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Date:      Sat, 21 Dec 2013 16:13:05 +1100 (EST)
From:      Ian Smith <smithi@nimnet.asn.au>
To:        ito <egunther@warwick.net>
Cc:        freebsd-acpi@freebsd.org
Subject:   Re: loud fan pavilion ze2000
Message-ID:  <20131221152703.E25305@sola.nimnet.asn.au>
In-Reply-To: <1387551635.2533.21.camel@res-cmts>
References:  <1387551635.2533.21.camel@res-cmts>

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On Fri, 20 Dec 2013 10:00:35 -0500, ito wrote:
 > Hi,
 > 
 > I posted a question to the freebsd forums (under mobile computing) in
 > which I was seeking help with a old laptop (hp pavilion ze2000) because
 > of fan noise.  The problem is not really that the fan is too loud,
 > although that is part of it, it is that it cycles frequently (about
 > every 21 sec, at average use).  I seems to me now that maybe here would
 > be more appropriate.
 > I am having trouble finding information about the acpi functions in
 > particular.  So I thought maybe I could get help here.  For instance,
 > according to the information below, is the passive cooling set to start
 > at 85.0C (Celsius) which would be 185 Fahrenheit?  Is this very hot to
 > start to cool down passively?  Why is active cooling set to -1?  Where
 > do I find the definitions of these things... like the flags?

Starting at the end, see acpi_thermal(4) ie 'man acpi_thermal'.  Not 
sure about the flags, you may need to consult the sources.

Apparently your BIOS is running the fan (ie active cooling) so there's 
no control of it you can access here.  Both .active: -1 and .ACx: -1.. 
indicate that, and the fact that your fan is cycling off and on.  The 
usual advice about cleaning out the airways with compressed air (or 
well-directed moderate vacuum) applies.  Old fans will sometimes need 
replacing, though it's when they stop being noisy (ie stop running), or 
are making grinding sounds (bearings) that you have to worry.

You might want to check sysctl hw.acpi.thermal.tz0.temperature through a 
few fan cycles to see what internal temperature setpoints it's using for 
fan on and off, usually with some hysteresis either way.  60C is not 
hot, though likely hot enough to be running the fan at some level.

85C is pretty warm, when passive cooling kicks in (throttling or 
otherwise slowing the CPU to reduce heat), and has nothing to do with 
the fan, although it should also be running flat out at that time.  You 
may need to monitor sysctl dev.cpu.0.freq to see that happening, if freq 
is variable.  95C should initiate an emergency shutdown.

You should be able to set .user_override=1 then temporarily set ._PSV a 
good deal lower (say 70C) and make it work hard ('dd if=/dev/random 
of=/dev/null' works for me :) if you want to see what your system does 
to implement passive cooling.  Old Celerons usually can be throttled to 
at least half speed, if not the full range of 1/8 to 7/8 max CPU speed.

cheers, Ian

 > ----sysctl -a | grep thermal
 > 
 > hw.acpi.thermal.min.runtime: 0
 > hw.acpi.thermal.polling_rate: 10
 > hw.acpi.thermal.user_override: 0
 > hw.acpi.thermal.tz0.temperature: 60.0C
 > 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: 85.0C
 > hw.acpi.thermal.tz0._HOT: -1
 > hw.acpi.thermal.tz0._CRT: 95.0C
 > hw.acpi.thermal.tz0._ACx: -1 -1 -1 -1 -1 -1 -1 -1 -1 -1
 > hw.acpi.thermal.tz0._TC1: 2
 > hw.acpi.thermal.tz0._TC2: 3
 > hw.acpi.thermal.tz0._TSP: 50
 > 
 > 
 > Any insight would be appreciated,
 > 
 > -eg



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