Re: [PATCH v2 10/14] ixgbe: Update ixgbe to use new vlan accleration.

["Michał Mirosław" <mirqus@gmail.com>]

W dniu 26 października 2010 00:02 użytkownik John Fastabend
<john.r.fastabend@intel.com> napisał:
> On 10/25/2010 2:40 PM, Michał Mirosław wrote:
>> W dniu 25 października 2010 19:50 użytkownik Peter P Waskiewicz Jr
>> <peter.p.waskiewicz.jr@intel.com> napisał:
>>> On Fri, 2010-10-22 at 06:24 -0700, Michał Mirosław wrote:
>>>> 2010/10/21 Jesse Gross <jesse@nicira.com>:
>>>>> Make the ixgbe driver use the new vlan accleration model.
>>>> [...]
>>>>> --- a/drivers/net/ixgbe/ixgbe_main.c
>>>>> +++ b/drivers/net/ixgbe/ixgbe_main.c
>>>>> @@ -954,17 +954,13 @@ static void ixgbe_receive_skb(struct ixgbe_q_vector *q_vector,
>>>>>        bool is_vlan = (status & IXGBE_RXD_STAT_VP);
>>>>>        u16 tag = le16_to_cpu(rx_desc->wb.upper.vlan);
>>>>>
>>>>> -       if (!(adapter->flags & IXGBE_FLAG_IN_NETPOLL)) {
>>>>> -               if (adapter->vlgrp && is_vlan && (tag & VLAN_VID_MASK))
>>>>> -                       vlan_gro_receive(napi, adapter->vlgrp, tag, skb);
>>>>> -               else
>>>>> -                       napi_gro_receive(napi, skb);
>>>>> -       } else {
>>>>> -               if (adapter->vlgrp && is_vlan && (tag & VLAN_VID_MASK))
>>>>> -                       vlan_hwaccel_rx(skb, adapter->vlgrp, tag);
>>>>> -               else
>>>>> -                       netif_rx(skb);
>>>>> -       }
>>>>> +       if (is_vlan && (tag & VLAN_VID_MASK))
>>>>> +               __vlan_hwaccel_put_tag(skb, tag);
>>>>
>>>> I know that this is carried over from the driver, but why tag == 0 is
>>>> treated differently here? VID0 is somewhat special, as normally it
>>>> means 802.1p packet, but i.e. in embedded world people are using it as
>>>> normal VID. It would be nice to have this handled consistently in the
>>>> VLAN core - deliver to base dev (tag stripped) if vlan 0 is not
>>>> configured and to vlan dev if it is.
>>>
>>> ixgbe handles VLAN 0 differently because that's the tag that's used when
>>> DCB is enabled, and no VLAN is configured.  We have to insert the 802.1p
>>> tag for DCB to work, but the OS won't know about the 802.1q tag, and
>>> ends up dropping the frame.  So we enable VLAN ID 0 in the HW and tell
>>> it to strip the tag, so we can still pass the frame up the stack.
>>
>> So that's actually (part of) what I'm proposing but done at driver level.
> I agree this should be handled outside the driver. Something like this should
> do,

Current code (Linus' tree, so with Jesse's VLAN rework applied) should
work exactly as I proposed in my original mail - VLAN 0 is treated as
802.1p (stripped and delivered to original dev) unless vlan device
with id 0 is configured. (Patch untested).

Best Regards,
Michał Mirosław
---

ixgbe: Enable VLAN 0

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>

diff --git a/drivers/net/ixgbe/ixgbe_main.c b/drivers/net/ixgbe/ixgbe_main.c
index f856312..1544368 100644
--- a/drivers/net/ixgbe/ixgbe_main.c
+++ b/drivers/net/ixgbe/ixgbe_main.c
@@ -956,7 +956,7 @@ static void ixgbe_receive_skb(struct
ixgbe_q_vector *q_vector,
 	bool is_vlan = (status & IXGBE_RXD_STAT_VP);
 	u16 tag = le16_to_cpu(rx_desc->wb.upper.vlan);

-	if (is_vlan && (tag & VLAN_VID_MASK))
+	if (is_vlan)
 		__vlan_hwaccel_put_tag(skb, tag);

 	if (!(adapter->flags & IXGBE_FLAG_IN_NETPOLL))