From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754768AbaG3Vh1 (ORCPT ); Wed, 30 Jul 2014 17:37:27 -0400 Received: from v094114.home.net.pl ([79.96.170.134]:52874 "HELO v094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751539AbaG3Vgd (ORCPT ); Wed, 30 Jul 2014 17:36:33 -0400 From: "Rafael J. Wysocki" To: Thomas Gleixner , Peter Zijlstra Cc: linux-kernel@vger.kernel.org, Linux PM list , Dmitry Torokhov Subject: [PATCH 0/3] irq / PM: wakeup interrupt interface for drivers (was: Re: [RFC][PATCH] irq: Rework IRQF_NO_SUSPENDED) Date: Wed, 30 Jul 2014 23:46:59 +0200 Message-ID: <8151374.tpuvaHv3nd@vostro.rjw.lan> User-Agent: KMail/4.11.5 (Linux/3.16.0-rc5+; KDE/4.11.5; x86_64; ; ) In-Reply-To: <3042738.6Ohp3GcNCj@vostro.rjw.lan> References: <20140724212620.GO3935@laptop> <3042738.6Ohp3GcNCj@vostro.rjw.lan> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tuesday, July 29, 2014 03:33:23 PM Rafael J. Wysocki wrote: > On Tuesday, July 29, 2014 02:46:41 PM Thomas Gleixner wrote: > > On Tue, 29 Jul 2014, Rafael J. Wysocki wrote: > > > > > On Monday, July 28, 2014 11:53:15 PM Rafael J. Wysocki wrote: > > > > On Monday, July 28, 2014 02:33:41 PM Thomas Gleixner wrote: > > > > > On Mon, 28 Jul 2014, Peter Zijlstra wrote: > > > > > > On Sat, Jul 26, 2014 at 01:49:17PM +0200, Rafael J. Wysocki wrote: > > > > > > [cut] > > > > > > > > So we are not going to make everything a single stupid flag and limit > > > > > the usability of existing code. We rather go and try to remove the > > > > > stupid flag before it becomes more wide spread. > > > > > > > > > > And we cannot treat the wakeup thing the same way as the > > > > > IRQF_NO_SUSPEND flag, because there is hardware where the irq line > > > > > must be disabled at the normal (non suspend) interrupt controller, and > > > > > the wake mechanism tells the PM microcontroller to monitor the > > > > > interrupt line and kick the machine back to life. > > > > > > > > > > So we need to very carefully look at all the existing cases instead of > > > > > yelling crap and inflicting x86 specific horror on everyone. I said on > > > > > friday, that I need to look at ALL use cases first and I meant it. > > > > > > > > Regardless of the use case, I don't think it is necessary to manipulate > > > > the interrupt controller settings before the syscore_suspend stage, because > > > > if an interrupt happens earlier, we need to handle it pretty much in a normal > > > > way, unless it has been suspended. > > > > > > > > So I'd argue for not using anything like enable_irq_wake() that goes all > > > > the way to the hardware in drivers. Instead, we could allow drivers to > > > > mark interrupts as "set this up for system wakeup" and really do the setup > > > > right before putting the platform into the final "suspended" state. And that > > > > is totally independend of the IRQF_NO_SUSPEND thing. > > > > > > In addition to that we need the interrupt handler of the driver that requested > > > the irq to be set up for system wakeup to be invoked after suspend_device_irqs() > > > in case there are interrupts that should abort the suspend transition or we > > > can lose a wakeup event. So whatever interface we decide to use it has to > > > affect suspend/resume_device_irqs() pretty much in the same way as the > > > IRQF_NO_SUSPEND flag. > > > > Right, that's a different issue. We probably want that even for the > > existing irq_wake() users. > > I agree. > > There's one more thing to consider here. Going forward we'll want to avoid > touching runtime-suspended devices during system suspend. Then, system wakeup > devices will need to mark their IRQs for system wakeup at the runtime suspend > time and I'm not sure if that's the right time for calling enable_irq_wake(). Taking all of the above into consideration I prepared a prototype that will follow. Patch [1/3] is the actual prototype of the core changes, patch [2/3] uses that to implement suspend-to-idle wakeup for PME and patch [3/3] illustrates how an existing user of enable_irq_wake() can be modified to use the new stuff. All is on top of https://patchwork.kernel.org/patch/4643871/ which should apply on top of -tip (if I'm not mistaken). I've tested patches [1-2/3] with PME on my MSI Wind. Comments welcome. Rafael