From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Nelson Subject: Re: [PATCH 0/3] net: fec: updates to align IP header Date: Sat, 24 Sep 2016 08:29:10 -0700 Message-ID: References: <1474728139-9335-1-git-send-email-eric@nelint.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Cc: "linux@arm.linux.org.uk" , "andrew@lunn.ch" , "otavio@ossystems.com.br" , "edumazet@google.com" , "troy.kisky@boundarydevices.com" , "davem@davemloft.net" , "u.kleine-koenig@pengutronix.de" To: Andy Duan , "netdev@vger.kernel.org" Return-path: Received: from mail-pf0-f169.google.com ([209.85.192.169]:33091 "EHLO mail-pf0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750838AbcIXP3N (ORCPT ); Sat, 24 Sep 2016 11:29:13 -0400 Received: by mail-pf0-f169.google.com with SMTP id 21so51340778pfy.0 for ; Sat, 24 Sep 2016 08:29:12 -0700 (PDT) In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On 09/24/2016 08:09 AM, Andy Duan wrote: > From: Eric Nelson Sent: Saturday, September 24, 2016 10:42 PM >> To: netdev@vger.kernel.org >> Cc: linux@arm.linux.org.uk; andrew@lunn.ch; Andy Duan >> ; otavio@ossystems.com.br; >> edumazet@google.com; troy.kisky@boundarydevices.com; >> davem@davemloft.net; u.kleine-koenig@pengutronix.de; Eric Nelson >> >> Subject: [PATCH 0/3] net: fec: updates to align IP header >> >> This patch series is the outcome of investigation into very high numbers of >> alignment faults on kernel 4.1.33 from the linux-fslc >> tree: >> https://github.com/freescale/linux-fslc/tree/4.1-1.0.x-imx >> >> The first two patches remove support for the receive accelerator (RACC) >> from the i.MX25 and i.MX27 SoCs which don't support the function. >> >> The third patch enables hardware alignment of the ethernet packet payload >> (and especially the IP header) to prevent alignment faults in the IP stack. >> >> Testing on i.MX6UL on the 4.1.33 kernel showed that this patch removed on >> the order of 70k alignment faults during a 100MiB transfer using wget. >> >> Testing on an i.MX6Q (SABRE Lite) board on net-next (4.8.0-rc7) showed a >> much more modest improvement from 10's of faults, and it's not clear why >> that's the case. >> >> Eric Nelson (3): >> net: fec: remove QUIRK_HAS_RACC from i.mx25 >> net: fec: remove QUIRK_HAS_RACC from i.mx27 >> net: fec: align IP header in hardware >> >> drivers/net/ethernet/freescale/fec_main.c | 15 ++++++++++++--- >> 1 file changed, 12 insertions(+), 3 deletions(-) >> >> -- >> 2.7.4 > I will investigate the diff between 4.1 and 4.8. Thanks. > Thanks. Note that I'm not sure if the difference is 4.1 vs. 4.8 or i.MX6UL vs. i.MX6Q. > Acked-by: Fugang Duan >