Re: 3.13.?: Strange / dangerous fan policy...

[Guenter Roeck]

On 03/08/2014 04:10 PM, Manuel Krause wrote:
> On 2014-03-08 16:59, Guenter Roeck wrote:
> > On 03/08/2014 03:08 AM, Jean Delvare wrote:
> > > On Fri, 7 Mar 2014 14:52:30 -0800, Guenter Roeck wrote:
> > > > On Fri, Mar 07, 2014 at 11:04:29PM +0100, Manuel Krause wrote:
> > > > > Hi, and thanks for the quick response!
> > > > > No special fancy "fan control policy". 'fancontrol' isn't up or
> > > > > running.
> > > > > Vanilla kernels 3.11.* and 3.12.* had been working on here
> > > > > without
> > > > > any extra work.
> > > > > --
> > > > > # sensors
> > > > > acpitz-virtual-0
> > > > > Adapter: Virtual device
> > > > > temp1:        +71.0°C  (crit = +256.0°C)
> > > > > temp2:        +69.0°C  (crit = +110.0°C)
> > > > > temp3:        +52.0°C  (crit = +105.0°C)
> > > > > temp4:        +25.0°C  (crit = +110.0°C)
> > > > > temp5:        +58.0°C  (crit = +110.0°C)
> > > > >
> > > > > coretemp-isa-0000
> > > > > Adapter: ISA adapter
> > > > > Core 0:       +62.0°C  (high = +105.0°C, crit = +105.0°C)
> > > > > Core 1:       +60.0°C  (high = +105.0°C, crit = +105.0°C)
> > > > > --
> > > > > My notebook (HP/Compaq 6730b) does not have a seperate fan
> > > > > sensor.
> > > > > This is with 3.12.13 with my normal workload.
> > > > >
> > > > > Please, trust my above mentionned values of 94 °C vs. 74°C as I
> > > > > don't like to boot 3.13.6 anymore, to avoid harm to the
> > > > > notebook's
> > > > > casing.
> > > >
> > > > Understood. Unfortunately, we'll need to get information
> > > > from the new kernel to be able to track down the problem.
> > >
> > > Indeed. Not only the run-time temperatures, but also the high
> > > and crit
> > > limits.
> > >
> > > > > But I'd do to test any improvement-patch.
> > > >
> > > > So far I have no idea what is going on. I don't see anything
> > > > in the
> > > > drivers providing above data that would explain the behavior,
> > > > but I might be missing something.
> > >
> > > Looks like a regression in the acpi subsystem or in power
> > > management,
> > > not hwmon. Hwmon is merely reporting the temperatures, it's not
> > > responsible for the actual temperatures.
> >
> > I would agree. I don't think we have enough information to be sure,
> > though. There might be some unintended interaction or interference.
> >
> > gpu is a good hint ... for example, look at commit b9ed919f1c8
> > (drm/nouveau/drm/pm: remove everything except the hwmon interfaces
> > to THERM). nouveau does export pwm and fan control information,
> > so any change in that code may have unintended side effects.
> > Similar, I don't know how ec39f64bba (drm/radeon/dpm: Convert to
> > use devm_hwmon_register_with_groups) could have the observed impact,
> > as it is purely passive, but I prefer to be rather safe than sorry.
> >
> > This problem has now been submitted into bugzilla as
> > https://bugzilla.kernel.org/show_bug.cgi?id=71711.
> >
> > Guenter
>
> Sorry, for beeing late, had to search for/accumulate much info for you...
> I hope, you like me to put it into one answer to you all CCing you.
>
> My GFX is a GM45 Intel (mobile), shared memory, running the opensource Mesa drivers/extensions.
> kernel-module: i915
>
> According to the output of 'cpupower': I have
> CPUidle driver: acpi_idle
> CPUidle governor: menu
>
> CPUfreq:
>    driver: acpi-cpufreq
>    available cpufreq governors: ondemand, performance
> -
> And "ondemand" is running.
> --
>
> # sensors
> acpitz-virtual-0
> Adapter: Virtual device
> temp1:        +41.0°C  (crit = +256.0°C)
> temp2:        +92.0°C  (crit = +110.0°C)
> temp3:        +71.0°C  (crit = +105.0°C)
> temp4:        +26.5°C  (crit = +110.0°C)
> temp5:        +25.0°C  (crit = +110.0°C)
>
> coretemp-isa-0000
> Adapter: ISA adapter
> Core 0:       +86.0°C  (high = +105.0°C, crit = +105.0°C)
> Core 1:       +84.0°C  (high = +105.0°C, crit = +105.0°C)
>
> FROM a critical "smelly" situation today, kernel-compilation, fan @100%.
> --
>
> Additional findings:
>
> Identification from bootup ACPI initialisation vs. sensors:
> temp1 = DTSZ
> temp2 = CPUZ --> triggering Cooling in 3.12.13 if > 74°C
> temp3 = SKNZ
> temp4 = BATZ "Battery Zone" always calm ~ +6°C of ambient T
> temp5 = FDTZ --- in 3.12.13 a representation of the cooling-fan (25 - 45 - 58 - max?)
> Core 0 & Core 1 are the internal CPU T sensors.
>
> With the 3.13.x (.5+) kernels the first gatherered cooling settings from bootup do stay forever. Means, rebooting a hot system will get a FDTZ @45°C+ and won't make any problems, as it does cool enough (even for kernel compiling on here). If it gets 25°C @bootup the system goes into emergency cooling somewhen. Same is with a suspend/resume.
>
> Kernel 3.12.13 adjusts the cooling on it's own, but appropriately.

Hi Manuel,

thanks a lot for the additional information.

I added this exchange to bugzilla (https://bugzilla.kernel.org/show_bug.cgi?id=71711).
This is pretty much all I can do at this point; I have no idea what
is going on. Some change in ACPI would be my guess, but I did not see
anything catching my eye when looking through the ACPI code.

Guenter

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