Cpufreq/ACPI problem? (basically still is: "Re: Problem with IBM Thinkpad T30 shutting down due to high temperatures")

[Christian Walther]

Hi,

thank you for all your feedback.
I won't answer all replies in detail, but will summarise what I did to
give you some sort of report.
Doug made me think about the beginning of this situation. I can't tell
you for sure that I had the T30 working flawlessly, because I took the
original install from another, older thinkpad.
But I did change some BIOS settings, Interrupt settings, mainly, that
seem to cause problems with my Wireless NIC in the past. So I restored
the BIOS defaults. This seems to make the problem disappear, but to be
honest: I'm not sure if I messed up the ACPI table at all, or if this
is some sort of performance issue, because I now have all IO bound
devices on IRQ 11:

vgapci0: <VGA-compatible display> port 0x3000-0x30ff mem
0xe8000000-0xefffffff,0xd0100000-0xd010ffff irq 11 at device 0.0 on
pci1
uhci0: <Intel 82801CA/CAM (ICH3) USB controller USB-A> port
0x1800-0x181f irq 11 at device 29.0 on pci0
uhci1: <Intel 82801CA/CAM (ICH3) USB controller USB-B> port
0x1820-0x183f irq 11 at device 29.1 on pci0
uhci2: <Intel 82801CA/CAM (ICH3) USB controller USB-C> port
0x1840-0x185f irq 11 at device 29.2 on pci0
cbb0: <TI1520 PCI-CardBus Bridge> mem 0x50000000-0x50000fff irq 11 at
device 0.0 on pci2
cbb1: <TI1520 PCI-CardBus Bridge> mem 0x51000000-0x51000fff irq 11 at
device 0.1 on pci2
fxp0: <Intel 82801CAM (ICH3) Pro/100 VE Ethernet> port 0x8000-0x803f
mem 0xd0200000-0xd0200fff irq 11 at device 8.0 on pci2
pcm0: <Intel ICH3 (82801CA)> port 0x1c00-0x1cff,0x18c0-0x18ff irq 11
at device 31.5 on pci0

This causes screen refresh problems (e.g. urxvt isn't able to draw new
lines as expected). Still, this didn't resolve the issue, so I took a
look at acpi_thermal.
Right now I have the following set in /etc/sysctl.conf

hw.acpi.thermal.user_override=1
hw.acpi.thermal.tz0._PSV=84.0C
hw.acpi.thermal.polling_rate=2

This basically gives me:

# sysctl -a|egrep "(temp|freq|acpi.therm|acpi_ibm.*fan)"
kern.acct_chkfreq: 15
kern.timecounter.tc.i8254.frequency: 1193182
kern.timecounter.tc.ACPI-fast.frequency: 3579545
kern.timecounter.tc.TSC.frequency: 2000000000
net.inet.sctp.sack_freq: 2
net.inet6.ip6.use_tempaddr: 0
net.inet6.ip6.temppltime: 86400
net.inet6.ip6.tempvltime: 604800
net.inet6.ip6.prefer_tempaddr: 0
debug.cpufreq.verbose: 0
debug.cpufreq.lowest: 0
hw.acpi.thermal.min_runtime: 0
hw.acpi.thermal.polling_rate: 2
hw.acpi.thermal.user_override: 1
hw.acpi.thermal.tz0.temperature: 62.0C
hw.acpi.thermal.tz0.active: 0
hw.acpi.thermal.tz0.passive_cooling: 1
hw.acpi.thermal.tz0.thermal_flags: 0
hw.acpi.thermal.tz0._PSV: 84.0C
hw.acpi.thermal.tz0._HOT: -1
hw.acpi.thermal.tz0._CRT: 92.0C
hw.acpi.thermal.tz0._ACx: -1 -1 -1 -1 -1 -1 -1 -1 -1 -1
hw.acpi.thermal.tz0._TC1: 5
hw.acpi.thermal.tz0._TC2: 3
hw.acpi.thermal.tz0._TSP: 600
machdep.acpi_timer_freq: 3579545
machdep.tsc_freq: 2000000000
machdep.i8254_freq: 1193182
dev.acpi_ibm.0.fan_speed: 4465
dev.acpi_ibm.0.fan_level: 0
dev.acpi_ibm.0.fan: 1
dev.cpu.0.freq: 2000
dev.cpu.0.freq_levels: 2000/0 1750/0 1500/0 1250/0 1200/0 1050/0 900/0
750/0 600/0 450/0 300/0
dev.acpi_perf.0.freq_settings: 2000/0 1200/0
dev.cpufreq.0.%driver: cpufreq
dev.cpufreq.0.%parent: cpu0
dev.p4tcc.0.freq_settings: 10000/-1 8750/-1 7500/-1 6250/-1 5000/-1
3750/-1 2500/-1

Active cooling doesn't seem to be supported. There is a fan of course,
and I can even set a fan level via dev.acpi_ibm.0.fan, but this is not
related to  hw.acpi.thermal.tz0._HOT and hw.acpi.thermal.tz0._ACx
(which is read only anyway).
According to dev.acpi_ibm.0.fan_speed the speed of the fan is
something between 4450 and 4780.

The interesting bit here is cpufreq and how it behaves. Lets have a
look at the output of the following loop:
# while true ; do temp=$( sysctl hw.acpi.thermal.tz0.temperature ) ;
freq=$( sysctl dev.cpu.0.freq ) ; printf "%4s %4s\n" $freq[17,$#freq]
$temp[34,$#temp] ; sleep 2 ; done
2000 84.0C
2000 85.0C
2000 85.0C
2000 85.0C
2000 86.0C
 300 86.0C
 300 86.0C
 300 86.0C
 300 85.0C
 300 84.0C
 300 82.0C
 300 81.0C

It appears that cpufreq requires at least eight seconds to reduce the
frequency. There are two issues I'm seeing here: Firstly
hw.acpi.thermal.polling_rate: 2 Either I get this one wrong, or
cpufreq doesn't react after every poll. I've seen this in the past,
but not as good as now. Secondly cpufreq doesn't seem to use
dev.cpu.0.freq_levels at all, but drop to the lowest frequency
available.
And it does the same the other way round, too.

I was able to built a new userland and kernel yesterday, so I'll do
some more testing with a decent system after a clean reboot. The
kernel I want to use next time will be plain GENERIC. This does not
turn on support for active cooling in any way, something I was
thinking about because according to acpi_ibm fan levels from 0 to 7
are supported. And setting them manually works, so I guess this should
be possible with acpi.thermal, too. Or am I mistaken and acpi.thermal
and acpi_ibm don't interact with each other?

The interesting bit here is cpufreq: Is the behaviour normal and to be
expected, or is this possibly a bug?

Regards
Christian Walther