From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752207AbaG1Wnc (ORCPT ); Mon, 28 Jul 2014 18:43:32 -0400 Received: from v094114.home.net.pl ([79.96.170.134]:50581 "HELO v094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751502AbaG1Wn3 (ORCPT ); Mon, 28 Jul 2014 18:43:29 -0400 From: "Rafael J. Wysocki" To: Thomas Gleixner Cc: Peter Zijlstra , linux-kernel@vger.kernel.org, Linux PM list Subject: Re: [RFC][PATCH] irq: Rework IRQF_NO_SUSPENDED Date: Tue, 29 Jul 2014 01:01:59 +0200 Message-ID: <1629826.p5Zlf8Riij@vostro.rjw.lan> User-Agent: KMail/4.11.5 (Linux/3.16.0-rc5+; KDE/4.11.5; x86_64; ; ) In-Reply-To: <2706544.qjOZ3fREQ9@vostro.rjw.lan> References: <20140724212620.GO3935@laptop> <2706544.qjOZ3fREQ9@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 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. Rafael