gianfar: Revive VLAN support

commit 77ecaf2d5a8bfd548eed3f05c1c2e6573d5de4ba ("gianfar: Fix VLAN
HW feature related frame/buffer size calculation") wrongly removed
priv->vlgrp assignment, and now priv->vlgrp is always NULL.

This patch fixes the issue, plus fixes following sparse warning
introduced by the same commit:
gianfar.c:1406:13: warning: context imbalance in 'gfar_vlan_rx_register' - wrong count at exit

gfar_vlan_rx_register() checks for "if (old_grp == grp)" and tries
to return w/o dropping the lock.

According to net/8021q/vlan.c VLAN core issues rx_register() callback:
1. In register_vlan_dev() only on a newly created group;
2. In unregister_vlan_dev() only if the group becomes empty.

Thus the check in the gianfar driver isn't needed.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Acked-by: Andy Fleming <afleming@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 5 deletions

diff --git a/drivers/net/gianfar.c b/drivers/net/gianfar.c
index ea530673236e..3f7eab42aef1 100644
--- a/drivers/net/gianfar.c
+++ b/drivers/net/gianfar.c
@@ -1423,15 +1423,11 @@ static void gfar_vlan_rx_register(struct net_device *dev,
 {
         struct gfar_private *priv = netdev_priv(dev);
         unsigned long flags;
-        struct vlan_group *old_grp;
         u32 tempval;
 
         spin_lock_irqsave(&priv->rxlock, flags);
 
-        old_grp = priv->vlgrp;
-
-        if (old_grp == grp)
-                return;
+        priv->vlgrp = grp;
 
         if (grp) {
                 /* Enable VLAN tag insertion */