From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753109AbZDNGLU (ORCPT ); Tue, 14 Apr 2009 02:11:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751459AbZDNGLI (ORCPT ); Tue, 14 Apr 2009 02:11:08 -0400 Received: from earthlight.etchedpixels.co.uk ([81.2.110.250]:49768 "EHLO www.etchedpixels.co.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750983AbZDNGLH (ORCPT ); Tue, 14 Apr 2009 02:11:07 -0400 Date: Tue, 14 Apr 2009 07:12:04 +0100 From: Alan Cox To: Oliver Neukum Cc: Chuck Ebbert , linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org Subject: Re: Scheduling while atomic in tty code with cdc-acm driver, kernel 2.6.29.1 Message-ID: <20090414071204.2450b6a0@lxorguk.ukuu.org.uk> In-Reply-To: <200904140150.10790.oliver@neukum.org> References: <20090413193633.33ce0710@dhcp-100-2-144.bos.redhat.com> <200904140150.10790.oliver@neukum.org> X-Mailer: Claws Mail 3.7.0 (GTK+ 2.14.7; x86_64-redhat-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 Tue, 14 Apr 2009 01:50:10 +0200 Oliver Neukum wrote: > Am Dienstag 14 April 2009 01:36:33 schrieb Chuck Ebbert: > > BUG: sleeping function called from invalid context at kernel/mutex.c:88 > > in_atomic(): 1, irqs_disabled(): 0, pid: 0, name: swapper > > Pid: 0, comm: swapper Not tainted 2.6.29.1-54.fc11.x86_64 #1 > > Is this specific to 2.6.29.1? It looks like setting low_latency, as cdc-acm, > does for legacy reasons, is harmful now. Please remove these lines: The only thing that has changed is that this incorrect behaviour (setting low_latency and doing a flip_buffer_push() in IRQ context) now causes a warn rather than random failure. The hack setting of it for high data rate devices was obsolete when the tty buffer changes went in so it can definitely go in those cases.