[ltp] Locking up when line power failure

[John Jason Jordan]

Thinkpad T61, Hardy x86_64, up to date, everything works that I care to
have work. 

I live in a city so electric power is pretty reliable. Nevertheless,
two or three times a year there will be a momentary loss - sufficient
to kill my desktop computer, but the lights merely flicker off and back
on.

My T61 lives at home 95% of the time, where it is plugged into a
docking station. The battery is always fully charged, unless I have
just returned from school or someplace where I used it on battery power
alone. 

Yesterday I returned home to find that the T61 was locked up and the
desktop computer and the stereo turned off. Everything else in the
house was running fine. As I said, this has happened before. It is no
big deal to turn the stereo back on and reboot the desktop computer.
For that matter, rebooting the T61 is not a big deal either, as I never
leave either computer with unsaved work. 

However, why does the T61 lock up? When the line power goes out it
should just switch to battery, and when the line power is restored it
should just switch back to line power and recharge the battery as
necessary. There should be no effect on the running condition of the
computer. Indeed, the computer is still running. The wireless and
bluetooth lights are lit up and when I move my bluetooth mouse the
bluetooth light flickers a bit as it always does when I move the mouse.
But the screen is black and nothing I can do will get it back -
Ctrl-Alt-F1 does not work, nor does Ctrl-Alt-Backspace. Yesterday I did
manage to get Ctrl-Alt-F1 to get me to a command line by waiting a long
time, but Ctrl-Alt-F7 just took me back to a black screen.

A brief loss of mains power should not cause any problems. Does anyone
have any comments or suggestions?