Bug 41612 - thermal provides suspect temp values on Acer Travelmate 8172T
Summary: thermal provides suspect temp values on Acer Travelmate 8172T
Alias: None
Product: ACPI
Classification: Unclassified
Component: BIOS (show other bugs)
Hardware: All Linux
: P1 normal
Assignee: acpi_bios
Depends on:
Reported: 2011-08-23 14:04 UTC by Leho Kraav
Modified: 2013-01-29 00:00 UTC (History)
2 users (show)

See Also:
Kernel Version: 3.0.2-pf
Tree: Mainline
Regression: No

DSDT (407.68 KB, text/plain)
2012-05-24 08:14 UTC, Leho Kraav

Description Leho Kraav 2011-08-23 14:04:13 UTC
laptop: http://support.acer.com/us/en/product/default.aspx?tab=1&modelId=2431

my original motivation was to find out how to better control fans on this laptop, all the way down to modifying DSDT if i have to. i had a feeling it was more quiet running Windows. on Linux, fans start spinning at audible speed as soon as one core temperature goes above 47C.

digging around in /sys/class/thermal, looking to find out what's available and if there are any levers i can pull to make the fans speed up at some higher threshold, i'm seeing some strange values.

$ find /sys/class/thermal/thermal_zone*/ -exec grep --color -H '' {} \;
grep: /sys/class/thermal/thermal_zone0/power/autosuspend_delay_ms: Input/output error
grep: /sys/class/thermal/thermal_zone1/power/autosuspend_delay_ms: Input/output error

$ sensors
Adapter: Virtual device
temp1:         +6.8°C  (crit = +100.0°C)
temp2:         +5.8°C  (crit = +119.8°C)

Adapter: ISA adapter
Core 0:       +41.0°C  (high = +95.0°C, crit = +105.0°C)
Core 2:       +47.0°C  (high = +95.0°C, crit = +105.0°C)

it's the 6800 and 5800 entries that look suspect to me. i also am not seeing the 47000 trip point anywhere in sysfs, yet based on audible evidence, it clearly is some kind of a trip point.

some compatibility, broken bios issue? something fixable?
Comment 1 Zhang Rui 2012-01-18 05:35:56 UTC
please attach the acpidump output of this laptop.

Can you please verify if the problem still exists in the latest upstream
Comment 2 Zhang Rui 2012-05-24 08:07:05 UTC
bug closed as there is no response from the bug reporter.
please feel free to reopen it if the problem still exists in the latest upstream kernel.
Comment 3 Leho Kraav 2012-05-24 08:11:59 UTC
Thanks for the ping, I can provide acpidump output shortly.
Comment 4 Leho Kraav 2012-05-24 08:14:01 UTC
Created attachment 73370 [details]

In the meanwhile, does this help any?
Comment 5 Zhang Rui 2012-11-28 07:06:42 UTC
            Method (_TMP, 0, Serialized)
                If (LEqual (SWSF, One))
                    Return (0x0FA0)

                Return (0x0AF0)
            Method (_TMP, 0, Serialized)
                Return (0x0AE6)

You have really buggy BIOS for your laptop.
The ACPI thermal sensor returns fix temperature, which always equals 6.8C and 5.8C.

so the ACPI thermal control will never work unless it is fixed in the BIOS.

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