T60p Unplugged Noise

[nekt]

Long time reader, first time poster. Used the info from this board in the decision making process for buying a t60p. Have my t60p just about configured with slack linux.

Everything seems to be running well. HDaps is running, though there I havent tested the parking patch for 2.6.17 (current running kernel).

An issue that is causing me some grief is that whenever the ac is unplugged from the system, there seems to be a slight hiss. This hiss is not from the fan as I have patched the kernel for fan control and with the fan off the hiss is still audible.

A strange factor seems to be system load. With high system load (or high graphics output - if the kernel compile scrolling text is high graphics load) the hiss goes away. When the machine is idle the hiss is very constant.

The sound is audible, not loud, but it is there and constant. The sound is also not present under windows. Anyone notice similar sounds?



Also, had an issue with a parking patch for kernel 2.6.16.19. When hdapsd tried to read /sys/devices/platform/hdaps/position, it would not be readable, resulting in the machine being froze. This would happen at random times after the hdaps had worked perfectly for 5-60 min. Never let it sit in this state so it was never very long before it happened. Had to yank the battery 2x because of this. The hiss was present before this, just thought someone might have had similar issues as well.

Thanks in advance.

[lagitus]

I've yet to solve this very same problem on my T60. Apparently it has something to do with CPU frequencies.

Here are some links that might help:
http://mailman.linux-thinkpad.org/piper ... 34753.html
http://www.thinkwiki.org/wiki/Problem_w ... tch_noises

[lagitus]

Setting /sys/module/processor/parameters/max_cstate to 2 as explained in the second link fixed it for me!