Re: carl9170 driver - reducing the output power

[Christian Lamparter <chunkeey@googlemail.com>]

On Tuesday, June 26, 2012 02:10:25 PM Michal Kudelski wrote:
> Thank you for the response! Indeed, when I used the latest 
> compat-wireless, I was able to control the output power.

I'm glad I could help.
 
> Now, another question arises: what is the lowest supported 
> power level? Do you have any hardware specifications of 
> AR9170 that would say what is the lowest power level 
> supported by the hardware?

No, I'm sorry, but I don't have such a thing (Maybe Adrian
knows more). From what I knot, the lowest possible value
for the "tpc" registers and the tx descriptor tpc is "0"
(there's no "sign" bit so I'm afraid anything lower than
0 is not possible).
 
> With iw/iwconfig commands, the lowest achievable power is 
> 1 dbm. But I'm thinking about modifying your code in order 
> to write fixed values to the corresponding registers. And 
> I need to know what to write into the registers in order 
> to obtain the lowest possible power :-) .

The power is set by:
carl9170_tx_rate_tpc_chains in tx.c (for most outgoing frame -
except control frames like ACKs/ERP/... which are
controlled by carl9170_set_mac_tpc in mac.c)

Regards,
	Christian