ACPI Testing

Satish Balay balay at fastmail.fm
Sat Jun 19 15:54:31 UTC 2004



On Sat, 19 Jun 2004, D. D. Brierton wrote:
>
> Do I actually want both running at the same time? I assume that for
> testing purposes I should disable APM, but I'd like to hear from someone
> who knows what he's talking about.

I believe it doesn't matter if both apm & acpi daemons run
simultaneously.  But only one of features in enabled in the kernel at
boot time - so only one works - (and the other daemon just doesn't
matter)

the kernel boot option to switch is to apm is 'acpi=off'

> 3. Does FC2 automatically go into "laptop" mode when I pull out the
> power cord, or do I have to do something manually? (I can't find now
> where I read about this, but I believe "laptop" mode is something new in
> the 2.6 kernel which preserves battery life by slowing the CPU speed and
> reducing disk activity.)

laptop mode is introduced in FC1 (2.4 kernel) - and with APM it
switches on automatically when AC is unplugged. This primarily affects
disk activity (and not CPU speed) 'cat /proc/sys/vm/laptop_mode'

Wrt cpuscaling - this is also present in both FC1 and FC2. On FC1 I
load the module speedstep-centrino (for my P-M) and use copudynd
userspace daemon - with APM.

On FC2 - the relavant modules are built into the kernel - and they
load automatically. The default userspace daemon is 'cpuspeed' - and
this works with both APM & ACPI.

------------------

Hardware: IBM Thinkpad T40 : 1.6 P-M with Radeon 9000 mobile,
intel-e1000 network and IBM a/b wireless (atheros chipset) (haven't
checked bluetooth/irda/modem)

Currently I'm primarily using FC1 & APM. With Power Managemnt - I
primarily care about reliable suspend/resume - and don't care about
hybernation.  FC2 with APM works just as well as FC1.

With FC2 & ACPI - the issues I had:

- e1000 driver doesn't work after suspend/resume
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=121906

- there was a brief stint were suspend didn't work with USB (I haven't
checked this with 435 kernel)
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=124337

- Battery life might be poor with ACPI compared to APM. I haven't
really timed it though. Well one indication of this is - with ACPI
suspend - the CDROM drive light continues to blink (draining power),
this doesn't happen with APM.

- There could have been some issues with madwifi driver and acpi - but
from reading madwifi list - this issue might be fixed with one of the
new patches in cvs.

---------------------

One of the reasons I wanted to try ACPI - is the extra monitoring
features in it (for eg: get CPU temperature displayed by gkrellm). But
its not crucial as long as APM continues to work.

Satish





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