From owner-freebsd-acpi@FreeBSD.ORG Fri Nov 15 15:44:09 2013 Return-Path: Delivered-To: freebsd-acpi@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 2E8EB45D; Fri, 15 Nov 2013 15:44:09 +0000 (UTC) Received: from bigwig.baldwin.cx (bigwig.baldwin.cx [IPv6:2001:470:1f11:75::1]) (using TLSv1 with cipher ADH-CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id 09D9C21B0; Fri, 15 Nov 2013 15:44:09 +0000 (UTC) Received: from jhbbsd.localnet (unknown [209.249.190.124]) by bigwig.baldwin.cx (Postfix) with ESMTPSA id B7D61B91E; Fri, 15 Nov 2013 10:44:06 -0500 (EST) From: John Baldwin To: freebsd-acpi@freebsd.org Subject: Re: P-state setting suddenly disappeared, what gives? Date: Fri, 15 Nov 2013 09:17:12 -0500 User-Agent: KMail/1.13.5 (FreeBSD/8.4-CBSD-20130906; KDE/4.5.5; amd64; ; ) References: <52855927.9010103@FreeBSD.org> In-Reply-To: <52855927.9010103@FreeBSD.org> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201311150917.12998.jhb@freebsd.org> X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.2.7 (bigwig.baldwin.cx); Fri, 15 Nov 2013 10:44:06 -0500 (EST) Cc: njl@freebsd.org X-BeenThere: freebsd-acpi@freebsd.org X-Mailman-Version: 2.1.16 Precedence: list List-Id: ACPI and power management development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 15 Nov 2013 15:44:09 -0000 On Thursday, November 14, 2013 6:13:43 pm Jung-uk Kim wrote: > On 2013-11-14 17:41:44 -0500, Adrian Chadd wrote: > > Hi all, > > > > I have this Lenovo T400 that I've been doing FreeBSD development on > > for a while. > > > > It has a P8700 in it: > > > > CPU: Intel(R) Core(TM)2 Duo CPU P8700 @ 2.53GHz (2527.07-MHz > > 686-class CPU) > > > > Now, up until yesterday, ACPI exported the required twiddles to > > enter various different P-states. > > > > However, as of sometime yesterday, it stopped being able to do so. > > > > sysctl dev.cpu.0.freq returns nothing. Setting it to something > > retuns "device not configured." The frequency list (ie, the P-state > > list) is still fine. > > > > I had to load cpufreq.ko to get the enhanced speedstep stuff to > > show up, but (a) it doesn't support this CPU (and it seems to have > > stopped growing EST bits after Pentium M CPUs..) and (b) setting > > the frequency using it versus P-state settings doesn't save as much > > power. > > > > I'd like to try and debug why the heck this is. > > > > The laptop still works fine, things are just not as "nice" as they > > once were. > > > > Any ideas? Any suggestions on where to start debugging this? > > SSDT tables for Intel processors are usually dynamic and often times > additional tables are loaded per _OSC or _PDC. [1] Basically, we > advertise our capabilities from sys/dev/acpica/acpi_cpu.c, depending > on loaded device drivers. Unfortunately, some times it is too late > and some SSDTs are not properly loaded. Also, warm booting from other > OSes to FreeBSD may cause similar problems. > > To debug the problem, you need to dump DSDT and SSDTs and try to > understand _OSC (or _PDC), _PCT and _PSS for your system. Also, the reason that est.c doesn't hardcode tables for modern CPUs is that on modern systems the tables are provided by ACPI via the acpi_perf(4) driver. -- John Baldwin