From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753960AbZEVC7Y (ORCPT ); Thu, 21 May 2009 22:59:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752222AbZEVC7E (ORCPT ); Thu, 21 May 2009 22:59:04 -0400 Received: from mail-qy0-f122.google.com ([209.85.221.122]:50801 "EHLO mail-qy0-f122.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754899AbZEVC7C convert rfc822-to-8bit (ORCPT ); Thu, 21 May 2009 22:59:02 -0400 X-Greylist: delayed 355 seconds by postgrey-1.27 at vger.kernel.org; Thu, 21 May 2009 22:59:01 EDT DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=Y3vDEMvLpP9RM5s9vTUW8TU3iOS+JhpokZJRyGVvWyjwGhRQUDM5JkOb1cYxjAQtWW 9FhlJHfo/BSl0bvJHJDybO29DmdeBzmLnMdkwbUjXlhyG/LFdOrz6Xae1ae9z+HsTIq/ +5xwuWqCd9ErHge9QHRZ1v/frzSLrdUfxB6wU= MIME-Version: 1.0 In-Reply-To: <200905060127.24777.rjw@sisk.pl> References: <1241483224-7113-1-git-send-email-khilman@deeprootsystems.com> <87eiv35eg6.fsf@deeprootsystems.com> <200905060127.24777.rjw@sisk.pl> Date: Fri, 22 May 2009 11:53:07 +0900 Message-ID: <4d34a0a70905211953r1138a554w3b7aa99770ba15e2@mail.gmail.com> Subject: Re: [PATCH] PM: suspend_device_irqs(): don't disable wakeup IRQs From: Kim Kyuwon To: "Rafael J. Wysocki" Cc: Andrew Morton , linux-pm@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Ingo Molnar , Kyungmin Park 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 On Wed, May 6, 2009 at 8:27 AM, Rafael J. Wysocki wrote: > On Wednesday 06 May 2009, Kevin Hilman wrote: >> Arve Hjønnevåg writes: >> >> > On Tue, May 5, 2009 at 8:52 AM, Kevin Hilman >> > wrote: >> >> Andrew Morton writes: >> >> >> >>> On Mon,  4 May 2009 17:27:04 -0700 Kevin Hilman wrote: >> >>> >> >>>> Interrupts that are flagged as wakeup sources via set_irq_wake() >> >>>> should not be disabled for suspend. >> >>>> >> >>> >> >>> Why not? >> >>> >> >> >> >> If an interrupt is a wakeup source, and it is disabled at the chip >> >> level, it will no longer generate interrupts, and thus no longer wake >> >> up the system. >> >> >> >> I'd be interested in hearing why wakeup interrupts should be disabled >> >> during suspend. > > That depends on whether or not they are used for anything else than wake-up. > >> >> [...] >> >> >>> >> >>> If this fixes some bug then please provide a description of that bug? >> >> >> >> The bug is that on TI OMAP, interrupts that are used for wakeup events >> >> are disabled by this code causing the system to no longer wake up. >> > >> > What do you do if the interrupt triggers right after your driver has >> > returned from its late suspend hook? >> >> If it's a wakeup IRQ, I assume you want it to prevent suspend. >> >> But I don't see how that can happen in the current code. IIUC, by the >> time your late suspend hook is run, your device IRQ is already >> disabled, so it won't trigger an interrupt that will be caught by >> check_wakeup_irqs() anyways. > > My understanding of __disable_irq() was that it didn't actually disable the > IRQ at the hardware level, allowing the CPU to actually receive the interrupt > and acknowledge it, but preventing the device driver for receiving it.  Does > it work differently on the affected systems? Hi, Rafael. Sorry for bring the old issue but please let me ask you about suspend_device_irqs() function. __disable_irq() disables the IRQ at the hardware level in the following irq_chips i8259A_chip i8259_pic i8259A_chip bfin_internal_irqchip crisv10_irq_type crisv32_irq_type h8300irq_chip m_irq_chip mn10300_cpu_pic_level xtensa_irq_chip iop13xx_msi_chip msi_irq Because these irq_chips mask interrupts in 'disable' hook. Thus, your suspend_device_irqs() function disables all IRQs at the hardware level on all architectures which use irq_chips listed above in suspend state. Is this really what you wanted? If interrupt can wake up the system from suspend in some architectures and if disable_irq_wake is not supported in these architectures, I wonder if suspend_device_irqs() don't allow waking up by interrupt. Regards, Kyuwon