Global txpower in ath

[Sam Pierson]

I noticed that when I control the signal strength through
ifconfig, I can effectively reduce the signal when I set it
as something like:  ifconfig ath0 txpower 1.  I have read
that this input is device driver dependent and I couldn't
find anything in the interface that handles txcontrol.  Are
these values taken in exactly or are they rounded to some
less fine-grained control number?  Thanks,

Sam