From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932920AbXBKXkL (ORCPT ); Sun, 11 Feb 2007 18:40:11 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932922AbXBKXkL (ORCPT ); Sun, 11 Feb 2007 18:40:11 -0500 Received: from nigel.suspend2.net ([203.171.70.205]:54423 "EHLO nigel.suspend2.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932920AbXBKXkJ (ORCPT ); Sun, 11 Feb 2007 18:40:09 -0500 Subject: Re: NAK new drivers without proper power management? From: Nigel Cunningham Reply-To: nigel@nigel.suspend2.net To: "Rafael J. Wysocki" Cc: Robert Hancock , linux-kernel , Pavel Machek In-Reply-To: <200702120029.23657.rjw@sisk.pl> References: <200702110144.17783.rjw@sisk.pl> <1171233655.4493.78.camel@nigel.suspend2.net> <200702120029.23657.rjw@sisk.pl> Content-Type: text/plain Date: Mon, 12 Feb 2007 10:40:08 +1100 Message-Id: <1171237208.4493.139.camel@nigel.suspend2.net> Mime-Version: 1.0 X-Mailer: Evolution 2.8.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi. On Mon, 2007-02-12 at 00:29 +0100, Rafael J. Wysocki wrote: > > On Sun, 2007-02-11 at 01:44 +0100, Rafael J. Wysocki wrote: > > > > Well, it's probably more acceptable than silently doing nothing and the > > > > device failing or locking up the machine on resume, but I couldn't agree > > > > more that it's not what we want to be encouraging. Perfect may be the > > > > enemy of the good, but "works except no power management" is hardly what > > > > I would call good these days, more like pretty sloppy.. > > > > > > I think there are situations in which it can be justified, like: > > > - The driver is not entirely finished, but we want to merge it early, because > > > of many potential users, > > > - The driver has only a few users who aren't interested in the suspend/resume > > > functionality, > > > > How do you determine that? How many users have to want suspend/resume > > functionality before you say "Ok. It has to be done now"? > > That depends on what the driver author tells us. If he says there's only one > such device in the world and it needs a Linux drivers, but the system in > question will never be suspended, that will be fine, I think. There are such > cases already and I see no reason why there won't be any more in the future. > > > > - The device is undocumented and we don't know how to make it handle the > > > suspend/resume (we may learn that in the future or not). > > > > If we know how to initialise/cleanup, we know a good portion of what is > > needed for suspend/resume. Sure, for some video chipsets, you need more > > (you need to know how to reprogram the whole thing after S3), but > > they're the exception. Yes, there are other cases. But on the whole, > > we're not talking about esoteric knowledge. > > No, in general this is not _that_ simple. Please browse the archives of > bcm43xx-dev, for example. Yeah. The problems of not having documentation + having to reassociate and so on. > While I agree that the support for suspend and resume _is_ generally important, > I also admit that there are situations in which it doesn't matter and there are > many people who won't care a whit for it. Ok, but that's the exception, right? Not the rule? So in those cases, an exception is made. Regards, Nigel