From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752145Ab1EYSrJ (ORCPT ); Wed, 25 May 2011 14:47:09 -0400 Received: from smtprelay.restena.lu ([158.64.1.62]:37530 "EHLO smtprelay.restena.lu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750966Ab1EYSrH (ORCPT ); Wed, 25 May 2011 14:47:07 -0400 Date: Wed, 25 May 2011 20:46:48 +0200 From: Bruno =?UTF-8?B?UHLDqW1vbnQ=?= To: Fabio Erculiani Cc: linux-fbdev@vger.kernel.org, lethal@linux-sh.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] fbmem: fix race condition between register_framebuffer() and fb_open() Message-ID: <20110525204648.58983270@neptune.home> In-Reply-To: References: <1306266871-12464-1-git-send-email-lxnay@sabayon.org> <20110524224545.08c53b1d@neptune.home> <20110525181917.12cf97b8@neptune.home> X-Mailer: Claws Mail 3.7.9 (GTK+ 2.22.1; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 25 May 2011 Fabio Erculiani wrote: > I'm not a fbdev expert. So I leave the real fix to real men ( ;-) ). > It is causing deadlock during boot, so I would consider it quite critical. > Users using any fb driver will get into troubles. > The workaround is to boot with vga=normal. What is your system doing during boot? I've never seen it here but maybe my boot sequence is too simple. Could you tell if it deadlocks before init gets started or afterwards, which fb drivers (and extra kernel patches if any) are in use. If you have the complete backtrace of the deadlocked processes it would help getting a better idea of what is affected and how (and why just the framebuffer's lock is not causing trouble with earlier kernel versions). Bruno > Cheers,