ACPI question

jets0n · 11-13-2006, 02:04 PM

I hope this won't sound like a stupid question, but i'm confused. I'm running slackware 11 on my laptop, Toshiba M100 (Intel Core Duo, 1.67 GHz with Phoenix BIOS) and i seem to be having problems with ACPI. ACPI sems to work on my machine (the fan seems to be working, power profiles and speedstep are also working), but when i try to cat /proc/acpi/event or start acpid i get the following message -
"cannot read /proc/acpi/event. Device or resource busy".
I consider this to be a problem, as i have no thermal or fan info )in /proc/acpi/fan or /proc/acpi/thermal_zone) and i'm not sure if everything is working properly. I recompiled my kernel manually, so ACPI is included in it (it's not loading as a module, but is compiled into kernel), and i'm pretty sure i did it properly. On boot everything seems to work normaly, there are no ACPI errors when i scroll through dmesg output, and ACPi plug&play support is working. I've been looking for possible solutions on internet, and someone mentioned that X window system can lock /acpi/proc/event file sometimes, so i did
"lsof /proc/acpi/event"
and the output was acpid. I'm now seriously confused, does anybody have any idea if this is a problem(as i'm not using linux for long, i know how to do some things but i'm not an experienced user yet). I'm running 2.6.18.1 vanilla kernel. I haven't posted any files or outputs, as i'm not sure what i should post. If there are files that need to be attached, i'll post them, just tell me what you need. Thanks for any help

Simon Bridge · 11-15-2006, 02:53 AM

Quote:

but when i try to cat /proc/acpi/event or start acpid i get the following message -
"cannot read /proc/acpi/event. Device or resource busy".

That's what I get too. Do you have any reason to believe you'd get anything different?

Quote:

I consider this to be a problem, as i have no thermal or fan info )in /proc/acpi/fan or /proc/acpi/thermal_zone) and i'm not sure if everything is working properly.

... hmmm, maybe that's not supported.

Note: I don't have any thermal infor in /proc/acpi/thermal_zone either... for me, the information is in the "THRM" subdirectory, amongst a range of files:

Code:

$ ls /proc/acpi/thermal_zone/THRM
cooling_mode  polling_frequency  state  temperature  trip_points

There is nothing in /proc/acpi/fan for me either - but my fan starts and stops OK.

jets0n · 11-15-2006, 08:28 AM

Quote:

Originally Posted by Simon Bridge

Note: I don't have any thermal infor in /proc/acpi/thermal_zone either... for me, the information is in the "THRM" subdirectory, amongst a range of files:

Code:

$ ls /proc/acpi/thermal_zone/THRM
cooling_mode  polling_frequency  state  temperature  trip_points

There is nothing in /proc/acpi/fan for me either - but my fan starts and stops OK.

Thanks 4 the reply. The thing that bothers me is that you have THRM folder in /proc/acpi/thermal_zone, while my /proc/acpi/thermal_zone folder is empty. i don't mind the fan control, but i mind the fact that i have no trip point or anything, so my fan works weird.

Just to update this thread, i managed to get the temperature readings 4 my proc, using omnibook drivers from sourceforge.

jets0n · 11-16-2006, 06:37 AM

Sorry 4 bumping the thread, but i managed to find some new info, which might help in resolving the /proc/acpi/thermal_zone problem. According to the article i managed to google

, that folder is empty "because of power-saving c-csates in idle" (according to Adrian Bunk), although i do not understand that.

Hopefully this might be of use to somebody experiencing same ACPI troubles

jets0n · 11-16-2006, 06:38 AM

Here is the link to the mentioned article:

http://lkml.org/lkml/2004/11/22/355

(3 post rule)

Simon Bridge · 11-17-2006, 02:28 AM

The c-state mentioned (misspelled) is the CPU-sleep state.
I used to know what C1 C2 etc meant, but it's been too long since I was hacking acpi. The states are supplied by the dsdt in BIOS.

The reply seems somewhat glib - I don't know why a high c-state should mean nothing in /proc/acpi/thermal_zone ... perhaps it is because temperature monitoring is done elsewhere. Anyway - you can see the c-states for yourself in

/proc/acpi/processor/*/power ... i.e.

Code:

$ cat /proc/acpi/processor/*/power
active state:            C2
max_cstate:              C8
bus master activity:     ffffffff
states:
    C1:                  type[C1] promotion[C2] demotion[--] latency[000] usage[00036390]
   *C2:                  type[C2] promotion[C3] demotion[C1] latency[099] usage[00288293]
    C3:                  type[C3] promotion[--] demotion[C2] latency[999] usage[00000114]

http://acpi.sourceforge.net/document...processor.html

jets0n · 11-17-2006, 05:22 PM

Thanks 4 the info :thumbs up:. this seems to be a general issue with my laptop's BIOS version, as i have the same problem with Mandriva(/proc/acpi/thermal_zone is an empty folder). i'll try to find a solution, and post new replies has i come along