On Fri, Aug 05, 2011 at 08:24:53AM +0530, Rajkumar Manoharan wrote: > On Thu, Aug 04, 2011 at 08:23:28PM +0200, Felix Fietkau wrote: > > On 2011-08-04 7:54 PM, Rajkumar Manoharan wrote: > > >The Walsh bit is disabled for regulatory consideration. > > > > > >As per the FCC rulings, only transmissions that are completely > > >non-coherent, are allowed to waive the array gain contribution > > >to EIRP for multi-transmit configurations. The use of 2-stream > > >with 2 transmit and use of 3-steam with 3 transmit qualifies > > >for this spatial multiplexing MIMO classification as long as > > >the streams are directly mapped to each radio (not Walsh spread > > >prior to splitting to multiple radios) > > I think ath9k does not waive the array gain contribution. I haven't > > checked AR9003, but on AR9002 and older, it explicitly includes the > > array gain contribution in the tx power limit calculation. I'm not > > sure that unconditionally disabling spatial spreading is the right > > way to deal with this. > > > We might violate the FCC rule with 2x2 config(3dB higher at 2-stream) > if this bit is enabled. Based on chainmask we can disable Walsh bit. This change does not affect 3x3, since we don't use 2-chain for 2-stream. And Walsh mode would follow INI setting for 2x2 or 3x3 config. -- Rajkumar -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
