[Libreboot-dev] 20141015 Release/X60S: high pitched noise

[Robert Alessi]

Hi,

I hope this does not go to the wrong list.

I upgraded to 20141015 yesterday from the previous stable release
which I have been using for months.  But as I found a way to remove
the noise before the guide in libreboot/docs/misc was published, I
never used powertop.  As a matter of fact I just installed and
'enabled' tlp (on Parabola) to get the rid of the buzz.

But I soon as I upgraded to 20141015 it went back depite tlp still
running.  So I tried powertop, but unsuccessfully: 'powertop
--auto-tune' always crashed with core dumped.  I have to say that I did
not try to 'calibrate' it.

Then I noticed that since I upgraded, the system status indicator #3
(see http://support.lenovo.com/us/en/docs/MIGR-62866, on page 47), the
one next to the BT status indicator, starting from the left, stays
lit. This is the Wireless WAN status indicator.  So I tried to
'blacklist' the 'sierra' module, with no results.

Finally, going back to '/etc/default/tlp', I added the following line:
USB_BLACKLIST_WWAN=0

just  below these:
# WWAN devices are excluded from usb autosuspend:
# 0=do not exclude / 1=exclude
# Note: works for ids 05c6:* 0bdb:* 1199:* only

This removed all of the noise.  It seems that the device has to be
autosuspended.  To be more precise: there is absolutely no noise if
the screen brightness is set to 100%. If I reduce brightness, some
noise is back, but not a whining, bothering one.  I would say that I
can hear it, while not everyone can: it is a very slight, high pitched
one.

I hope this may help.  I will try to look into this further on.

Merry Christmas Everyone!

pgp_La3EhIvR6.pgp
Description: PGP signature