Return-path: Received: from nbd.name ([46.4.11.11]:39581 "EHLO nbd.name" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161930Ab3DEQPO (ORCPT ); Fri, 5 Apr 2013 12:15:14 -0400 Message-ID: <515EF88F.1030606@openwrt.org> (sfid-20130405_181519_333203_817F1045) Date: Fri, 05 Apr 2013 18:15:11 +0200 From: Felix Fietkau MIME-Version: 1.0 To: Harshal Chhaya CC: linux-wireless Subject: Re: AR9342: Two odd packets in every beacon interval in 5Ghz References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-wireless-owner@vger.kernel.org List-ID: On 2013-04-05 5:24 PM, Harshal Chhaya wrote: > Hello, > > We have an AR9342-based AP that is sending out two odd packets each > beacon interval. These packets are 1804 bytes in size, are transmitted > at 6.5Mbps and have the dest MAC address the same as the source MAC > address. > > The payload of these packets is all zeros. > > It does this only in 5Ghz. These packets aren't transmitted in the 2.4Ghz band. > > If we set the bandwidth to 40MHz, it sends only one of these packets > between beacons. > > Are these some control or mgmt packets that are part of the protocol? > Or is this unexpected behavior? > > The AP is running the 3.3.8 kernel and a compat-wireless from Sep 2012 > (part of the openwrt image for this chip). Maybe it's (failing) PA predistortion calibration, which needs to send training frames to complete. I'd suggest trying a newer compat-wireless version, this type of calibration has been disabled there because of various issues (including hardware damage on some chips). - Felix