Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759428AbXE2Qdv (ORCPT ); Tue, 29 May 2007 12:33:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754229AbXE2Qdo (ORCPT ); Tue, 29 May 2007 12:33:44 -0400 Received: from smtp1.linux-foundation.org ([207.189.120.13]:53491 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752973AbXE2Qdo (ORCPT ); Tue, 29 May 2007 12:33:44 -0400 Date: Tue, 29 May 2007 09:33:24 -0700 From: Andrew Morton To: Cc: , , , , Subject: Re: [2.6.22-rc1-mm1] ehci-hcd - BUG: scheduling while atomic: rmmod/0x00000001/4568 Message-Id: <20070529093324.92e571a0.akpm@linux-foundation.org> In-Reply-To: References: <20070521024437.GA4751@inferi.kami.home> <20070525214005.GA6925@suse.de> <20070525150015.b5eaafc3.akpm@linux-foundation.org> X-Mailer: Sylpheed 2.4.1 (GTK+ 2.8.17; x86_64-unknown-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2151 Lines: 66 On Tue, 29 May 2007 10:14:35 -0500 wrote: > > Sorry about that. Would it be helpful if I verified that and sent it in > signed off? > Yes please. The question in my mind was "did it add a race": say, the notifier chain gets called by some external source after we've gone and reset the device? > > -----Original Message----- > From: Andrew Morton [mailto:akpm@linux-foundation.org] > Sent: Friday, May 25, 2007 5:00 PM > To: Greg KH > Cc: Mattia Dongili; Linux Kernel Mailing List; Hayes, Stuart; David > Brownell; linux-usb-devel@lists.sourceforge.net > Subject: Re: [2.6.22-rc1-mm1] ehci-hcd - BUG: scheduling while atomic: > rmmod/0x00000001/4568 > > On Fri, 25 May 2007 14:40:05 -0700 Greg KH wrote: > > > On Mon, May 21, 2007 at 11:44:37AM +0900, Mattia Dongili wrote: > > > Hello, > > > > > > with gregkh-usb-usb-ehci-cpufreq-fix.patch removing ehci-hcd causes > > > the following BUG: > > > > Thanks for letting me know. > > > > Stuart, any help here? > > pretty obvious. cpufreq_unregister_notifier() sleeps, and that patch > causes it to be called under spinlock. > > Something like this... > > --- a/drivers/usb/host/ehci-hcd.c~fix-gregkh-usb-usb-ehci-cpufreq-fix > +++ a/drivers/usb/host/ehci-hcd.c > @@ -452,14 +452,14 @@ static void ehci_stop (struct usb_hcd *h > if (HC_IS_RUNNING (hcd->state)) > ehci_quiesce (ehci); > > -#ifdef CONFIG_CPU_FREQ > - cpufreq_unregister_notifier(&ehci->cpufreq_transition, > - CPUFREQ_TRANSITION_NOTIFIER); > -#endif > ehci_reset (ehci); > ehci_writel(ehci, 0, &ehci->regs->intr_enable); > spin_unlock_irq(&ehci->lock); > > +#ifdef CONFIG_CPU_FREQ > + cpufreq_unregister_notifier(&ehci->cpufreq_transition, > + CPUFREQ_TRANSITION_NOTIFIER); > +#endif > /* let companion controllers work when we aren't */ > ehci_writel(ehci, 0, &ehci->regs->configured_flag); > > _ - 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/