From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753429AbZEYHDL (ORCPT ); Mon, 25 May 2009 03:03:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752023AbZEYHC6 (ORCPT ); Mon, 25 May 2009 03:02:58 -0400 Received: from mailout4.samsung.com ([203.254.224.34]:51922 "EHLO mailout4.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752022AbZEYHC5 (ORCPT ); Mon, 25 May 2009 03:02:57 -0400 Date: Mon, 25 May 2009 16:02:47 +0900 From: Kim Kyuwon Subject: Re: [PATCH] PM: suspend_device_irqs(): don't disable wakeup IRQs In-reply-to: <200905232214.57186.rjw@sisk.pl> To: "Rafael J. Wysocki" Cc: Kim Kyuwon , Andrew Morton , linux-pm@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Ingo Molnar , Kyungmin Park , Linus Torvalds , Kevin Hilman Message-id: <4A1A4297.50809@samsung.com> MIME-version: 1.0 Content-type: text/plain; format=flowed; charset=ISO-8859-1 Content-transfer-encoding: 7BIT User-Agent: Thunderbird 2.0.0.21 (Windows/20090302) References: <1241483224-7113-1-git-send-email-khilman@deeprootsystems.com> <200905230029.18279.rjw@sisk.pl> <4d34a0a70905221603g785f5b78h330249ff258dbfdd@mail.gmail.com> <200905232214.57186.rjw@sisk.pl> X-OriginalArrivalTime: 25 May 2009 07:02:48.0237 (UTC) FILETIME=[CFC905D0:01C9DD06] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Rafael J. Wysocki wrote: > On Saturday 23 May 2009, Kim Kyuwon wrote: >> On Sat, May 23, 2009 at 7:29 AM, Rafael J. Wysocki wrote: >>> On Saturday 23 May 2009, Kim Kyuwon wrote: > [--snip--] >>>> You changed the really important part of Linux, which may affect most >>>> processor architectures. I think you should be careful. If some of >>>> architectures can't take care of it (they can implement >>>> disable_irq_wake correctly in H/W level, will you revert your changes? >>> No, the changes are not going to be reverted. In fact things should have been >>> done like this already much earlier. >>> >>> Now, do you have any particular example of a problem related to these changes >>> or is it only a theoretical issue? >> I'd CCing you when I'm sending a mail for this particular example of a example. >> http://markmail.org/thread/fvt7d62arofon5xx > > Well, as I said above, reverting the changes that introduced > [suspend|resume]_device_irqs() is not an option, becuase it was the only sane > way to achieve the goal they were added for. So, we need to fix the wake-up > problem on your platform with the assumption that > [suspend|resume]_device_irqs() are going to stay. > > For starters, would it be possible to teach the 'disable' hook of your > platform's interrupt controller not to mask the IRQs that have both > IRQ_WAKEUP and IRQ_SUSPENDED set? That apparently would work around the > wake-up interrupts problem. Thank you for considering this issue and spending your time. In order to make your idea work, we need to add a dummy 'set_wake' hook which returns always zero. Anyway, IMO, I think your idea is good to work around this problem. But Kevin Hilman(OMAP PM Maintainer) would make final decision. Buy the way, how can you handle the problem that a few interrupt are discarded in a small window? I can be sure they are discarded, because I have debugged defects which generate in sleep/resume state hundreds of times on ARM Processors(PXA310, S3C6410, OMAP3430). Wake-up interrupts are generated as soon as arch_suspend_enable_irqs() invoked. Regards, Kyuwon