Setting txpower above the power of your card
msmith at cbnco.com
Wed Oct 23 15:48:49 EDT 2002
On Sun, 20 Oct 2002, Scott Stapleton wrote:
> I then thought I'd try setting it to 150mW to see what happened. I never
> expected it to increase, but it did somewhat.
I was curious (I've been setting my txpower to 200 for months now, on
cards that only do 23 dBm :) so I did a quick grep and it looks like the
driver scales the value supplied by the user, in the range -43 to 20, to
the minimum and maximum values supported by the hardware.
current mapping: minimum power with 'iwconfig wlan0 txpower -43'
and maximum with 'iwconfig wlan0 txpower 20'
static u16 prism2_txpower_dBm_to_hfa386x(int val)
signed char tmp;
if (val > 20)
else if (val < -43)
tmp = val;
tmp = -12 - tmp;
tmp <<= 2;
return (unsigned char) tmp;
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