From mboxrd@z Thu Jan 1 00:00:00 1970 From: figo zhang Subject: Re: KS8695: possible NAPI issue Date: Fri, 5 Mar 2010 14:54:44 +0800 Message-ID: References: <4B8D1C02.1010204@softplc.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Dick Hollenbeck , netdev@vger.kernel.org, zealcook@gmail.com To: Yegor Yefremov Return-path: Received: from mail-iw0-f186.google.com ([209.85.223.186]:58700 "EHLO mail-iw0-f186.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754036Ab0CEGyp convert rfc822-to-8bit (ORCPT ); Fri, 5 Mar 2010 01:54:45 -0500 Received: by iwn16 with SMTP id 16so2415701iwn.20 for ; Thu, 04 Mar 2010 22:54:44 -0800 (PST) In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: 2010/3/4 Yegor Yefremov : >>>> I'm using 2.6.33 kernel and I noticed such a strange behavior: >>>> >>>> after system start I transfer one file via netcat from my developm= ent >>>> host, after this transfer the network is not functioning i.e. no p= ings >>>> possible etc. >>>> >>>> To narrow down the problem I checked out this commit >>>> >>>> http://git.kernel.org/?p=3Dlinux/kernel/git/torvalds/linux-2.6.git= ;a=3Dcommit;h=3D451f14439847db302e5104c44458b2dbb4b1829d. >>>> Till here the network driver is functioning as intended, but after >>>> NAPI introduction I have this issue. With latest git-pull of "Linu= s' >>>> kernel tree" I can't even ping right after the systems start. >>>> >>>> Any Ideas? What am I missing? >>>> >>> >>> No idea, although I am using the same ARM chip, my kernel is at 2.6= =2E30.5, >>> and except for this occasional loss of connection I get, the ethern= et driver >>> seems to work better than what you are reporting. >> >> from linux-2.6.32, this ethernet =A0driver have add NAPI support, wo= uld >> you like to >> try using this version? > > Figo, I just looked at the 2.6.32 kernel and found out that it > doesn't' contain NAPI support (see the history > http://git.kernel.org/?p=3Dlinux/kernel/git/stable/linux-2.6.32.y.git= ;a=3Dhistory;f=3Ddrivers/net/arm/ks8695net.c;h=3D2a7b7745cc55b54cefada6= 90b0ea47865b54b6b9;hb=3DHEAD). > So 2.6.33 is the first stable kernel to support NAPI. > > I made some further tests but I can't find the reason for network > failures: the interrupts are coming and the packets will be received > and sent so that rx/tx counters would be increased, but none of them > seem to reach the IP stack. I don't know where and why the things get > desynchronized. > > Could you try the 2.6.33 or Linus tree? Thank you in advance. yes, i have test it on linux-2.6.33, it is work well.