I'm trying to do some antenna work so I want a weak signal from the
other side of the basement. So I try stuff like ifconfig athn0
txpower 1 and get "ifconfig: SIOCS80211TXPOWER: Invalid argument".
Any number I've tried gives the same thing. If I leave out the number
it tells me I need one. Worse, the same thing happens with athn, ath,
urtwn, in OpenBSD 5.6, 5.2, 5.0. Looking in ieee80211_ioctl.h the
power (dBm) value is an int16_t but there's also an i_mode int which
controls whether the value can be set manually or it's in automatic
mode. The ifconfig man page says:
txpower dBm
Set the transmit power. The driver will disable any auto level
and transmit power controls in this mode.
Implying that setting txpower should work. It seems stuck in auto
mode or something. I've Googled this and other people have had
similar problems for years but no solution seems to be posted.
Using -txpower which should (by the man page) put it back in auto mode
gives the same invalid argument error. It seems to be something wrong
with ifconfig since it works the same way with 3 different cards, or
it's something wrong in the man page so I'm using it wrong. I'm
probably the only one who wants to turn the power down. I should
probably stick in a printf to see exactly what's being fed to the
ioctl. Or something in setiftxpower() in ifconfig.c
Alan
--
Credit is the root of all evil. - AB1JX
