[ltp] Re: High-pitch noise on a T60

[Thomas Kahle]

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Hi,

I have the same problem. I cannot accept to disable C3 states and on the
other hand unloading uhci-hcd removes the noise.

So, some observations:

- -) Maybe it's the fingerprintreader ?
It is an USB device, it's cheap, its low-speed ... ?
- -) removing the module, and reinserting it instantly gives back the
noise while removing it and waiting 2 minutes before loading it back
removes the noise ... for some time.

thanks
tom

Michael Karcher wrote:
| Am Mittwoch, den 23.04.2008, 18:01 +0200 schrieb Elias Oltmanns:
|> Peter Lemken <ibm-thinkpad@bloatware.de> wrote:
|>> Howdy,
|>>
|>> I - like many others - have the high-pitch noise phenomenon when
running on
|>> battery.
|>>
|>> rmmod uhci_hcd completely solves the problem - but since my mouse is
a USB 1.1
|>> device, I am left without a mouse.
|> Perhaps you might want to give
|>
|> CONFIG_HZ_100=y
| Nowadays, one usually wants CONFIG_NO_HZ=y to use dynamic ticks. If some
| high-pitched noise appears, something is working against CONFIG_NO_HZ,
| and powertop should show lots of wakeups and hopefully give hints who is
| guilty.
|
| Do you have any other USB 1.1 devices (for example a USB missile
| launcher, that thing *is* cheap china crap) that might send data at a
| rate of 1kHz? You could look at the output of lsusb.
|
| Regards,
|   Michael Karcher

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