From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932079AbWELNw6 (ORCPT ); Fri, 12 May 2006 09:52:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932078AbWELNw6 (ORCPT ); Fri, 12 May 2006 09:52:58 -0400 Received: from smtp106.sbc.mail.mud.yahoo.com ([68.142.198.205]:52598 "HELO smtp106.sbc.mail.mud.yahoo.com") by vger.kernel.org with SMTP id S932079AbWELNw6 (ORCPT ); Fri, 12 May 2006 09:52:58 -0400 From: David Brownell To: linux-pm@lists.osdl.org Subject: Re: [linux-pm] Re: [PATCH/rfc] schedule /sys/device/.../power for removal Date: Fri, 12 May 2006 06:52:53 -0700 User-Agent: KMail/1.7.1 Cc: Andrew Morton , Pavel Machek , linux-kernel@vger.kernel.org References: <20060512100544.GA29010@elf.ucw.cz> <20060512031151.76a9d226.akpm@osdl.org> In-Reply-To: <20060512031151.76a9d226.akpm@osdl.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200605120652.55658.david-b@pacbell.net> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Friday 12 May 2006 3:11 am, Andrew Morton wrote: > > What will be impacted by this? Driver suspend/resume testing ... impact is strongly negative. Without this interface, there is NO way to test individual drivers for correct handling of suspend/resume calls; the only way to test drivers is to suspend/resume the whole system, along with all other drivers in the system. Which means that ALL the drivers must work sanely before tests for any one of them can succeed ... a losing model when you're testing PM on new platforms. Which IMO makes removing this a Bad Thing. It needs to have some kind of replacement in place before the "magic numbers" go away. (The magic numbers are bad, and should go away -- yes. Nobody has really shown that userspace needs this mechanism for any purpose other than driver testing. Userspace device-specific power management tools would need knowledge that's not yet exposed though sysfs.) I think both Patrick Mochel and Alan Stern have sent patches at various times to let individual drivers provide a list of named states they support, In some cases (like PCI) those lists could be delegated to bus-specific code.