[ltp] very high number of wakeups (and power consumption) on T60p

[Peter F. Patel-Schneider]

From: Theodore Tso <tytso@MIT.EDU>
Subject: Re: [ltp] very high number of wakeups (and power consumption) on T60p
Date: Wed, 27 Feb 2008 20:09:06 -0500

> On Wed, Feb 27, 2008 at 07:46:10PM -0500, Peter F. Patel-Schneider wrote:
> > Has anyone run into problems with tens of thousands of wakeups that are
> > unexplained in powertop?  This does appear to be real as battery drain
> > does jump up about 30-40%.
> 
> There was a bug that was fixed in a very recent BIOS release for most
> Thinkpad which caused interrupts to go wild if bluetooth was enabled
> and the usb modules were loaded.  You might want to try updating your
> BIOS to the very latest firmware and see if the problem goes away.
> Another workaround if you can't upgrade your firmware right away is to
> disable bluetooth using "echo disable > /proc/acpi/ibm/bluetooth".  
> 
> If you depend on the Bluetooth interface, then your only option will
> be to upgrade your BIOS.  :-0
> 
> 						- Ted

This is not likely to be my problem, but thanks for the information.

I updated to the current BIOS (2.20 for T60p) and the problem persists.

Following /proc/interrupts doesn't lead to any culprits either.  Only
about 100 interrupts per second are shown there, whereas I'm currently
getting over 41 thousand wakeups-from-idle per second.

I guess that this leaves DMA activity as the prime suspect, even though
I have the radios (WiFi and bluetooth) switched off.

peter