From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from he.sipsolutions.net ([78.46.109.217]:42493 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751586Ab1J1JQC (ORCPT ); Fri, 28 Oct 2011 05:16:02 -0400 Subject: RE: [RFC v2 13/12] cfg80211/mac80211: allow management TX to not wait for ACK From: Johannes Berg To: Arend Van Spriel Cc: Helmut Schaa , "linux-wireless@vger.kernel.org" In-Reply-To: <400C43189542CE41BC0A5B252FC90136BC0E375417@SJEXCHCCR02.corp.ad.broadcom.com> References: <20111021142322.229128720@sipsolutions.net> <1319743973.32221.4.camel@jlt3.sipsolutions.net> <400C43189542CE41BC0A5B252FC90136BC0E3753AA@SJEXCHCCR02.corp.ad.broadcom.com> <400C43189542CE41BC0A5B252FC90136BC0E375417@SJEXCHCCR02.corp.ad.broadcom.com> Content-Type: text/plain; charset="UTF-8" Date: Fri, 28 Oct 2011 11:15:55 +0200 Message-ID: <1319793355.8931.4.camel@jlt3.sipsolutions.net> (sfid-20111028_111607_341374_1D21C1F9) Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Fri, 2011-10-28 at 02:07 -0700, Arend Van Spriel wrote: > > From: Helmut Schaa [mailto:helmut.schaa@googlemail.com] > > Sent: vrijdag 28 oktober 2011 9:52 > > > > On Fri, Oct 28, 2011 at 9:48 AM, Arend Van Spriel > > wrote: > > > I would expect this to affect the duration field in the > > > 802.11 header to indicate the shorter use of the medium. > > > Going through your patch I am not sure this is done. > > > > I don't think so since the frame will still be acked by the peer as it > > is > > a unicast management frame. But this will advise the hardware that it > > does not need to wait for the ack to happen since we're not interested > > in retrying it. > I understand. However, the commit message of this patch suggests we are > saving airtime, which does not seem the case if the duration field is > not taken into account. If the ACK is still transmitted we should not > touch the duration field so I guess my comment is only on the commit > message itself. Oh good points ... The reason we save airtime is that often the frame will be retransmitted a lot if the station is no longer paying attention. johannes