Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753460Ab3J3LUr (ORCPT ); Wed, 30 Oct 2013 07:20:47 -0400 Received: from bear.ext.ti.com ([192.94.94.41]:34846 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752870Ab3J3LUp (ORCPT ); Wed, 30 Oct 2013 07:20:45 -0400 Message-ID: <5270EB85.1030103@ti.com> Date: Wed, 30 Oct 2013 13:20:37 +0200 From: Tomi Valkeinen User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.0 MIME-Version: 1.0 To: Gu Zheng , Jean-Christophe PLAGNIOL-VILLARD CC: Linux Fbdev development list , linux-kernel Subject: Re: [RFC PATCH RESEND] fb: reorder the lock sequence to fix a potential lockdep References: <526DFDA8.7010806@cn.fujitsu.com> In-Reply-To: <526DFDA8.7010806@cn.fujitsu.com> X-Enigmail-Version: 1.6 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="dfiQb3TWVNumgxRMhjITDr4I4crUv1apa" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2223 Lines: 58 --dfiQb3TWVNumgxRMhjITDr4I4crUv1apa Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Hi, On 2013-10-28 08:01, Gu Zheng wrote: > Following commits: > 50e244cc79 fb: rework locking to fix lock ordering on takeover > e93a9a8687 fb: Yet another band-aid for fixing lockdep mess > 054430e773 fbcon: fix locking harder >=20 > reworked locking to fix related lock ordering on takeover, and introduc= ed console_lock > into fbmem, but it seems that the new lock sequence(fb_info->lock ---> = console_lock) > is against with the one in console_callback(console_lock ---> fb_info->= lock), and leads to > a potential deadlock as following: A quick grep shows that there are other places than fbmem.c which use lock_fb_info and console_lock, for example drivers/video/sh_mobile_lcdcfb= =2Ec. Tomi --dfiQb3TWVNumgxRMhjITDr4I4crUv1apa Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.14 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQIcBAEBAgAGBQJScOuFAAoJEPo9qoy8lh71nTMP/0LXtkpHctkUogDJZHlE14Gf 8xMRFtHFauyf950HUCro4VJ+vf3PaLQXK5LPJAzY8VnCkQUBZGEGiOrh7u13tK4O nocFMebEp6EJ5NVQwEb5SzTwpi6eNB7drhsJYHegM6Yi/tzMS/KnmL0OUGVAlKTq fUG1wIxam0ZzCDUsgi6FJZGS/6oCXi7rF6RAbZKf52P1X8Ea59bGahtuA+86PCla m9j0TnNTPfsvSTT2FkytxVMapa3spb+2aJOrX5+E73dW8MqdcIJIxDXJ0GJwbVwI y2CQjmOM2vJRkGuCZDlUbrI3w8Pw8N8qCRpaSawdVtckdkrXYPLUVkQmVLEMgux+ ioTSedlNdyisvr+ql2SONIfPtliRKOR2tw87udDhKM/SeCoUDCik95Nr+OEVPL/p 7NOw6AAfesKqkROFjRnEA+TJ3B8BnB5YfNr2lNwsKFJNASiUjjrXXuyXX1AfglnK DToaM9ys+hmYqOvTf8aFEuvZc79mQ17Tj+nCPvZIzuTfyltofyy5FWEc0EnYEK9M 4VbYWShHrlQh5hXFxbaL7DN5wViuROxgOZFYN2ZAMdAWOiIf5G/aajk3LsPpK5CK m5+ygae6Hy+ELAP5+VXoQfpc3lnPfB2N72fHNFCVBapwVKKwut3H5PGKwdNLgBLJ qz5/W8fQFaVxYG/mf3iR =XuwQ -----END PGP SIGNATURE----- --dfiQb3TWVNumgxRMhjITDr4I4crUv1apa-- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/