Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758027AbZFOUCI (ORCPT ); Mon, 15 Jun 2009 16:02:08 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752124AbZFOUB4 (ORCPT ); Mon, 15 Jun 2009 16:01:56 -0400 Received: from ogre.sisk.pl ([217.79.144.158]:45639 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751259AbZFOUBz (ORCPT ); Mon, 15 Jun 2009 16:01:55 -0400 From: "Rafael J. Wysocki" To: Arjan van de Ven Subject: Re: [patch update] PM: Introduce core framework for run-time PM of I/O devices Date: Mon, 15 Jun 2009 22:02:30 +0200 User-Agent: KMail/1.11.2 (Linux/2.6.30-rjw; KDE/4.2.4; x86_64; ; ) Cc: Alan Stern , Oliver Neukum , Magnus Damm , linux-pm@lists.linux-foundation.org, ACPI Devel Maling List , Ingo Molnar , LKML , Greg KH References: <200906140023.36147.rjw@sisk.pl> <200906150057.32424.rjw@sisk.pl> <20090614161850.01435082@infradead.org> In-Reply-To: <20090614161850.01435082@infradead.org> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200906152202.32094.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2142 Lines: 49 On Monday 15 June 2009, Arjan van de Ven wrote: > On Mon, 15 Jun 2009 00:57:31 +0200 > "Rafael J. Wysocki" wrote: > > > On Sunday 14 June 2009, Rafael J. Wysocki wrote: > > > On Sunday 14 June 2009, Rafael J. Wysocki wrote: > > > > Hi, > > > > > > > > Below is the current version of my "run-time PM for I/O devices" > > > > patch. > > > > > > > > I've done my best to address the comments received during the > > > > recent discussions, but at the same time I've tried to make the > > > > patch only contain the most essential things. For this reason, > > > > for example, the sysfs interface is not there and it's going to > > > > be added in a separate patch. > > > > > > > > Please let me know if you want me to change anything in this > > > > patch or to add anything new to it. [Magnus, I remember you > > > > wanted something like ->runtime_wakeup() along with > > > > ->runtime_idle(), but I'm not sure it's really necessary. Please > > > > let me know if you have any particular usage scenario for it.] > > > > Appended is an update of the patch addressing the today's comments > > from Magnus. > > few comments from me > > 1) For the usecases for upcoming hw from Intel (where you really can't talk to the hw while it's in powersave mode); the locking needs to be > IRQ safe. Think of it like this: > Lets assume you get a (shared) interrupt from your device. In the handler you need to make 100% sure that > 1) you're not suspended at this point .. basically do a forced wakeup right there and then > 2) assure that you're not about to suspend Does it mean we need to use spin_[un]lock_irq[save|restore]() everywhere in the framework? > 2) You use jiffies in the API; I would suggest exposing milliseconds instead and internally convert to jiffies; > milliseconds tends to be a much more natural unit for this sort of thing OK Best, Rafael -- 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/