From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jarek Poplawski Subject: Re: [Bug #14925] sky2 panic under load Date: Mon, 11 Jan 2010 13:26:47 +0000 Message-ID: <20100111132647.GA11193@ff.dom.local> References: <4B4A729E.9060805@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: "Rafael J. Wysocki" , netdev@vger.kernel.org To: "Berck E. Nash" Return-path: Received: from mail-fx0-f215.google.com ([209.85.220.215]:38499 "EHLO mail-fx0-f215.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753350Ab0AKN0z (ORCPT ); Mon, 11 Jan 2010 08:26:55 -0500 Received: by fxm7 with SMTP id 7so19766608fxm.29 for ; Mon, 11 Jan 2010 05:26:53 -0800 (PST) Content-Disposition: inline In-Reply-To: <4B4A729E.9060805@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: On Sun, Jan 10, 2010 at 05:36:46PM -0700, Berck E. Nash wrote: > Rafael J. Wysocki wrote: > > This message has been generated automatically as a part of a report > > of recent regressions. > > > > The following bug entry is on the current list of known regressions > > from 2.6.32. Please verify if it still should be listed and let me know > > (either way). BTW, I don't know why Berck didn't experience such a panic before 2.6.32, but seems not a regression to me. There might be new/more sky2 TX timeouts which trigger this panic and would make a real regression. Cheers, Jarek P. > > > > > > Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=14925 > > Subject : sky2 panic under load > > Submitter : Berck E. Nash > > Date : 2009-12-21 23:52 (21 days old) > > References : http://marc.info/?l=linux-kernel&m=126143955730347&w=4 > > http://marc.info/?l=linux-kernel&m=126160893126548&w=4 > > Handled-By : Stephen Hemminger > > The patch attached to the bug report did not fix the problem, but I'm > fairly certain that this one from Jarek P. did: > > During TX timeout procedure dev could be awoken too early, e.g. by > sky2_complete_tx() called from sky2_down(). Then sky2_xmit_frame() > can run while buffers are freed causing an oops. This patch fixes it > by adding netif_device_present() test in sky2_tx_complete(). > > Fixes: http://bugzilla.kernel.org/show_bug.cgi?id=14925 > > With debugging by: Mike McCormack > > Reported-by: Berck E. Nash > Tested-by: Berck E. Nash > Signed-off-by: Jarek Poplawski > > --- > > drivers/net/sky2.c | 3 ++- > 1 files changed, 2 insertions(+), 1 deletions(-) > > diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c > index 1c01b96..7650f73 100644 > --- a/drivers/net/sky2.c > +++ b/drivers/net/sky2.c > @@ -1844,7 +1844,8 @@ static void sky2_tx_complete(struct sky2_port > *sky2, u16 done) > sky2->tx_cons = idx; > smp_mb(); > > - if (tx_avail(sky2) > MAX_SKB_TX_LE + 4) > + /* Wake unless it's detached, and called e.g. from sky2_down() */ > + if (tx_avail(sky2) > MAX_SKB_TX_LE + 4 && netif_device_present(dev)) > netif_wake_queue(dev); > } >