From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michael Cronenworth Subject: e1000e max frame calculation Date: Mon, 06 Apr 2015 11:38:29 -0500 Message-ID: <5522B685.2030104@cchtml.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit To: netdev@vger.kernel.org Return-path: Received: from que31.charter.net ([209.225.8.23]:57818 "EHLO que31.charter.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750891AbbDFR1g (ORCPT ); Mon, 6 Apr 2015 13:27:36 -0400 Received: from imp09 ([10.20.200.9]) by mta31.charter.net (InterMail vM.8.01.05.02 201-2260-151-103-20110920) with ESMTP id <20150406163830.FPVK10321.mta31.charter.net@imp09> for ; Mon, 6 Apr 2015 12:38:30 -0400 Received: from impout002 ([68.114.189.17]) by mtaout006.msg.strl.va.charter.net (InterMail vM.9.00.015.01 201-2473-143-101) with ESMTP id <20150406163830.OGNR22086.mtaout006.msg.strl.va.charter.net@impout002> for ; Mon, 6 Apr 2015 11:38:30 -0500 Received: from mcronenworth.nhsrx.com (unknown [63.237.119.62]) by cchtml.com (Postfix) with ESMTPSA id B0618154019B for ; Mon, 6 Apr 2015 11:38:29 -0500 (CDT) Sender: netdev-owner@vger.kernel.org List-ID: Hello, I have attempted to discuss this with upstream directly[1], but they will not respond to me. I will now attempt here. The e1000e driver uses a different maximum frame calculation after a commit[2] in kernel 3.15. This caused everyone's setups that were using 9000 for MTU to break after they rebooted on their kernel update. The addition of the VLAN bytes force users to use 8996. Other drivers appear to be using the "old" maximum frame calculation and can continue to use 9000. Can a standard be decided upon that all drivers use or is it acceptable that one driver "does its own thing?" Thanks, Michael [1] https://sourceforge.net/p/e1000/bugs/459/ [2] https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/drivers/net/ethernet/intel/e1000e/netdev.c?id=c751a3d58cf2dae89ec941a259025b0175d67b0c