From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Fri, 28 Mar 2008 12:35:25 +0100 (CET) Received: from h155.mvista.com ([63.81.120.155]:1132 "EHLO imap.sh.mvista.com") by lappi.linux-mips.net with ESMTP id S528495AbYC1LfR (ORCPT ); Fri, 28 Mar 2008 12:35:17 +0100 Received: from [192.168.1.234] (unknown [10.150.0.9]) by imap.sh.mvista.com (Postfix) with ESMTP id 1E7FA3ECA; Fri, 28 Mar 2008 04:34:44 -0700 (PDT) Message-ID: <47ECD828.8090600@ru.mvista.com> Date: Fri, 28 Mar 2008 14:36:08 +0300 From: Sergei Shtylyov Organization: MontaVista Software Inc. User-Agent: Mozilla/5.0 (X11; U; Linux i686; rv:1.7.2) Gecko/20040803 X-Accept-Language: ru, en-us, en-gb MIME-Version: 1.0 To: Ralf Baechle Cc: linux-mips@linux-mips.org, Nico Coesel Subject: Re: FW: Alchemy power managment code. References: <19CA9E279FDA5246B7D7A1C91A4AF7F40EF804@dealogicserver.DEALogic.nl> <47E7B970.30105@ru.mvista.com> <47E7BB4B.3080507@ru.mvista.com> <20080327223134.GA26997@linux-mips.org> In-Reply-To: <20080327223134.GA26997@linux-mips.org> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 18689 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: sshtylyov@ru.mvista.com Precedence: bulk X-list: linux-mips Hello. Ralf Baechle wrote: >> > The TOY cpunter 0 clockevent driver is also need to be written for >>>the recent kernel as CP0 timer stops ticking after wait insn is executed >>>-- see arch/mips/au1000/common/time.c... >> And here's found another possible issue with Alchemy PM -- the CP0 >>counter counts at unpredictable frequency in idle state (after executing >>"wait"), so the MIPS clocksource will probably be unstable? > Correct - and cevt-r4k won't be usable either. I guess that means you > leave the user the choice between either these two or using wait. Not > nice but ... The Alchemy code doesn't even try to use CP0 counter when CONFIG_PM=y if you look into arch/mips/au1000/common/time.c... or at least it didn't before Atsushi removed do_fast_pm_gettimeoffset(). > Ralf WBR, Sergei