From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vlad Yasevich Subject: Re: [PATCH v2 net] vlan: Mask off vlan acceleration features on vlan device. Date: Wed, 26 Mar 2014 20:53:12 -0400 Message-ID: <53337678.9050208@redhat.com> References: <1395865521-2318-1-git-send-email-vyasevic@redhat.com> <1395865711-3347-1-git-send-email-vyasevic@redhat.com> <20140326.171038.2150319831233512825.davem@davemloft.net> <20140326211504.GA21393@macbook.localnet> Reply-To: vyasevic@redhat.com Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: Patrick McHardy , David Miller Return-path: Received: from mx1.redhat.com ([209.132.183.28]:17859 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753291AbaC0AxR (ORCPT ); Wed, 26 Mar 2014 20:53:17 -0400 In-Reply-To: <20140326211504.GA21393@macbook.localnet> Sender: netdev-owner@vger.kernel.org List-ID: On 03/26/2014 05:15 PM, Patrick McHardy wrote: > On Wed, Mar 26, 2014 at 05:10:38PM -0400, David Miller wrote: >> From: Vlad Yasevich >> Date: Wed, 26 Mar 2014 16:28:31 -0400 >> >>> Some drivers incorrectly assign vlan acceleration features to >>> vlan_features thus causing issues for Q-in-Q vlan configurations. >>> Prevent this once and for all by masking off acceleration features >>> for vlan devices until such time as we support stacked acceleration. >>> >>> Signed-off-by: Vlad Yasevich >> >> So what if we do have chips that can offload Q-in-Q? Will we use >> a new flag? > > For 802.1ad that was the intention, using the NETIF_F_HW_VLAN_STAG_* flags. > But we can't really do that as we don't carry multiple vlan_tci in the skb. If the card advertises VLAN_STAG_*, then we'll offload that, but CTAG will have to be computed by software. More infrastructure is needed to support nested vlan offloads. -vlad