[ltp] undervolted T43 does not resume from suspend-to-ram when on battery

[fire-eyes]

Marcus Obst wrote:
> Hi,
> 
> two weeks age I undervolted my T43 with the unmodified example kernel
> patch (Alternative 1) provieded by
> 
>     http://thinkwiki.org/wiki/Pentium_M_undervolting_and_underclocking
> 
> My system used to run quite stable even under high load (it survived
> multiple kernel and QT4 compilations).
> 
> Also the other promised featuers are working:
>     - high pitch noise gone
>     - battery life prolonged
>     - cpu temperature decreasd, especially with high load
>       (15K less then before)
> 
> Yesterday I tried to wake up my Thinkpad from suspend-to-disk without
> AC connected . 
> The system came up but screen remained still blank.  Only the ACPI event
> for the power button was generated, so I could reboot.
> 
> After reboot (still running on battery) system came up but showed
> strange error messages about wrong cpu frequency settings.
> I inspected /proc/cpuinfo and found a crooked frequency value.  It was
> about 377MHz (normally it is the default max value of 1862MHz).
> Frequency scaling was not activated at this time.
> 
> Then I plugged in AC and rebooted, everything was fine again.
> 
> -> It is a reproduceable problem which only happens if laptop is on
>    battery.
> 
> Anybody seen this before, ideas?
> 
>     Best regards from Chemnitz/Germany!
>     Marcus Obst
> 

Interesting. First off, you DID have suspend to ram working? I have
suspending working, but coming back is a different matter, the disk
drive won't wake up. And I see the same thing you describe, except for
the stuff about frequencies and what not. I just have to hard power
down. Basically I can't  use it.