From mboxrd@z Thu Jan 1 00:00:00 1970 From: Francois Romieu Subject: Re: [PATCH 3/4] 8139too: RTNL and flush_scheduled_work deadlock Date: Fri, 16 Feb 2007 21:20:34 +0100 Message-ID: <20070216202034.GA10353@electric-eye.fr.zoreil.com> References: <20070215223744.GC19840@electric-eye.fr.zoreil.com> <20070216075936.GB1599@ff.dom.local> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: jeff@garzik.org, Stephen Hemminger , akpm@linux-foundation.org, netdev@vger.kernel.org, Ben Greear , Kyle Lucke , Raghavendra Koushik , Al Viro To: Jarek Poplawski Return-path: Received: from electric-eye.fr.zoreil.com ([213.41.134.224]:35008 "EHLO fr.zoreil.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1946130AbXBPU0x (ORCPT ); Fri, 16 Feb 2007 15:26:53 -0500 Content-Disposition: inline In-Reply-To: <20070216075936.GB1599@ff.dom.local> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Jarek Poplawski : [...] > > diff --git a/drivers/net/8139too.c b/drivers/net/8139too.c > > index 35ad5cf..99304b2 100644 > > --- a/drivers/net/8139too.c > > +++ b/drivers/net/8139too.c > > @@ -1109,6 +1109,8 @@ static void __devexit rtl8139_remove_one (struct pci_dev *pdev) > > > > assert (dev != NULL); > > > > + flush_scheduled_work(); > > + > > IMHO there should be rather cancel_rearming_delayed_work > instead of this. The delayed_work is initialized even if tp->have_thread is false, so cancel_rearming_delayed_work() will work, yes. Feel free to send a patch. [...] > > @@ -1603,18 +1605,21 @@ static void rtl8139_thread (struct work_struct *work) > > struct net_device *dev = tp->mii.dev; > > unsigned long thr_delay = next_tick; > > > > + rtnl_lock(); > > + > > + if (!netif_running(dev)) > > + goto out_unlock; > > I wonder, why you don't do netif_running before > rtnl_lock ? It's an atomic operation. And I'm not sure if increasing > rtnl_lock range is really needed here. thread A: netif_running() user task B: rtnl_lock() user task B: dev->close() user task B: rtnl_unlock() thread A: rtnl_lock() thread A: mess with closed device Btw, the thread runs every 3*HZ at most. -- Ueimor