From mboxrd@z Thu Jan 1 00:00:00 1970 From: Janosch Machowinski Subject: Re: _CST implementation Date: Mon, 18 Apr 2005 19:52:31 +0200 Message-ID: <1113846751.8914.4.camel@scotchmobil> References: <1113598244.8367.30.camel@scotchmobil> <20050418120744.GG2298@poupinou.org> <4263EDA2.4030106@suse.de> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4263EDA2.4030106-l3A5Bk7waGM@public.gmane.org> Sender: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: acpi-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: linux-acpi@vger.kernel.org On Mon, 2005-04-18 at 19:25 +0200, Thomas Renninger wrote: > Bruno Ducrot wrote: > > On Fri, Apr 15, 2005 at 10:50:44PM +0200, Janosch Machowinski wrote: > ... > > > >>Oh I almost forgot another question : > >>About the validation of the C states. At the moment it is tested if the > >>latency of C2 if under 100 and if C3 latency is under 1000 but the > >>ACPI-Spec says that "There is no latency restrictions" so why do you do > >>this ? (My notebook hat a C3 latency of 1001) > > > > Normally you are right, but unfortunately there are still some strange > > misread of the specification by bios writters in that regard. Therefore > > if for C3 the latency is 1001 even if given by _CST, we should disable > > it. > > > > My spec says (Revision 3.0, September 2, 2004): > The worst-case hardware latency for this state is declared in the FADT > (p. 257). > > And there they say (p. 98): > The worst-case hardware latency, in microseconds, to enter and > exit a C2 state. A value > 100 indicates the system does not > support a C2 state. > The worst-case hardware latency, in microseconds, to enter and > exit a C3 state. A value > 1000 indicates the system does not > support a C3 state. > > Thomas Hm this is somehow funny. So we could say, that latency values in the FADT are restricted, and latency values from _CST value are not restricted (p. 261). Janosch ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click