[ltp] X41 high pitched noise

[Till Maas]

Hi,

I just got a X41 and found a strange problem. In the archive of this 
mailinglist I found other haven a similar problem with a T41 but they didn't 
have a soulution.

So, here's my problem. When I boot Linux with acpi support I hear some 
annoying high pitched noise through a speaker but not through earphones. 
Booting with acpi=off kernel option make the noise go away and it seems it 
starts when acpi modules are loaded. Another way to get rid of the noise is 
to play some sound even with the soundcard muted. dd to or from /dev/dsp 
with /dev/zero resp. /dev/null shuts the sound down as well.

Has anyone any suggestions how I could get rid of the sound in a more 
convinient way, maybe fixing it in acpi or alsa.

It seems not to be the wlan card because even without it the noise appears. 
Booting windows, there isn't that noise, either, but this could be because of 
the windows "soundserver" (starting jackd under linux helps to stop the noise 
as well, but costs more battery power).

Greetings,
Till