From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DEF69C4332F for ; Sun, 8 Sep 2019 12:56:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B11A32081B for ; Sun, 8 Sep 2019 12:56:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567947385; bh=fbuhbY+84QNU6mdKZxyLD88VMblL578XwdT02sU+kjo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ilmgAuczXndF440om02rFbTq5MMImDzhxI9H4LLfvAGGKVg/Sx07S+aKqSpZfNmiq QyAFDwKayaYDash5j7ufC67rfkhJeY1g23u0uDUQwP8iJLophx/K3VN5xM1ZtvaBYr 7xYaPlrQ1J/TwGxETwWO9f2UROEuMvYf3iEnQsH4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731644AbfIHMtn (ORCPT ); Sun, 8 Sep 2019 08:49:43 -0400 Received: from mail.kernel.org ([198.145.29.99]:39824 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731624AbfIHMtk (ORCPT ); Sun, 8 Sep 2019 08:49:40 -0400 Received: from localhost (unknown [62.28.240.114]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id BA0C521A4C; Sun, 8 Sep 2019 12:49:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1567946980; bh=fbuhbY+84QNU6mdKZxyLD88VMblL578XwdT02sU+kjo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=itYqEfw2H0lOYyk6KfsBcsdQRIvs7OulkDyNwbDlLrd4ACySQJ4YmjxzfEWwFi3bq KzW7TcdqRaB7AiL/O7+nVeBp6nALeQy23WGW/HITnNHh9ZrdO4X/GyMSJav+a3O/4J gppUxWIZJxJpXM7AGJLq3TApQIC1bucueEXLi1PY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Vladimir Oltean , Florian Fainelli , "David S. Miller" Subject: [PATCH 5.2 16/94] net: dsa: tag_8021q: Future-proof the reserved fields in the custom VID Date: Sun, 8 Sep 2019 13:41:12 +0100 Message-Id: <20190908121150.897345047@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20190908121150.420989666@linuxfoundation.org> References: <20190908121150.420989666@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Vladimir Oltean [ Upstream commit bcccb0a535bb99616e4b992568371efab1ab14e8 ] After witnessing the discussion in https://lkml.org/lkml/2019/8/14/151 w.r.t. ioctl extensibility, it became clear that such an issue might prevent that the 3 RSV bits inside the DSA 802.1Q tag might also suffer the same fate and be useless for further extension. So clearly specify that the reserved bits should currently be transmitted as zero and ignored on receive. The DSA tagger already does this (and has always did), and is the only known user so far (no Wireshark dissection plugin, etc). So there should be no incompatibility to speak of. Fixes: 0471dd429cea ("net: dsa: tag_8021q: Create a stable binary format") Signed-off-by: Vladimir Oltean Reviewed-by: Florian Fainelli Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/dsa/tag_8021q.c | 2 ++ 1 file changed, 2 insertions(+) --- a/net/dsa/tag_8021q.c +++ b/net/dsa/tag_8021q.c @@ -28,6 +28,7 @@ * * RSV - VID[9]: * To be used for further expansion of SWITCH_ID or for other purposes. + * Must be transmitted as zero and ignored on receive. * * SWITCH_ID - VID[8:6]: * Index of switch within DSA tree. Must be between 0 and @@ -35,6 +36,7 @@ * * RSV - VID[5:4]: * To be used for further expansion of PORT or for other purposes. + * Must be transmitted as zero and ignored on receive. * * PORT - VID[3:0]: * Index of switch port. Must be between 0 and DSA_MAX_PORTS - 1.