From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Kirsher Subject: Re: [net-next] e1000e: remove use of IP payload checksum Date: Sat, 30 Jun 2012 22:32:39 -0700 Message-ID: <1341120759.2632.25.camel@jtkirshe-mobl> References: <1341052528-2444-1-git-send-email-jeffrey.t.kirsher@intel.com> <1341092196.4852.43.camel@deadeye.wl.decadent.org.uk> <20120630.173752.1993136000245136259.davem@davemloft.net> Reply-To: jeffrey.t.kirsher@intel.com Mime-Version: 1.0 Content-Type: multipart/signed; micalg="pgp-sha512"; protocol="application/pgp-signature"; boundary="=-0INls/016s/ieiYrNhcw" Cc: ben@decadent.org.uk, bruce.w.allan@intel.com, netdev@vger.kernel.org, gospo@redhat.com, sassmann@redhat.com To: David Miller Return-path: Received: from mga11.intel.com ([192.55.52.93]:6426 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751132Ab2GAFcw (ORCPT ); Sun, 1 Jul 2012 01:32:52 -0400 In-Reply-To: <20120630.173752.1993136000245136259.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-ID: --=-0INls/016s/ieiYrNhcw Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Sat, 2012-06-30 at 17:37 -0700, David Miller wrote: > From: Ben Hutchings > Date: Sat, 30 Jun 2012 22:36:36 +0100 >=20 > > On Sat, 2012-06-30 at 03:35 -0700, Jeff Kirsher wrote: > >> From: Bruce Allan > >>=20 > >> Currently only used when packet split mode is enabled with jumbo frame= s, > >> IP payload checksum (for fragmented UDP packets) is mutually exclusive= with > >> receive hashing offload since the hardware uses the same space in the > >> receive descriptor for the hardware-provided packet checksum and the R= SS > >> hash, respectively. Users currently must disable jumbos when receive > >> hashing offload is enabled, or vice versa, because of this incompatibi= lity. > >> Since testing has shown that IP payload checksum does not provide any = real > >> benefit, just remove it so that there is no longer a choice between ju= mbos > >> or receive hashing offload but not both as done in other Intel GbE dri= vers > >> (e.g. e1000, igb). > >>=20 > >> Also, add a missing check for IP checksum error reported by the hardwa= re; > >> let the stack verify the checksum when this happens. > > [...] > >=20 > > The change to enable RX hashing in 3.4, with this odd restriction seems > > to have broken most existing systems using jumbo MTU on e1000e. None o= f > > the distro scripts or network management daemons will automatically > > change offload configuration before MTU; how could they know? > >=20 > > Therefore this needs to be fixed in 3.5 and 3.4.y, not net-next. >=20 > Agreed. Ok, I will prepare it for net and stable 3.4. I know it will require a backported patch for stable 3.4.y since the current patch only applied to net & net-next. Bruce was wanting to have it applied to net & stable, and I was not sure based on the patch content and description, so I that is why I submitted it for net-next. --=-0INls/016s/ieiYrNhcw Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAABCgAGBQJP7+D3AAoJEOVv75VaS+3OOD0QAIJA1iTSlvuv3p88CEarsyeD ceDAha6hJGcilhe3/98IC8XDD2FGJF+068UUoI4hB43Kc+T7JqoU5evKEnJwdIFN qO5QzIugPvOR82xQ/NHhr2xvuxThimNeMcBHvy/NVWDiQBpGOMt/fBin7X/aZDoz TkN4OEEv/lncA8ZDJoNiCaDM+mYLnjL8w13IouOgHNJmzCK70j65r8bPMGXQzvBi fDTMPWGG9iS7JK6Z9nuM237BpmYszYAxYHNMjJ8o9kXuJkX+BjicG/KU0VXw2ZbW nPdK+9PXfA5iVJl1otvmqiZVzelVurUgz+PVFnefSpSnzU+emfePzhdV59P4U/fm 4Wx7i9PMrdtptGUz8kI5JXnHS+xT2aMibXyCXb+YaDSMtNIGNzl7BLmMal31yIVb pgEeAg5Imt/72LG7u6xNJoodH8XBXKxDu3FVPRaqOV01lKd6vDkEROUGi5GK2rNv i23Sk2aJy5tJpJvcHRAG7xxj8w/3wmLX5TTpORIl46RtDZ5u3PB/D2f+cgu/PGd/ EKi6o68mmy0VxCnSFQBzOz1A3Xnw5q3rZVRsLBAC4FZQ9ks7mOjmVyYHQuJgqeSu bZiAFoUX++VALevayIT+21nZeFmsKvMUzpT69yuOtE2oL84yue5Xl5wH52Q5gvE/ EanXOJ+N4Oj7LUyDopER =UlfF -----END PGP SIGNATURE----- --=-0INls/016s/ieiYrNhcw--