From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH] net: allow netif_carrier to be called safely from IRQ Date: Fri, 22 Jul 2011 17:16:42 -0700 (PDT) Message-ID: <20110722.171642.1498051921735569337.davem@davemloft.net> References: <20110722212629.GA10833@electric-eye.fr.zoreil.com> <20110722150956.5b341488@nehalam.ftrdhcpuser.net> <20110722155356.5911225f@nehalam.ftrdhcpuser.net> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: romieu@fr.zoreil.com, greearb@candelatech.com, torvalds@linux-foundation.org, david@unsolicited.net, tj@kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org To: shemminger@vyatta.com Return-path: Received: from shards.monkeyblade.net ([198.137.202.13]:36284 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756459Ab1GWARs (ORCPT ); Fri, 22 Jul 2011 20:17:48 -0400 In-Reply-To: <20110722155356.5911225f@nehalam.ftrdhcpuser.net> Sender: netdev-owner@vger.kernel.org List-ID: From: Stephen Hemminger Date: Fri, 22 Jul 2011 15:53:56 -0700 > As reported by Ben Greer and Froncois Romieu. The code path in > the netif_carrier code leads it to try and disable > a late workqueue to reenable it immediately > netif_carrier_on > -> linkwatch_fire_event > -> linkwatch_schedule_work > -> cancel_delayed_work > -> del_timer_sync > > If __cancel_delayed_work is used instead then there is no > problem of waiting for running linkwatch_event. > > There is a race between linkwatch_event running re-scheduling > but it is harmless to schedule an extra scan of the linkwatch queue. > > Signed-off-by: Stephen Hemminger Applied.