misc/102783: hw.acpi has thermal controls backwards when external power connected at bootup

[Jason Boisvert]

>Number:         102783
>Category:       misc
>Synopsis:       hw.acpi has thermal controls backwards when external power connected at bootup
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Sat Sep 02 13:00:36 GMT 2006
>Closed-Date:
>Last-Modified:
>Originator:     Jason Boisvert
>Release:        6.1-Release
>Organization:
University of Colorado - Boulder
>Environment:
[boisvert at kailash] ~ $ uname -a
FreeBSD kailash 6.1-RELEASE FreeBSD 6.1-RELEASE #8: Thu Jun 15 14:12:03 MDT 2006     root at kailash:/usr/obj/usr/src/sys/KAILASH  i386

>Description:
I have a 2004 model gateway 450 laptop with intel centrino.

When I start the computer with the external power connected, I get a bitflip for acpi regarding power source vis-a-vis thermal control.

Here are the two main configurations seen from the output of 
'sysctl -a | grep thermal':

Normal state plugged in:

hw.acpi.thermal.min_runtime: 0
hw.acpi.thermal.polling_rate: 10
hw.acpi.thermal.tz0.temperature: 56.0C
hw.acpi.thermal.tz0.active: 1
hw.acpi.thermal.tz0.passive_cooling: 1
hw.acpi.thermal.tz0.thermal_flags: 0
hw.acpi.thermal.tz0._PSV: 92.0C
hw.acpi.thermal.tz0._HOT: -1
hw.acpi.thermal.tz0._CRT: 100.0C
hw.acpi.thermal.tz0._ACx: 60.0C 55.0C -1 -1 -1 -1 -1 -1 -1 -1

Normal state with battery:

hw.acpi.thermal.min_runtime: 0
hw.acpi.thermal.polling_rate: 10
hw.acpi.thermal.tz0.temperature: 57.0C
hw.acpi.thermal.tz0.active: -1
hw.acpi.thermal.tz0.passive_cooling: 1
hw.acpi.thermal.tz0.thermal_flags: 0
hw.acpi.thermal.tz0._PSV: 92.0C
hw.acpi.thermal.tz0._HOT: -1
hw.acpi.thermal.tz0._CRT: 100.0C
hw.acpi.thermal.tz0._ACx: 92.0C 87.0C -1 -1 -1 -1 -1 -1 -1 -1

Note that in the last line (_ACx) the values changed from 60.0C 55.0C to 92.0C 87.0C. This is what should be happening as far as I can tell. Having the higher temps means the fan turns on later with the battery.

The problem is these configurations are reversed when the computer is booted with the external power connected. I.e., if I start the computer plugged in and then unplug it, it will run the cooler version of thermal control and use more battery. Also, using this backwards configuration it obviously can get hotter than it should while plugged in.

Moreover, this is a recent problem that started -- I think -- with 6.1-Release. It may have started with 6.0-Release, but I know it wasn't happening for the prerelease of 6.0.

Thanks.
Jason Boisvert


>How-To-Repeat:
Start the computer with the external power source connected.
>Fix:
It seems like the system assumes (or inaccurately assesses) from the start that the battery is the power source regardless of if this is true. It shouldn't be hard to change that behavior (I hope).
>Release-Note:
>Audit-Trail:
>Unformatted: