Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756687AbZFVNsh (ORCPT ); Mon, 22 Jun 2009 09:48:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751607AbZFVNsa (ORCPT ); Mon, 22 Jun 2009 09:48:30 -0400 Received: from casper.infradead.org ([85.118.1.10]:40080 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751337AbZFVNs3 convert rfc822-to-8bit (ORCPT ); Mon, 22 Jun 2009 09:48:29 -0400 Date: Mon, 22 Jun 2009 06:49:15 -0700 From: Arjan van de Ven To: Magnus Damm Cc: Alan Stern , "Rafael J. Wysocki" , Greg KH , LKML , ACPI Devel Maling List , Linux-pm mailing list , Ingo Molnar Subject: Re: [linux-pm] [patch update 2 fix] PM: Introduce core framework for run-time PM of I/O devices Message-ID: <20090622064915.741154a7@infradead.org> In-Reply-To: References: <20090621234324.06fda564@infradead.org> Organization: Intel X-Mailer: Claws Mail 3.7.0 (GTK+ 2.14.7; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1678 Lines: 42 On Mon, 22 Jun 2009 16:27:29 +0900 Magnus Damm wrote: > On Mon, Jun 22, 2009 at 3:43 PM, Arjan van de > Ven wrote: > > On Mon, 22 Jun 2009 15:20:43 +0900 > > Magnus Damm wrote: > > > >> On Sat, Jun 20, 2009 at 11:30 PM, Alan > >> Stern wrote: > >> > Some more thoughts... > >> > > >> > Magnus, you might have some insights here.  It occurred to me > >> > that some devices can switch power levels very quickly, and the > >> > drivers might therefore want the runtime suspend and resume > >> > methods to be called as soon as possible, even in interrupt > >> > context. > >> > >> I'd like to call pm_request_suspend() from interrupt context. I > >> don't > > > > there are some really strong reasons to at least be able to call the > > resume function from an interrupt handler.... shared interrupts are > > one of them. > > I suppose you mean that you need to resume the hardware device before > you can check if it has a pending interrupt source? If so then you > also mean that suspended hardware devices may generate interrupts, no? yes and no. For the shared interrupt case.. no. but yes for the hw I have in mind (and on my desk ;-) that can happen as well from the device itself. -- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/