CPU fan not working after suspend to RAM

[gianni2638]

Hello everyone, I'm a new Fedora user, I'm running F12 x86_64 on a Dell Studio 17 (1737) laptop and everything is fine for me with this distro except for one or two issues.
When I use the suspend to RAM functionality (Acpi state S3) everything works fine but when the computer resumes from suspend state the CPU fan is not working any more and the output of acpitool is:
Battery #1 : charged, 100.0%, 00:00:00
AC adapter : on-line
Thermal zone 1 : ok, 0 C
Thermal zone 2 : ok, 0 C
Thermal zone 3 : ok, 0 C
all the thermal zones temperatures seem to be zero decimal degrees!!!
Without the fan running the temperature grows and when it becomes critical (after a couple of hours, depending on CPU usage intensity) the computer turns off suddenly losing all unsaved data.
If I suspend to disk (hibernate, Acpi state S4) there is no problem, the fan starts normally on resume and the acpitool output is:
Battery #1 : charged, 100.0%, 00:00:00
AC adapter : on-line
Thermal zone 1 : ok, 51 C
Thermal zone 2 : ok, 49 C
Thermal zone 3 : ok, 55 C
with reasonable temperature values.
The output of acpitool --fan is:
Fan : <not available>

I have no idea on how how to carry out further debug on this problem in order to fix it. Many thanks for any suggestion.

[tashirosgt]

I don't have hardware like yours. As to attempts to debug the problem, I tried (out of curiousity) the steps on http://wiki.archlinux.org/index.php/ACPI_modules and many of them work. (I didn't find any rc.conf in Fedora Core 12 and I don't know where the "central control" of the modules is handled. Surely some other member can tell us this. We need to know where we can set debug parameters to be passed to the modules when they run.)

I also found web pages where people had combined the command "watch" with "acpitool" or "acpi_listen" to monitor the acpi process. I think you also have to be sure that the version of acpitool that you have is uptodate with respect to the kernel. One page said that the kernel developers frequently make changes that break acpitool.

[tucsonjohn]

I have the same problem. (but I am running unstable debian). I have a Dell Studio 15 running x86_64. I have spent quite a bit of time on the problem. I find that if I unplug the AC power, then the thermal zones start reporting
reasonable values and the fan comes on when it should. I don't have to leave the AC off, it seems that the AC offline event repairs the problem. I can plug it back in after a second or two.

The problem with this is 1) not convenient 2) dangerous (what if I forget) 3) can't suspend/resume unless I have the power supply at hand.

I tried restarting all kinds of services, removing all kinds of modules, before and after suspend... Nothing works. Removing the 'thermal' kernel module before suspending and then inserting it after resuming did not work (but it did cause all keyboard, mouse input to have no effect so I had to power off. That may have been unrelated)

I noticed in the system log that ACPI stops and starts a bunch of kernel functions when going to S3 mode. The last one stopped and the first one resumed is 'thermal'. I don't know if thats relevant.

I would like to find a way to simulate an AC offline event so that I can put it in a script. Better would be to find why this AC offline thing fixes the problem.

---------- Post added at 04:32 AM CST ---------- Previous post was at 04:21 AM CST ----------

Here is a post about the same problem; or at least
very similar.

http://markmail.org/message/qwbuuqn3ivr3npp2

[tucsonjohn]

Here is another report of the same problem:
https://bugzilla.redhat.com/show_bug.cgi?id=532161

Note that all three of us have Dell Studio laptops.
No one but me mentioned that unplugging the power
adaptor fixes the problem.

Here are some details on my system:
hardware: Dell Studio 1537
dist: Debian unstable
kernel: 2.6.32.5
video driver: fglrx 9.12
suspend software: pm-suspend v 1.2.6.1

Other notes: removing the 'thermal' module causes
the thermal zone directories to disappear from /proc/acpi. So 'acpi -V' and acpid and anything that
reads these will no longer see the thermal zone temps.
But I notice that, if I have not done a suspend/resumeand use the CPU heavily and the graphics, that the fans still adjust to the temperature.
So, somehow the system is still reading these temperatures and responding with fans with the 'thermal' module removed.

But, with the suspend/resume problem, everyone notices that the fans no longer come on when the
system is hot. The thermal zone module reports 0 for
the temperatures. If the system is hot and I unplug the
AC, the fans come on immediately as the sensors begin working again.

[tucsonjohn]

Now running 2.6.31.9, I do not have the problem.
(but lid close no longer works; pm-suspend does
work) It may have to do with kernel configuration options, but sifting through them and comparing them without knowing what you are looking for is extremely
tedious and timeconsuming.

Among problems with recent kernels are: filesystem corruption on every shutdown, wifi dropping regularly, backlight coming up stuck in some random state. I am trying to find one kernel that has none of the worst ones. But, for every problem, I can find a kernel that
does not have it.