Subject: Re: [PATCH]: sky2: Fix VLAN unregistration

From: Patrick McHardy <[email-masked]>
Date: Fri, 01 Jun 2007 17:16:24 +0200

Stephen Hemminger wrote:
> On Thu, 31 May 2007 19:37:07 +0200
> Patrick McHardy <[email-masked]> wrote:
> 
> 
>>Stephen Hemminger wrote:
>>
>>>On Sun, 27 May 2007 20:44:04 +0200
>>>Patrick McHardy <[email-masked]> wrote:
>>>
>>>
>>>
>>>>Fix sky2 disabling VLAN completely when the first vid is unregistered.
>>>>
>>>>For some reason the VLAN code insists on the driver providing a
>>>>vlan_rx_kill_vid function even if only NETIF_F_HW_VLAN_RX and not
>>>>NETIF_F_HW_VLAN_FILTER is set, so this patch keeps an empty
>>>>function. This seems to be a bug though, vlan_rx_add_vid is only
>>>>required with NETIF_F_HW_VLAN_FILTER. Ben?
>>>>
>>>
>>>
>>>Reading other drivers, it looks like a better patch would be to
>>>handle mode change in both set and kill.
>>
>>
>>The VLAN code tracks registered VIDs and will always call
>>vlan_rx_register(NULL) when the last VID is unregistered,
>>so this is not necessary.
>>
> 
> 
> Then should others be fixed...
> 	tg3, bnx2, r8169, gianfar, s2io, 8139cp, acenic, ...

tg3 and r8169 both look fine, they only unregister a single VID
within kill_vid and rely on VLAN to call rx_register(NULL) when
the group is unregistered (haven't looked at the others).

As I wrote in my previous mails, they do have a part that looks
unnecessary

        tg3_full_lock(tp, 0);
        vlan_group_set_device(tp->vlgrp, vid, NULL);

        tg3_full_unlock(tp);

since the vid is also removed by the VLAN code itself and locking
doesn't seem to be necessary because the VLAN hwaccel rx helper
deals with removal races itself.