From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753522AbaKLUbj (ORCPT ); Wed, 12 Nov 2014 15:31:39 -0500 Received: from na01-by1-obe.ptr.o365filtering.com ([64.4.22.94]:48476 "EHLO na01-by1-obe.outbound.o365filtering.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753190AbaKLUbh convert rfc822-to-8bit (ORCPT ); Wed, 12 Nov 2014 15:31:37 -0500 From: Haiyang Zhang To: David Miller CC: "netdev@vger.kernel.org" , KY Srinivasan , "olaf@aepfle.de" , "jasowang@redhat.com" , "linux-kernel@vger.kernel.org" , "driverdev-devel@linuxdriverproject.org" Subject: RE: [PATCH net-next] hyperv: Add processing of MTU reduced by the host Thread-Topic: [PATCH net-next] hyperv: Add processing of MTU reduced by the host Thread-Index: AQHP/f2e9z8vhEln9EShH6jS5e5RMpxd7OIA//977iCAAIkFgP//gSIg Date: Wed, 12 Nov 2014 20:31:17 +0000 Message-ID: References: <1415748472-27463-1-git-send-email-haiyangz@microsoft.com> <20141112.144640.703336197189868183.davem@davemloft.net> <20141112.150423.1660890641226643870.davem@davemloft.net> In-Reply-To: <20141112.150423.1660890641226643870.davem@davemloft.net> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-ms-exchange-transport-fromentityheader: Hosted x-originating-ip: [157.54.51.13] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 X-EOPAttributedMessage: 0 Authentication-Results: spf=pass (sender IP is 131.107.159.99) smtp.mailfrom=haiyangz@microsoft.com; aepfle.de; dkim=none (message not signed) header.d=none;aepfle.de; dmarc=pass action=none header.from=microsoft.com; X-Forefront-Antispam-Report: CIP:131.107.159.99;IPV:NLI;EFV:NLI;SFV:NSPM;SFS:(10019020)(189002)(51704005)(199003)(377454003)(164054003)(13464003)(107046002)(6806004)(84676001)(106116001)(87936001)(92566001)(50466002)(106466001)(76176999)(54356999)(50986999)(68736004)(97756001)(31966008)(66066001)(44976005)(19580405001)(19580395003)(86612001)(20776003)(47776003)(21056001)(64706001)(46102003)(584604001)(93886004)(99396003)(77096003)(110136001)(77156002)(46406003)(2656002)(62966003)(97736003)(4396001)(120916001)(108616004)(23726002)(33646002)(24736002);DIR:OUT;SFP:1102;SCL:1;SRVR:BL2SR01MB592;H:hybrid.exchange.microsoft.com;FPR:;SPF:Pass;PTR:InfoDomainNonexistent;MX:1;A:1;LANG:en; X-Microsoft-Antispam: UriScan:; X-Microsoft-Antispam: BCL:0;PCL:0;RULEID:;SRVR:BL2SR01MB592; X-DmarcAction: None X-DmarcStatus: Passed X-Exchange-Antispam-Report-Test: UriScan:; X-Forefront-PRVS: 03932714EB X-OriginatorOrg: msft.ccsctp.net Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > -----Original Message----- > From: David Miller [mailto:davem@davemloft.net] > Sent: Wednesday, November 12, 2014 3:04 PM > To: Haiyang Zhang > Cc: netdev@vger.kernel.org; KY Srinivasan; olaf@aepfle.de; > jasowang@redhat.com; linux-kernel@vger.kernel.org; driverdev- > devel@linuxdriverproject.org > Subject: Re: [PATCH net-next] hyperv: Add processing of MTU reduced by > the host > > From: Haiyang Zhang > Date: Wed, 12 Nov 2014 20:02:11 +0000 > > > The Hyper-V host doesn't support MTU below 1500. If we try setting MTU > to a > > value < 1500, the host will use 1500 automatically and return 1500 in > the > > RNDIS_OID_GEN_MAXIMUM_FRAME_SIZE query and guest will also use it. > That's > > why I set the lower limit to ETH_DATA_LEN. > > > > Are you suggesting that we keep the 68 as the lower limit, and let the > host > > auto-reset it to 1500 when we trying to set an MTU < 1500? > > Then you need to add a comment, because without any information or > context that change looks wrong. I will add a comment. Thanks, - Haiyang