[PATCH] gianfar: Revive VLAN support

[Andy Fleming]

On Jan 26, 2009, at 2:50 PM, Anton Vorontsov wrote:

> 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 at ru.mvista.com>

Acked-by: Andy Fleming <afleming at freescale.com>