Hi,
Please check if the attached patch helps
If it does not, please open bug report at bugzilla.kernel.org against ACPI/EC.

Regards,
Alex.
Florian Zumbiehl пишет:
> Hi,
> 
> I have here a T20 thinkpad with a T22 BIOS and a 2.6.32 kernel. After
> boot, acpi_listen shows me all the events that are being generated by
> the lid switch, hotkeys, batteries, ac, and maybe more. However,
> when I disconnect and reconnect ac power a few times in rapid
> succession, that leads to all of these events not being reported
> anymore. Suspend to RAM and to disk both don't fix it, only a
> reboot does.
> 
> After I posted this on the thinkpad-acpi mailing list, I was told
> that this probably was a problem with the EC (driver|firmware),
> so that's why I am addressing this to you now :-)
> 
> The BIOS and EC firmware are the newest versions available
> (1.12 and 1.06, respectively).
> 
> Any hints as to how to debug or possibly even fix this would be
> appreciated.
> 
> Florian