From mboxrd@z Thu Jan 1 00:00:00 1970 From: Janosch Machowinski Subject: Re: High pitched sound with 2.6.15-ck1 -- Update info Date: Mon, 30 Jan 2006 22:59:05 +0100 Message-ID: <43DE8C29.1030007@tzi.de> References: <200601280105.44804.gkanis@cems.umn.edu> <43DB511B.5020605@tzi.de> <200601301732.47677.gkanis@cems.umn.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from m1.informatik.uni-bremen.de ([134.102.201.18]:26844 "EHLO informatik.uni-bremen.de") by vger.kernel.org with ESMTP id S932276AbWA3V67 (ORCPT ); Mon, 30 Jan 2006 16:58:59 -0500 In-Reply-To: <200601301732.47677.gkanis@cems.umn.edu> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Vasileios Gkanis Cc: linux-acpi@vger.kernel.org Vasileios Gkanis schrieb: >>Jep, >>this happens because your power converters starts "singing". If >>you switch the C-State, you need a different amount of power. So if >>you have a kernel frequency of 1000 herz, your power converter has >>to adjust the amount of power 1000 times per second. And because >>of that it starts "singing". By the way, you can also modulate the sound >>by scaling your CPU frequency up or down. (Perhaps you could also write >>a programm, that can play some melody based on this phaenomenon ;-) ) >> >> Janosch > > > What you said is correct. But, do you know why this happens when I plug in the > USB-mouse and not when I plug in the USB-stick? I would guess that the mouse has a higher power consumption as the stick. Try to put in some other usb-devices, that needs a lot of power (one of this usb-harddrives without external AC for example) and test it ;-) Janosch