Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756348AbZCBXBq (ORCPT ); Mon, 2 Mar 2009 18:01:46 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753089AbZCBXBg (ORCPT ); Mon, 2 Mar 2009 18:01:36 -0500 Received: from yx-out-2324.google.com ([74.125.44.29]:30267 "EHLO yx-out-2324.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752860AbZCBXBf convert rfc822-to-8bit (ORCPT ); Mon, 2 Mar 2009 18:01:35 -0500 MIME-Version: 1.0 In-Reply-To: <200903012324.39327.rjw@sisk.pl> References: <200902221837.49396.rjw@sisk.pl> <200903012321.40328.rjw@sisk.pl> <200903012324.39327.rjw@sisk.pl> Date: Mon, 2 Mar 2009 15:01:33 -0800 Message-ID: Subject: Re: [RFC][PATCH 1/4] PM: Rework handling of interrupts during suspend-resume (rev. 4) From: =?ISO-8859-1?Q?Arve_Hj=F8nnev=E5g?= To: "Rafael J. Wysocki" Cc: LKML , Linus Torvalds , Ingo Molnar , "Eric W. Biederman" , Benjamin Herrenschmidt , Jeremy Fitzhardinge , pm list , Len Brown , Jesse Barnes , Thomas Gleixner , Alan Stern , Johannes Berg Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2618 Lines: 64 On Sun, Mar 1, 2009 at 2:24 PM, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki > > Introduce two helper functions allowing us to prevent device drivers > from getting any interrupts (without disabling interrupts on the CPU) > during suspend (or hibernation) and to make them start to receive > interrupts again during the subsequent resume, respectively. ?These > functions make it possible to keep timer interrupts enabled while the > "late" suspend and "early" resume callbacks provided by device > drivers are being executed. > > Use these functions to rework the handling of interrupts during > suspend (hibernation) and resume. ?Namely, interrupts will only be > disabled on the CPU right before suspending sysdevs, while device > drivers will be prevented from receiving interrupts, with the help of > the new helper function, before their "late" suspend callbacks run > (and analogously during resume). > > In addition, since the device interrups are now disabled before the > CPU has turned all interrupts off and the CPU will ACK the interrupts > setting the IRQ_PENDING bit for them, check in sysdev_suspend() if > any wake-up interrupts are pending and abort suspend if that's the > case. > > +void resume_device_irqs(void) > +{ > + ? ? ? struct irq_desc *desc; > + ? ? ? int irq; > + > + ? ? ? for_each_irq_desc(irq, desc) > + ? ? ? ? ? ? ? if (desc->status & IRQ_SUSPENDED) > + ? ? ? ? ? ? ? ? ? ? ? enable_irq(irq); > +} I think you need to clear IRQ_SUSPENDED here, not in enable_irq. > @@ -222,8 +222,9 @@ static void __enable_irq(struct irq_desc > ? ? ? ? ? ? ? ?WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n", irq); > ? ? ? ? ? ? ? ?break; > ? ? ? ?case 1: { > - ? ? ? ? ? ? ? unsigned int status = desc->status & ~IRQ_DISABLED; > + ? ? ? ? ? ? ? unsigned int status; > > + ? ? ? ? ? ? ? status = desc->status & ~(IRQ_DISABLED | IRQ_SUSPENDED); > ? ? ? ? ? ? ? ?/* Prevent probing on this irq: */ > ? ? ? ? ? ? ? ?desc->status = status | IRQ_NOPROBE; > ? ? ? ? ? ? ? ?check_irq_resend(desc, irq); This only clears IRQ_SUSPENDED if the interrupt was not disabled elsewhere. If a driver calls interrupt_disable in suspend_late, but calls interrupt_enable lazily, resume_device_irqs will reenable the interrupt even though the driver has a disable reference. The rest of the patch looks good. -- Arve Hj?nnev?g -- 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/