From owner-freebsd-bugs@FreeBSD.ORG Tue Jul 31 23:50:10 2012 Return-Path: Delivered-To: freebsd-bugs@hub.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 40A5E1065672 for ; Tue, 31 Jul 2012 23:50:10 +0000 (UTC) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (freefall.freebsd.org [IPv6:2001:4f8:fff6::28]) by mx1.freebsd.org (Postfix) with ESMTP id 19A258FC12 for ; Tue, 31 Jul 2012 23:50:10 +0000 (UTC) Received: from freefall.freebsd.org (localhost [127.0.0.1]) by freefall.freebsd.org (8.14.5/8.14.5) with ESMTP id q6VNo9lp003710 for ; Tue, 31 Jul 2012 23:50:09 GMT (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.14.5/8.14.5/Submit) id q6VNo9kb003709; Tue, 31 Jul 2012 23:50:09 GMT (envelope-from gnats) Resent-Date: Tue, 31 Jul 2012 23:50:09 GMT Resent-Message-Id: <201207312350.q6VNo9kb003709@freefall.freebsd.org> Resent-From: FreeBSD-gnats-submit@FreeBSD.org (GNATS Filer) Resent-To: freebsd-bugs@FreeBSD.org Resent-Reply-To: FreeBSD-gnats-submit@FreeBSD.org, Adrian Chadd Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 915C0106566C for ; Tue, 31 Jul 2012 23:47:15 +0000 (UTC) (envelope-from nobody@FreeBSD.org) Received: from red.freebsd.org (red.freebsd.org [IPv6:2001:4f8:fff6::22]) by mx1.freebsd.org (Postfix) with ESMTP id 7D3148FC14 for ; Tue, 31 Jul 2012 23:47:15 +0000 (UTC) Received: from red.freebsd.org (localhost [127.0.0.1]) by red.freebsd.org (8.14.4/8.14.4) with ESMTP id q6VNlFE8097445 for ; Tue, 31 Jul 2012 23:47:15 GMT (envelope-from nobody@red.freebsd.org) Received: (from nobody@localhost) by red.freebsd.org (8.14.4/8.14.4/Submit) id q6VNlFV6097444; Tue, 31 Jul 2012 23:47:15 GMT (envelope-from nobody) Message-Id: <201207312347.q6VNlFV6097444@red.freebsd.org> Date: Tue, 31 Jul 2012 23:47:15 GMT From: Adrian Chadd To: freebsd-gnats-submit@FreeBSD.org X-Send-Pr-Version: www-3.1 Cc: Subject: misc/170302: [ath] 802.11n frames are not being transmitted with multiple rates X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 31 Jul 2012 23:50:10 -0000 >Number: 170302 >Category: misc >Synopsis: [ath] 802.11n frames are not being transmitted with multiple rates >Confidential: no >Severity: non-critical >Priority: low >Responsible: freebsd-bugs >State: open >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Tue Jul 31 23:50:09 UTC 2012 >Closed-Date: >Last-Modified: >Originator: Adrian Chadd >Release: 9.0-STABLE i386, with -HEAD net80211/ath >Organization: >Environment: FreeBSD marilyn 9.0-STABLE FreeBSD 9.0-STABLE #6 r238210M: Sat Jul 21 16:59:42 PDT 2012 adrian@marilyn:/home/adrian/work/freebsd/stable/9/sys/i386/compile/MARILYN-9-STABLE i386 >Description: When doing some debugging, I noticed that the rate control code is not transmitting frames with multiple rate retries. For example, with 'sysctl dev.ath.0.debug=2' set (TX descriptor debugging): Q1[ 0] (DS.V:0xea739000 DS.P:0x1d29c000) L:00000000 D:3958d82c F:0005 Seq: 1904 swtry: 0 ADDBAW?: 0 DOBAW?: 0 417f0242 00008240 00048000 0000008f 0000803a 00000000 00000000 0090000f 00000000 3f000000 3f000000 3f000000 0080292c 00000101 4ccfdabf ffffffff ffffffff 2d80282a 80808080 80808080 80808080 0000056b [end] Q1[ 0] (DS.V:0xea739000 DS.P:0x1d29c000) L:00000000 D:3958d82c F:0005 * Seq: 1904 swtry: 0 ADDBAW?: 0 DOBAW?: 0 417f0242 00008240 00048000 0000008f 0000803a 00000000 00000000 0090000f 00000000 3f000000 3f000000 3f000000 0080292c 00000101 4ccfdabf ffffffff ffffffff 2d80282a 80808080 80808080 80808080 0000056b [end] . descriptor field 3 is 0x8f, which shows only one 11n rate (rate attempt #0) is set. >How-To-Repeat: associate to an 802.11n AP. >Fix: The TX and rate control paths assume that if RTS/CTS is enabled, multi-rate retry should be disabled. This is because of a limitation with the pre-11n chips - the AR5212 supports multi-rate retry but not with RTS/CTS enabled. >Release-Note: >Audit-Trail: >Unformatted: