From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michael Guntsche Subject: Re: Processor C states and USB problem Date: Fri, 9 Jan 2004 19:24:42 +0100 Sender: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Message-ID: <20040109192442.5220dfe5.mike@it-loops.com> References: <571ACEFD467F7749BC50E0A98C17CDD8E84E6C@PDSMSX403.ccr.corp.intel.com> <1073640699.10144.14.camel@ltspc67.epfl.ch> <1073643322.10144.23.camel@ltspc67.epfl.ch> <20040109165421.6fc2483a.mike@it-loops.com> <20040109093553.31aa1c79.rddunlap@osdl.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20040109093553.31aa1c79.rddunlap-3NddpPZAyC0@public.gmane.org> Errors-To: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: "Randy.Dunlap" Cc: acpi-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: linux-acpi@vger.kernel.org On Fri, 9 Jan 2004 09:35:53 -0800 "Randy.Dunlap" wrote: > On Fri, 9 Jan 2004 16:54:21 +0100 Michael Guntsche > wrote: > > | On Fri, 09 Jan 2004 11:15:22 +0100 > | Diego SANTA CRUZ wrote: > | > | > On Fri, 2004-01-09 at 11:05, Petr Olivka wrote: > | > > in 2.4 kernel I have to unload all usb modules. Then power drop > | > > to C3 state. If I remember, only usbcore can be loaded (on my > | > > D600). > | > > > | > > | > But even booting with init=/bin/sh and without ever loading any > | > USB module I get permanent bus mastering activity. Any ideas? > | > | I see the same on my notebook with a 2.4 kernel. Sometimes it works, > | but most of the time there is Bus master acitivty. > | With 2.6 I only see that if I have a USB device plugged in (mouse) > | that gets polled. > > It seems like one of the early usb uhci host controller drivers (HCDs) > generated lots of bus master activity. Are you sure that uhci or > usb-uhci is not loaded (in the 2.4 problem case), even though no > USB device drivers are loaded? > Hmm, I did some tests and found out the following. With USB modules loaded bus master activity: ffffffff With USB modules removed, the number goes down, but the processor still stays in C2 most of the time. In 2.6 I only get "ffffffff" if the mouse is plugged otherwise the notebook spends more time in C3. Since I am using 2.6 nowadays (PREEMPT being one of the main reasons), this is not very important for me. On a side note. Do you have an idea why I no longer have performance management and the limit interface with 2.6? I don't use those two myself, I just noticed it while testing ACPI in 2.6. /proc/acpi/processor/CPU0/info: processor id: 0 acpi id: 0 bus mastering control: yes power management: yes throttling control: no performance management: no <-- yes on 2.4 limit interface: no <-- yes on 2.4 This is an Acer 800 notebook with a Pentium M processor. /Michael ------------------------------------------------------- This SF.net email is sponsored by: Perforce Software. Perforce is the Fast Software Configuration Management System offering advanced branching capabilities and atomic changes on 50+ platforms. Free Eval! http://www.perforce.com/perforce/loadprog.html