Date: Thu, 27 Nov 2008 23:31:50 +0100 From: martinko <gamato@users.sf.net> To: freebsd-mobile@freebsd.org Cc: freebsd-acpi@freebsd.org Subject: Re: Is the C3 possible with SMP? Message-ID: <ggn74m$8ui$1@ger.gmane.org> In-Reply-To: <20081122113015.B70117@sola.nimnet.asn.au> References: <20081121195714.CEE4B45010@ptavv.es.net> <20081122113015.B70117@sola.nimnet.asn.au>
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Ian Smith wrote: > On Fri, 21 Nov 2008, Kevin Oberman wrote: > > > From: martinko <gamato@users.sf.net> > > > [...] > > > > > > Hi, > > > > > > My laptop reports C1 state only: > > > > > > $ sysctl -a | grep cx_ > > > hw.acpi.cpu.cx_lowest: C1 > > > dev.cpu.0.cx_supported: C1/1 > > > dev.cpu.0.cx_lowest: C1 > > > dev.cpu.0.cx_usage: 100.00% > > > > > > But this is Pentium-M and I remember it could use C2 and C3 back with > > > 5.x kernel and I'm sure I had USB as I have now. > > > > > > Do you have any idea why I don't have C2/C3 states available anymore ?? > > > > Under 7-Stable, my Pentium-M system (ThinkPad T43) shows C1, C2, and > > C3. Of course, it's not an SMP. > > dev.cpu.0.cx_supported: C1/1 C2/1 C3/85 > > dev.cpu.0.cx_lowest: C1 > > dev.cpu.0.cx_usage: 100.00% 0.00% 0.00% > > > > cx_supported has nothing to do with the value of cx_lowest. It should > > simply be what the CPU reports back vi ACPI as to the C states supported > > on the platform. > > Well, except that cx_supported shows the possible values for cx_lowest; > ie you can only select a value for cx_lowest that's in cx_supported .. > so it does seem odd that martinko's cx_supported has been limited to C1? > > Whether the system ever actually uses the cx_lowest value you select, > other than C1, is another matter of course. My T23 (P3-M, 7.0-R) allows > selection of C3, but only ever uses it if the machine was booted up on > battery(!) but that might be a BIOS/EC bug that upgrading these may fix. > > cheers, Ian > Well, booting with or without battery does make a difference, strangely: $ sysctl dev.cpu dev.cpu.0.%desc: ACPI CPU dev.cpu.0.%driver: cpu dev.cpu.0.%location: handle=\_PR_.CPU1 dev.cpu.0.%pnpinfo: _HID=none _UID=0 dev.cpu.0.%parent: acpi0 dev.cpu.0.freq: 525 dev.cpu.0.freq_levels: 2000/-1 1800/-1 1600/-1 1400/-1 1225/-1 1200/-1 1050/-1 1 000/-1 875/-1 800/-1 700/-1 600/-1 525/-1 450/-1 375/-1 300/-1 225/-1 150/-1 75/ -1 dev.cpu.0.cx_supported: C1/1 C2/1 C3/2 dev.cpu.0.cx_lowest: C3 dev.cpu.0.cx_usage: 100.00% 0.00% 0.00% This was suggested to me by Henry Hu: Henry Hu wrote: > You may try to boot with battery. > If I boot with AC, there are only C1 and C2. But if I boot with > battery, there is C3. > I found that the line to recheck cx states has been commented in the > source code. So cx states keep the same since system startup. > > Cheers, > > Henry Cx states other than C1 are never used, unfortunately. Both C2 and C3 were used back with 5.something (I started with 5.3). I guess USB might be the culprit here. Anyway, it behaves strangely, at best. :( Cheers, Martin PS: Also, AFAIR C3 was not 2 but something like 100 back in times of 5.x when it worked on this laptop correctly.
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