Return-path: Received: from mail-pz0-f46.google.com ([209.85.210.46]:58375 "EHLO mail-pz0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751997Ab1LSNH6 convert rfc822-to-8bit (ORCPT ); Mon, 19 Dec 2011 08:07:58 -0500 Received: by dajs34 with SMTP id s34so3420449daj.19 for ; Mon, 19 Dec 2011 05:07:57 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <20111219112845.C748820066@mail.watchdata.com.cn> References: <4EED232D.3010208@lwfinger.net> <20111219112845.C748820066@mail.watchdata.com.cn> Date: Mon, 19 Dec 2011 14:07:56 +0100 Message-ID: (sfid-20111219_140800_882526_F4A38B26) Subject: Re: Question about IEEE80211_TX_CTL_NO_ACK in ath_9k From: Helmut Schaa To: =?GB2312?B?wO641Q==?= Cc: wireless Content-Type: text/plain; charset=GB2312 Sender: linux-wireless-owner@vger.kernel.org List-ID: 2011/12/19 ???? : > My wireless card is AR9280. I set the IEEE80211_TX_CTL_NO_ACK flag before > send a packet, but found it no use. It still wait for an ACK. How did you verify that? For unicast frames with IEEE80211_TX_CTL_NO_ACK set you will still see an ACK on the air (since the peer has to generate it according to the 802.11 spec). The only thing this flag does is to advise the hardware to ignore a missing ACK and hence to not retry the frame in this case ... Helmut