Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752007AbdLLI2v (ORCPT ); Tue, 12 Dec 2017 03:28:51 -0500 Received: from vps0.lunn.ch ([185.16.172.187]:57818 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751234AbdLLI2r (ORCPT ); Tue, 12 Dec 2017 03:28:47 -0500 Date: Tue, 12 Dec 2017 09:28:37 +0100 From: Andrew Lunn To: Sean Wang Cc: davem@davemloft.net, f.fainelli@gmail.com, vivien.didelot@savoirfairelinux.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mediatek@lists.infradead.org Subject: Re: [PATCH net-next 2/3] net: dsa: mediatek: combine MediaTek tag with VLAN tag Message-ID: <20171212082837.GM28672@lunn.ch> References: <20171207153016.GC24750@lunn.ch> <1513063281.28444.25.camel@mtkswgap22> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1513063281.28444.25.camel@mtkswgap22> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1499 Lines: 49 On Tue, Dec 12, 2017 at 03:21:21PM +0800, Sean Wang wrote: > On Thu, 2017-12-07 at 16:30 +0100, Andrew Lunn wrote: > > > @@ -25,20 +28,37 @@ static struct sk_buff *mtk_tag_xmit(struct sk_buff *skb, > > > { > > > struct dsa_port *dp = dsa_slave_to_port(dev); > > > u8 *mtk_tag; > > > + bool is_vlan_skb = true; > > > > .. > > > > > + /* Mark tag attribute on special tag insertion to notify hardware > > > + * whether that's a combined special tag with 802.1Q header. > > > + */ > > > + mtk_tag[0] = is_vlan_skb ? MTK_HDR_XMIT_TAGGED_TPID_8100 : > > > + MTK_HDR_XMIT_UNTAGGED; > > > mtk_tag[1] = (1 << dp->index) & MTK_HDR_XMIT_DP_BIT_MASK; > > > - mtk_tag[2] = 0; > > > - mtk_tag[3] = 0; > > > + > > > + /* Tag control information is kept for 802.1Q */ > > > + if (!is_vlan_skb) { > > > + mtk_tag[2] = 0; > > > + mtk_tag[3] = 0; > > > + } > > > > > > return skb; > > > } > > > > Hi Sean > > > > So you can mark a packet for egress. What about ingress? How do you > > know the VLAN/PORT combination for packets the CPU receives? I would > > of expected a similar change to mtk_tag_rcv(). > > > > Andrew > > Hi, Andrew > > It's unnecessary for extra handling in mtk_tag_rcv() when VLAN tag is > present since it is able to put the VLAN tag after the special tag and > then follow the existing way to parse. Hi Sean O.K. Please mention this in the commit message. Since it was something i was expecting, it should be documented why it is not needed. Thanks Andrew