Return-path: Received: from toccata.ens-lyon.org ([140.77.166.68]:43561 "EHLO toccata.ens-lyon.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755176AbaHYVcf (ORCPT ); Mon, 25 Aug 2014 17:32:35 -0400 Date: Mon, 25 Aug 2014 23:23:24 +0200 From: Samuel Thibault To: Sabrina Dubroca Cc: Valdis.Kletnieks@vt.edu, Hugh Dickins , Vincent Donnefort , Bryan Wu , linux-leds@vger.kernel.org, linux-kernel@vger.kernel.org, linux-wireless@vger.kernel.org Subject: Re: 3.17-rc1: leds blink workqueue causes sleeping BUGs Message-ID: <20140825212324.GC3070@type.youpi.perso.aquilenet.fr> (sfid-20140825_233255_870343_03EEA042) References: <10857.1408467967@turing-police.cc.vt.edu> <20140825211340.GA22168@kria> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 In-Reply-To: <20140825211340.GA22168@kria> Sender: linux-wireless-owner@vger.kernel.org List-ID: Hello, Sabrina Dubroca, le Mon 25 Aug 2014 23:13:40 +0200, a ?crit : > 2014-08-19, 13:06:07 -0400, Valdis.Kletnieks@vt.edu wrote: > > On Sat, 16 Aug 2014 20:27:01 -0700, Hugh Dickins said: > > > Can we safely revert your 8b37e1bef5a6 ("leds: convert blink timer to > > > workqueue"), or have there been other changes which now depend upon it? > > > > I suspect there's something else busted. I hand-reverted that patch, and I *still* > > see the following lockdep whine that looks related (as it talks about > > leddev_list_lock). next-0811 was OK, looks like next-0815 and -0818 had this.... > > I had a look at the code, led_trigger_event calls vt_led_set, which > calls led_trigger_event again. Yes, that is expected: the vt::* leds actually generate the corresponding vt-* trigger events, which are used by the various input*::* leds. We could indeed have a loop if the user was making the VT::* leds use the vt-* trigger, but otherwise it's safe since it's a different trigger. We can add code to prevent the user from building loops, but otherwise it's a false positive. Samuel