netdev - Re: [PATCH net] bna: don't disable VLAN tag stripping in promisc mode

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Date:	Fri, 28 Feb 2014 07:31:42 +0100
From:	Jiri Pirko <jiri@...nulli.us>
To:	David Miller <davem@...emloft.net>
Cc:	ivecera@...hat.com, netdev@...r.kernel.org, rmody@...cade.com
Subject: Re: [PATCH net] bna: don't disable VLAN tag stripping in promisc mode

Thu, Feb 27, 2014 at 11:24:03PM CET, davem@...emloft.net wrote:
>From: Ivan Vecera <ivecera@...hat.com>
>Date: Thu, 27 Feb 2014 19:17:22 +0100
>
>> The recent commit "fe1624c bna: RX Filter Enhancements" disables
>> VLAN tag stripping if the NIC is in promiscuous mode. Received VLAN tagged
>> packets are recognized by the driver via BNA_CQ_EF_VLAN flag and for such
>> packets the driver calls __vlan_hwaccel_put_tag(). The problem is the HW
>> marks the tagged packets with this flags also when the stripping is
>> disabled and thus __vlan_hwaccel_put_tag() should not be called for them.
>> 
>> A solution can be to call __vlan_hwaccel_put_tag() only when stripping is
>> enabled or to leave VLAN stripping engine enabled. The 2nd restores the
>> previous behavior and is IMHO better.
>> 
>> Cc: Rasesh Mody <rmody@...cade.com>
>> Signed-off-by: Ivan Vecera <ivecera@...hat.com>
>
>At best, this is an incomplete change, because if we fix it like this
>then the stripping enable/disable functions are completely unused and
>therefore should be removed from the driver.
>
>But I really thing that checking if stripping is enabled at the
>__vlan_hwaccel_put_tag() call site is the best solution.
>
>You just need to check rxf->vlan_strip_status in addition to the
>descriptor flag.
>
>Please implement it this way, thanks.

Dave, do you think that enabling/disabling of vlan stripping should
depend on promisc on/off? That seems very odd to me...

Jiri

>
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