On Thursday, August 16, 2012 09:20:55 PM Johannes Berg wrote: > On Thu, 2012-08-09 at 21:43 +0200, Christian Lamparter wrote: > > On Thursday, August 09, 2012 06:54:34 PM Marco Fonseca wrote: > > > Hello All, > > > > > > I've noticed unexpected transmissions from the AR9170 while in monitor mode > > > and using tcpdump (and sometimes without tcpdump running). These > > > transmissions degrade (pretty significantly) performance of other STA/AP on > > > the channel (as seen by iperf going from 60mbit/s to almost nill). As best I > > > can tell these transmissions never coalesces into an actual frame in the air > > > (at least not one I'm able to pick up with a second different adapter in > > > monitor mode). > > > > > > Are there any known reasons/bugs on this? Is there anyway to completely > > > silence the transmitter of the AR9170 while still allowing reception? > > > > > yes. <http://www.spinics.net/lists/linux-wireless/msg88896.html> > > > > a solution is described in: > > <http://www.spinics.net/lists/linux-wireless/msg89279.html> > > > > (iw dev wlanX set monitor none - if I'm not mistaken) > > I've seen this before too -- what flag causes the issue, and why? Well that would be: FIF_OTHER_BSS or FIF_PROMISC_IN_BSS either one of these will set following flags for the hardware: AR9170_MAC_RX_CTRL_ACK_IN_SNIFFER AR9170_MAC_SNIFFER_ENABLE_PROMISC About the issue, I'm really can't tell w/o schematics of the hardware. It could be that ACK_IN_SNIFFER is more of a debug/test flag than a real feature? (Anyway, I cc'd Stephen. Maybe he knows more) Regards, Chr -- 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
