From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Rutland Subject: Re: [PATCH v2 5/6] watchdog: at91sam9: request the irq with IRQF_NO_SUSPEND Date: Thu, 5 Mar 2015 10:57:29 +0000 Message-ID: <20150305105729.GB13617@leverpostej> References: <1425287898-15093-1-git-send-email-boris.brezillon@free-electrons.com> <1425287898-15093-6-git-send-email-boris.brezillon@free-electrons.com> <20150304183809.GD22156@leverpostej> <14143668.0aRkeVrc3Q@vostro.rjw.lan> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <14143668.0aRkeVrc3Q-sKB8Sp2ER+y1GS7QM15AGw@public.gmane.org> Sender: linux-watchdog-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: "Rafael J. Wysocki" Cc: Boris Brezillon , Thomas Gleixner , Jason Cooper , Peter Zijlstra , Len Brown , Pavel Machek , "linux-pm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Wim Van Sebroeck , "linux-watchdog-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Alessandro Zummo , "rtc-linux-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org" , Greg Kroah-Hartman , Jiri Slaby , "linux-serial-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Mike Turquette , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Nicolas Ferre , Jean-Christophe Plagniol-Villard , Alexandre Belloni List-Id: linux-serial@vger.kernel.org [...] > > > err = request_irq(wdt->irq, wdt_interrupt, > > > - IRQF_SHARED | IRQF_IRQPOLL, > > > + IRQF_SHARED | IRQF_IRQPOLL | > > > + IRQF_NO_SUSPEND, > > > > I'm a little confused by this. What happens if the watchdog fires when > > we're actually in the suspended state (when IRQF_NO_SUSPEND interrupts > > aren't guaranteed to be delivered). > > Why wouldn't they be delivered? > > If that's suspend-to-idle, we'll handle them normally. If that's full suspend, > they may not be handled at the last stage (when we run on one CPU with interrupts > off), but that was the case before the wakeup interrupts rework already and I'd > expect it to be taken into account somehow in the existing code (or if it isn't > taken into account, we have a bug, but it is not related to this series). There's no enable_irq_wake(wdt->irq), and I was under the impression this is for full suspend. I agree that if problematic, it's an existing bug. Given Boris's comments in the other thread this may just a minor semantic issue w.r.t. IRQF_NO_SUSPEND vs IRQF_COND_SUSPEND. Thanks, Mark. -- To unsubscribe from this list: send the line "unsubscribe linux-watchdog" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html