From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johannes Berg Subject: Re: lockdep report at resume Date: Fri, 20 Mar 2009 15:39:57 +0100 Message-ID: <1237559997.5100.159.camel@johannes.local> References: <1234022517.4175.107.camel@johannes.local> <1237536764.5100.124.camel@johannes.local> Mime-Version: 1.0 Content-Type: multipart/signed; micalg="pgp-sha1"; protocol="application/pgp-signature"; boundary="=-sDQBNVdRw0l98v+bo5Cm" Return-path: Received: from xc.sipsolutions.net ([83.246.72.84]:43265 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751315AbZCTOkD (ORCPT ); Fri, 20 Mar 2009 10:40:03 -0400 In-Reply-To: Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: Jiri Kosina Cc: Dmitry Torokhov , linux-input --=-sDQBNVdRw0l98v+bo5Cm Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Fri, 2009-03-20 at 15:37 +0100, Jiri Kosina wrote: > On Fri, 20 Mar 2009, Johannes Berg wrote: >=20 > > > [20920.458587] =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > > > [20920.458944] [ INFO: possible circular locking dependency detected = ] > > > [20920.459231] 2.6.29-rc3-wl-12787-g17d9115-dirty #38 > > > [20920.459449] ------------------------------------------------------= - > > > [20920.459736] events/0/9 is trying to acquire lock: > > > [20920.459951] (&dev->mutex){--..}, at: [] input_d= isconnect_device+0x2c/0xf0 > > > [20920.460369]=20 > > > [20920.460370] but task is already holding lock: > > > [20920.460637] (&usbhid->reset_work){--..}, at: []= run_workqueue+0xb3/0x250 > > > [20920.461049]=20 > > > [20920.461050] which lock already depends on the new lock. > > Ping? I just ran into it again on 2.6.29-rc8-wl-18593-gef1cb6f-dirty. >=20 > I haven't still fully gone through the whole dependency chain, was quite=20 > overloaded lately, sorry. >=20 > There is a patch from Oliver Neukum, that fixes workqueue usage semantics= =20 > around hid_reset() on [1], could you please check whether it also fixes=20 > the report you are seeing? Thanks. I can't seem to reproduce this completely reliably for some reason (or it's because my own development sometimes runs into lock problems elsewhere and lockdep disables itself), but I'll try to find a way to reproduce it and test the patch, thanks. johannes --=-sDQBNVdRw0l98v+bo5Cm Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Comment: Johannes Berg (powerbook) iQIcBAABAgAGBQJJw6q6AAoJEKVg1VMiehFYblEQALTSPLXg/ZgSJn31dIrn5yRi F8i9YuF858wb5XFqyDn66jT2BIPIrgG+KbGF9SwZVGDGf29r7lRuQILZtYItI1u+ z7zS9VQjro6KmVTAOeu315gxLyrGtJEr8lfsZizSDPtfnLMy6DriKbHuvOjFUKkG 6tfsROR63fzsnUe1rJcuO3FMlLK+8/wQdyJkm+JBryFM9cXU4KIlZ/2LZLPwq6Xq lFaQOFEsRHuUokcdzNRTDE08yHghS5PUeNn95Nz1TMV5NzQZAD2eaRZ7yk+S3Nq0 Cvs/N645eT9QPoVhvy6Nuc6kjiPIeySawjPh39ZQm0anedF7zgUGn6FV75Suob0/ oLd8wiJadvW8QBFJS22U3jOR0A7GyBwSeh8TLzP38uyPYcncLNCadQts6uzAcAQ4 uOhr47EqKgP+lf36VE58cbBLlt6GXolS3AbzoGYKg2MrUsv4FEcdEvrWhsRfBhKC XZWam6JuFcY4Gu7YyLm1tmjKUz6lKfKS3O644vOKbuHFS1DS/zRS25Gk3G2ethAg pHVnr7aicRWl2L9RK428mWBnYQaeHBdGBsG4EkWIZznA/Ly07VEuEg3rUpfVx61u /QXHbLg0tQApLVPClpUNAhSwasQlJ5po4Sd17zivwS8kqvhZL31ItsGlWQjbekbQ vFgnkWtAike1/YuvBX3R =jlvk -----END PGP SIGNATURE----- --=-sDQBNVdRw0l98v+bo5Cm--