Return-path: Received: from paleale.coelho.fi ([176.9.41.70]:45566 "EHLO farmhouse.coelho.fi" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751168AbdHXUAW (ORCPT ); Thu, 24 Aug 2017 16:00:22 -0400 Message-ID: <1503604818.15969.433.camel@coelho.fi> (sfid-20170824_220037_564955_EF43A5D1) From: Luca Coelho To: Jiri Kosina Cc: linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org, linuxwifi@intel.com, rui.zhang@intel.com, edubezval@gmail.com, linux-pm@vger.kernel.org, david.weinehall@intel.com, johannes.berg@intel.com, kvalo@codeaurora.org, sara.sharon@intel.com, emmanuel.grumbach@intel.com Date: Thu, 24 Aug 2017 23:00:18 +0300 In-Reply-To: References: <20170822073729.4856-1-luca@coelho.fi> <1503554432.15969.415.camel@coelho.fi> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Subject: Re: [PATCH v2] iwlwifi: pcie: move rx workqueue initialization to iwl_trans_pcie_alloc() Sender: linux-wireless-owner@vger.kernel.org List-ID: On Thu, 2017-08-24 at 21:56 +0200, Jiri Kosina wrote: > On Thu, 24 Aug 2017, Luca Coelho wrote: > > > > Work queues cannot be allocated when a mutex is held because the mutex > > > may be in use and that would make it sleep. Doing so generates the > > > following splat with 4.13+: > > > > > > [ 19.513298] ====================================================== > > > [ 19.513429] WARNING: possible circular locking dependency detected > > > [ 19.513557] 4.13.0-rc5+ #6 Not tainted > > > [ 19.513638] ------------------------------------------------------ > > > [ 19.513767] cpuhp/0/12 is trying to acquire lock: > > > [ 19.513867] (&tz->lock){+.+.+.}, at: [] thermal_zone_get_temp+0x5b/0xb0 > > > [ 19.514047] > > > [ 19.514047] but task is already holding lock: > > > [ 19.514166] (cpuhp_state){+.+.+.}, at: [] cpuhp_thread_fun+0x3a/0x210 > > > [ 19.514338] > > > [ 19.514338] which lock already depends on the new lock. > > > > > > This lock dependency already existed with previous kernel versions, > > > but it was not detected until commit 49dfe2a67797 ("cpuhotplug: Link > > > lock stacks for hotplug callbacks") was introduced. > > > > > > Reported-by: David Weinehall > > > Reported-by: Jiri Kosina > > > Signed-off-by: Luca Coelho > > > > Jiri, did you have a chance to try this out? I'm about to ask Kalle to > > merge this so it gets in in time for 4.13-rc7. > > Sorry, I am almost completely offline for one more week (vacation), and > will not have access to the affected system before that. Sounds good! Enjoy! ;) > But this indeed > looks like a correct fix to me, so feel free to add > > Acked-by: Jiri Kosina > > I'll be able to provide my Tested-by: eventually only in ~10 days. Kalle already picked it up in wireless-drivers and this should make it's way to 4.13-rc7 (we hope). In any case, thanks for reporting and the help debugging it. -- Cheers, Luca.