From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Greear Subject: Re: [PATCH v2 00/10] Low-level Ethernet debugging features. Date: Fri, 10 Feb 2012 09:18:59 -0800 Message-ID: <4F355183.2060704@candelatech.com> References: <1328730885-10941-1-git-send-email-greearb@candelatech.com> <4F349DB0.1010903@gmail.com> <4F34AE62.6070409@candelatech.com> <1328880345.2443.17.camel@edumazet-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: jeffrey.t.kirsher@intel.com, Jeff Kirsher , netdev@vger.kernel.org To: Eric Dumazet Return-path: Received: from mail.candelatech.com ([208.74.158.172]:57336 "EHLO ns3.lanforge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758243Ab2BJRTC (ORCPT ); Fri, 10 Feb 2012 12:19:02 -0500 In-Reply-To: <1328880345.2443.17.camel@edumazet-laptop> Sender: netdev-owner@vger.kernel.org List-ID: On 02/10/2012 05:25 AM, Eric Dumazet wrote: > Le jeudi 09 f=C3=A9vrier 2012 =C3=A0 21:42 -0800, Ben Greear a =C3=A9= crit : >> On 02/09/2012 08:31 PM, Jeff Kirsher wrote: >> >>> Thanks Ben! >>> >>> I have applied the series of 10 patches to my queue. I would like = to >>> have our validation team validate the e100, e1000 and e1000e patche= s >>> (and in-directly the net patches). >> >> Just in case you can generate errored frames other than ones with ju= st >> bad FCS, I'm curious to know if rx-all logic works with them. >> >> I was thinking I might could get at least some NICs to generate Runt= frames >> by sending small pkts and disabling frame padding, but haven't looke= d into >> it too hard yet. > > I am interested by this, do you know some NICs able to disable frame > padding ? It looks like e1000e driver can send frames at down to 32 bytes, which should be considered a runt. I think we'd just need to disable any padding in the software stacks (not sure it's there now or not), and th= en twiddle the 'PSP' but in the "Transmit Control Register". I'm not sure the best way to enable this feature up at user-space level= , but we could piggy-back on the no-fcs socket option and extend that flag to mean don't pad packets as well. Or, could add a new sock-opt perhaps. Thanks, Ben --=20 Ben Greear Candela Technologies Inc http://www.candelatech.com