Comment 10 for bug 463940

Michael Bommarito wrote:
> I'll get some more data up later tonight - I booted back to Win7 to get
> some baseline temperatures for my machine and will need to be AFK for a
> few hours. Not sure if these are comparable to the Envy given that very
> different materials are used, but the dv6t-2000 runs between 45-70C on
> the CPU and 40-52C on the disk in Windows 7.
>
I didn't get any readings from Win7 (I wiped :), but that sounds about
right for regular use.
The sensor I got on-line by massaging the DSDT indicated a temperature
of around 52C, with a critical temperature of 97C. I'm guessing this was
the HDD temperature (the remaining dmesg errors after fixing the DSDT
seem to hint there's problems with the CPU thermal zone, so that leaves
the HDD and the GPU)
> I'll try under Jaunty again later tonight. How did you fix your DSDT?
>
This link deals with getting the tools for extracting and compiling a
new DSDT. Note that custom DSDTs are no longer supported as of 9.10.

http://www.uluga.ubuntuforums.org/showthread.php?t=1036051

I'll attached a copy of the 'fixed' DSDT source, but be careful with
using it on your machine; we don't know if the BIOS/hardware is the same
yet. Your CPU is different to start of with, so that will need fixing.

The things I fixed were;

* Shifting around code, so that methods and constants were
known/declared before being used.
* I commented out some code in the thermal zone section that would check
for the OS Identifier. It would cause an implicit return (i.e. not
returning *any* value, causing the critical temperature bug). See
https://wiki.edubuntu.org/LaptopTestingTeam/HPdv5z for a similar sort of
situation and how to fix it.
* I commented out code "FPED ()" where no code was allowed (i.e. no
executable code at module level allowed). Didn't seem to adversely
affect anything...

> I was also considering pulling a fresh kernel from
> http://kernel.ubuntu.com/git , but I was concerned about compiling a
> kernel without a fan...
>
Ok, this is a decidedly low-tech solution; if your machine has a metal
alloy casing like my Envy 15, then the heat dissipation works through
the body as well. I simply raised the laptops and put a fan on the spot
that gets hottest (bottom side under the touchpad in case of the Envy
15). That actually made it run cool enough for installing/diganostics.
Frequency scaling is working fine, so if you would force all cores to
run at the lowest frequency possible (there's a gnome applet you can put
on your taskbar), you might get away with compiling a new kernel at a
reasonable temperature.

I read somewhere else that HP let their fans run all the time, be it at
a lower setting, so that there is at least *some* heat dissipation
performed by the laptop itself (but clearly not enough). This does
indeed seem to be the case on the Envy 15.