From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: Processor states and USB Date: Tue, 26 Nov 2002 14:59:34 +0100 Sender: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Message-ID: <20021126135934.GC1268@zaurus> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Errors-To: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Help: List-Post: List-Subscribe: , List-Unsubscribe: , List-Archive: To: Jan Rychter Cc: acpi-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: linux-acpi@vger.kernel.org Hi! > My CPU has the following states: > > C1: promotion[C2] demotion[--] latency[000] usage[00100920] > C2: promotion[C3] demotion[C1] latency[001] usage[06199483] > *C3: promotion[--] demotion[C2] latency[100] usage[12803374] > > Now, whenever the usb-uhci module is loaded, C3 never gets > used. C2 is the only state that my CPU is in. If I unload usb-uhci, the > machine starts using C3. > > Somebody explained to me that this is because the usb-uhci driver uses > DMA transfers to talk to the hardware and poll it for new devices. Is > there a patch available that changes this behavior? Anybody found any > solutions to this? UHCI is crap, and this will be hard to solve. You should have seen what it does with system performance in FSBR mode.... usb-devel is better place for this discussion... -- Pavel Written on sharp zaurus, because my Velo1 broke. If you have Velo you don't need... ------------------------------------------------------- This SF.net email is sponsored by: Get the new Palm Tungsten T handheld. Power & Color in a compact size! http://ads.sourceforge.net/cgi-bin/redirect.pl?palm0002en