From mboxrd@z Thu Jan 1 00:00:00 1970 From: Emil Micek Subject: change the way e1000 is handling short VLAN frames Date: Fri, 21 Sep 2007 09:31:45 +0200 Message-ID: <1190359905.3551.28.camel@magi.nadr> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit To: netdev@vger.kernel.org Return-path: Received: from proxy-sec.valachnet.cz ([212.71.149.219]:45551 "EHLO proxy.valachnet.cz" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753572AbXIUIYh (ORCPT ); Fri, 21 Sep 2007 04:24:37 -0400 Received: from aula.nadr (pc10.valachnet.cz [212.71.186.10]) by proxy.valachnet.cz (8.13.1/8.13.1) with ESMTP id l8L7Vjf9012355 for ; Fri, 21 Sep 2007 09:31:45 +0200 Received: from [192.168.1.242] ([192.168.1.242]) (authenticated bits=0) by aula.nadr (8.13.1/8.13.1) with ESMTP id l8L7VjPU028302 (version=TLSv1/SSLv3 cipher=RC4-MD5 bits=128 verify=NO) for ; Fri, 21 Sep 2007 09:31:45 +0200 Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Hello list, I'd like to change behaviour of e1000 module when transmiting short ethernet frames (shorter then 64 bytes) trough VLAN interface. Current e1000 (according to our observations) first appends 4 bytes of VLAN tag and then pads the frame to 64 bytes with zeroes if necessary before transmiting it. I'd like to change it so it first pads the frame to 64 B and appends the VLAN tag afterwards, so the resulting VLAN frame would be 68 bytes minimum. I want to do it because C3 CMTS from arris, which is connected to our linux box, has problems handling VLAN frames shorter then 68 bytes. As i'm quite a newbie concerning linux sources and c programing, i'd like to ask you if this'd be trivial or complex change and if someone can point out relevant portions of the sources, where the necessary changes should be done. Regards Emil Micek