[ltp] Re: Fingerprint Reader -> USB -> no C3

[Florian Reitmeir]

On Mon, 25 Feb 2008, Rolf Kutz wrote:

> On 25/02/08 10:57 +0100, Florian Reitmeir wrote:
>> On Sun, 24 Feb 2008, Stefan Monnier wrote:
>>> > hw.thinkpad_fingerprint true -> disable the reader
>>> > hw.thinkpad_fingerprint false -> enable the reader
>>> Thanks: now I got my T60 down to 13W again!  It makes a 2W difference
>>> almost.  But in my case (Debian stock 2.6.23 kernel) putting it in
>>> "auto" works as well as putting it in "suspend".  Don't know why it
>>> isn't in "auto" in the first place since all the USB power settings in
>>> the /sys files seem to indicate that it's all in "autosuspend" mode.
>>
>> the problem is, the kernel people did change the autosuspend policy in the
>> kernel .. while the core usb is autosuspend enabled, IMHO the devices are now
>> on a white/backlist for autosuspend (i didn't look into the kernel code)
>>
>> i did notice the problem because every time regardless of my config powertop
>> suggested to "enable autosuspend" for usb.. and after applying the CPU did C3
>> again... and i really do not need the reader :-)
>
> What version of Powertop? 1.8 hat a bug that
> caused this.

always the latest of debian/unstable, but the bug is not a powertop bug, its
a kernel change.

here in my 2.6.24.x kernel, after every resume from STR i need to disable the
device.. again. 

-- 
Florian Reitmeir