Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752428AbZIYHUn (ORCPT ); Fri, 25 Sep 2009 03:20:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751166AbZIYHUm (ORCPT ); Fri, 25 Sep 2009 03:20:42 -0400 Received: from an-out-0708.google.com ([209.85.132.243]:55444 "EHLO an-out-0708.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750769AbZIYHUl (ORCPT ); Fri, 25 Sep 2009 03:20:41 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:reply-to:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type; b=iyT0SZv5WcUCPWQBVOFvIJ8S4gY2L3OEbbi1WxFVkVsQdJM2oOqwWVvAgGgalCKWmb L/fKdVufcYCHpX1iMUTR2j92XOxUa1iZR/pny1hJPIhWpkYQBWjmckzxqxR+bn8nmoge PfibN2fnrL/WWW855afQBxgDzWm+68ksXBcuc= MIME-Version: 1.0 Reply-To: balbir@in.ibm.com In-Reply-To: <20090924142228.5a2ddf59@infradead.org> References: <20090922112526.GA7788@linux.vnet.ibm.com> <20090924051238.GA5963@linux.vnet.ibm.com> <20090924142228.5a2ddf59@infradead.org> Date: Fri, 25 Sep 2009 12:50:44 +0530 X-Google-Sender-Auth: 96607bfb917e96cd Message-ID: <661de9470909250020u711031djfbf30f41e06d60bf@mail.gmail.com> Subject: Re: [v6 PATCH 0/7]: cpuidle/x86/POWER: Cleanup idle power management code in x86, cleanup drivers/cpuidle/cpuidle.c and introduce cpuidle to POWER. From: Balbir Singh To: Arjan van de Ven Cc: arun@linux.vnet.ibm.com, Len Brown , Peter Zijlstra , Joel Schopp , Benjamin Herrenschmidt , Paul Mackerras , Ingo Molnar , Vaidyanathan Srinivasan , Dipankar Sarma , Gautham R Shenoy , Shaohua Li , Venkatesh Pallipadi , linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-acpi@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1510 Lines: 39 On Thu, Sep 24, 2009 at 5:52 PM, Arjan van de Ven wrote: > On Thu, 24 Sep 2009 10:42:41 +0530 > Arun R Bharadwaj wrote: > >> * Arun R Bharadwaj [2009-09-22 16:55:27]: >> >> Hi Len, (or other acpi folks), >> >> I had a question regarding ACPI-cpuidle interaction in the current >> implementation. >> >> Currently, every cpu (i.e. acpi_processor) registers to cpuidle as >> a cpuidle_device. So every cpu has to go through the process of >> setting up the idle states and then registering as a cpuidle device. >> >> What exactly is the reason behind this? >> > > technically a BIOS can opt to give you C states via ACPI on some cpus, > but not on others. > > in practice when this happens it tends to be a bug.. but it's > technically a valid configuration In this day and age of flashable BIOS with recovery BIOS built in, can't we just print out a big far warning, asking users of such systems to go back to their vendors and ask for updates or find the updates and apply them? Does the OS have to do the heavy lifting and allow users to live with buggy BIOS's. When you say it is a technically valid configuration, you mean that the ACPI spec allows for such inconsistency? Balbir Singh -- 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/