2005-04-29 23:59:21

by Joshua Kwan

[permalink] [raw]
Subject: Problems with Centrino frequency modulation

Hello!

I'm running 2.6.11.7 on an IBM Thinkpad T42. APM is working out very
nicely in everything except clock modulation, which seems to require
ACPI before speedstep-centrino will see it. p4-clockmod is able to
wrangle the CPU, but it warns that I should really be using
speedstep-centrino as p4-clockmod can't change the CPU voltage.

My CPU is family 6 / model 13 / stepping 6 (CPU_DOTHAN_B0 in
speedstep-centrino.c.) Is there a way to get speedstep-centrino working
without having to use the wretched ACPI (which, among other things,
prevents -- or at least makes it a large magnitude harder to -- sleep.
If I do echo 3 > /proc/acpi/sleep or echo mem > /sys/power/state, it
sleeps correctly, but will wake up with a blank screen or a completely
white one. [Observant readers will notice this is exactly what I
reported with my last laptop and I'm disappointed to notice that the
problem is not restricted to that POS.]) Therefore, I really, really
don't want to use ACPI.

Any suggestions?

Thanks.

--
Joshua Kwan


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2005-04-30 00:55:22

by Kevin Fenzi

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Subject: Re: Problems with Centrino frequency modulation

>>>>> "Joshua" == Joshua Kwan <[email protected]> writes:

Joshua> Hello! I'm running 2.6.11.7 on an IBM Thinkpad T42. APM is
Joshua> working out very nicely in everything except clock modulation,
Joshua> which seems to require ACPI before speedstep-centrino will see
Joshua> it. p4-clockmod is able to wrangle the CPU, but it warns that
Joshua> I should really be using speedstep-centrino as p4-clockmod
Joshua> can't change the CPU voltage.

Joshua> My CPU is family 6 / model 13 / stepping 6 (CPU_DOTHAN_B0 in
Joshua> speedstep-centrino.c.) Is there a way to get
Joshua> speedstep-centrino working without having to use the wretched
Joshua> ACPI (which, among other things, prevents -- or at least makes
Joshua> it a large magnitude harder to -- sleep. If I do echo 3 >
Joshua> /proc/acpi/sleep or echo mem > /sys/power/state, it sleeps
Joshua> correctly, but will wake up with a blank screen or a
Joshua> completely white one. [Observant readers will notice this is
Joshua> exactly what I reported with my last laptop and I'm
Joshua> disappointed to notice that the problem is not restricted to
Joshua> that POS.]) Therefore, I really, really don't want to use
Joshua> ACPI.

Not that you want to hear it, but I have a T42p (that I just got a few
weeks ago) and it can do S3 suspend/resume just fine.

There are 3 things you need to do:

boot with: "acpi_sleep=s3_bios"

rmmod all the usb modules before suspending.

do not use the binary only ati drivers.

I use the hibernate script from the suspend2 project:
http://suspend2.net/
set to do S3 instead of suspend2, which also unloads blacklisted
modules (Including the usb ones) and re-loads them on resume.

You might try that if you get a chance. ACPI has come a long way...

Joshua> Thanks.
Joshua> -- Joshua Kwan

kevin