On 8/28/2010 5:20 AM, Jean Delvare wrote:
On Wed, 25 Aug 2010 02:53:20 -0300, ICMP Request wrote:
On 8/25/2010 2:43 AM, ICMP Request wrote:
Hello! I'm planning to install lm_sensors in my Linux platform using
Gentoo, but I've got a little worried when I've read the following
about lm_sensors on Gentoo Wiki:
"Warning: Be careful when activating sensors, like i2c, in the kernel.
On some systems this might stop the fans from working and can disable
the ACPI system-overheat shutdown as well. This will cause your
computer to freeze at best, or may even cause serious hardware damage.
This point was addressed in kernel 2.6.32. If ACPI requested the I/O
ports of your hardware monitoring device (or SMBus controller, for
I2C/SMBus hardware monitoring devices), then native Linux drivers won't
touch it.
* See the lm_sensors website for a problematic hardware list.
I am not aware of any such list on our website.
* Using lm_sensors on IBM ThinkPads is especially not advised"
This last item is way outdated and should be removed. I'm running
lm-sensors on my own ThinkPad laptop and it works just fine.
Well, I believe my hardware is in the supported list, but to avoid any
problems, I would like to disable fan control under
Linux/acpi/lm_sensors and any application using sensors, so they
cannot turn my fan off. Fan would be purely controlled by hardware.
Can it be done by simply disabling the "fan" as built-in or module
under ACPI?
Under Linux 2.6 Kernel:
Power management and ACPI options -> ACPI (Advanced Configuration and
Power Interface) Support -> Fan =n
Or do I have to do something more complex?
I'm not sure what exactly loading the acpi "fan" driver does, but
probably not much. I think it is simply responsible for stopping the
fan when you suspend the machine.
Oh sorry, I've forgot to mention that I wish to disable turning my fan
off but I still want to enable full acpi/lm_sensors to check my cpu
temp/status, battery state, cpu freq scaling, etc. So is this possible
to by doing what I mentioned above disable this single option but enable
all the rest?
I don't think it makes much sense to disable the ACPI fan driver. If
anything is actually changing the fan's speed, it's not the ACPI fan
driver. If you don't want software-based fan speed control, then just
don't run pwmconfig, and you'll be safe.
Anyway, I can't add much as long as you don't tell us what your
hardware is, and how you believe the fan speed control (if there is
any) is achieved. Some machines have setting for this in the BIOS, some
don't. Some machines have ACPI-based control, some have monitoring
chips which can be programmed for automatic fan speed control.
Hello Jean! Thanks so much for answering! So, as far as I understood
about your mail:
- On kernels 2.6.32 and higher, ACPI System Overheat Shutdown will no
longer be disabled by any sensors-related driver, making it impossible
to lm_sensors damage any hardware through overheat.
- There is NOT a list of problematic hardware at lm_sensors website (I
also figured there was none).
- Recent lm_sensors versions on recent Kernels will not have any problem
with an IBM Thinkpad.
- ACPI fan driver does not control the fan speed, neither is responsible
for turning them off unless on shutdown. It is also not a dependency
required by lm_sensors to work with the fans on a machine or turning
them off, they are both unrelated.
Are these affirmations above all true? Or did I misunderstood something?
I was not really thinking about my machine in special, it was more a
general question if one day I need to install lm_sensors in many
machines with different configurations. For my machine, I've compiled
2.6.34 Linux Kernel and loaded all hardware monitoring drivers as
modules, as well as i2c, etc. and the only driver lm_sensors detected
was "coretemp", which is the temperature monitoring driver for intel
core2. There is also no option to enable/disable software fan control on
BIOS.
So it seems that my machine is safe, by the simple lack of drivers to
control the fan or even see anything but the processor temperature.
I'm about to buy a motherboard with Intel P55 Express Chipset and core
i5 processor, and I hope it doesn't present problems on kernel 2.6.34+
and lm_sensors 3.1.2+ related to hardware damaging.
But, as you said, I should not worry about any machine because on recent
kernel and lm_sensors versions, they are all immune to damage through
overheat? Even the IBM Thinkpads?
If you and/or more can confirm that I understood it correct, I will be
very grateful and also suggest Gentoo Linux Community to upgrade their
wiki, linking this thread for reference.
Thanks again!
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