From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jarek Poplawski Subject: Re: [PATCH] sky2: Lock transmit queue while disabling device Date: Thu, 31 Dec 2009 19:51:48 +0100 Message-ID: <4B3CF2C4.5070203@gmail.com> References: <4B3C8323.1080301@ring3k.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Stephen Hemminger , netdev@vger.kernel.org, flyboy@gmail.com, dhazelton@enter.net, mbreuer@majjas.com, Linux Netdev List To: Mike McCormack Return-path: Received: from mail-fx0-f225.google.com ([209.85.220.225]:47904 "EHLO mail-fx0-f225.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752594AbZLaSv5 (ORCPT ); Thu, 31 Dec 2009 13:51:57 -0500 Received: by fxm25 with SMTP id 25so6869451fxm.21 for ; Thu, 31 Dec 2009 10:51:55 -0800 (PST) In-Reply-To: <4B3C8323.1080301@ring3k.org> Sender: netdev-owner@vger.kernel.org List-ID: Mike McCormack wrote, On 12/31/2009 11:55 AM: > netif_device_detach() does not take the tx_lock, so it's > possible that a call to sky2_xmit_frame is still in > progress after netif_device_detach() is complete. > > Take netif_tx_lock() to make sure all transmits have > stopped while we're disabling the devices and that > no other CPU is still transmitting a frame after > we've disabling the device. > > Proposed fix for "sky2 panic under load" reported by Berck E. Nash. Could you give some scenario of the oops/fix? Btw, even if it worked, you should use netif_tx_lock_bh version considering sky2_detach use contexts, I guess. Jarek P. > > Signed-off-by: Mike McCormack > --- > drivers/net/sky2.c | 2 ++ > 1 files changed, 2 insertions(+), 0 deletions(-) > > diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c > index faa4841..8ae8520 100644 > --- a/drivers/net/sky2.c > +++ b/drivers/net/sky2.c > @@ -3176,7 +3176,9 @@ static void sky2_reset(struct sky2_hw *hw) > static void sky2_detach(struct net_device *dev) > { > if (netif_running(dev)) { > + netif_tx_lock(dev); > netif_device_detach(dev); /* stop txq */ > + netif_tx_unlock(dev); > sky2_down(dev); > } > }