
 EXPORT_SYMBOL_GPL(sunvnet_port_add_txq_common);
 
 void sunvnet_port_rm_txq_common(struct vnet_port *port)
 {
 	port->vp->nports--;
-	netif_tx_stop_queue(netdev_get_tx_queue(VNET_PORT_TO_NET_DEVICE(port),
-						port->q_index));
 	port->vp->q_used[port->q_index]--;
 	port->q_index = 0;
 }