From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755969Ab2HMWTO (ORCPT ); Mon, 13 Aug 2012 18:19:14 -0400 Received: from mail-yx0-f174.google.com ([209.85.213.174]:46692 "EHLO mail-yx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755908Ab2HMWTI (ORCPT ); Mon, 13 Aug 2012 18:19:08 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg KH , torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Emmanuel Grumbach , Cesar Eduardo Barros , Johannes Berg , "John W. Linville" Subject: [ 61/65] iwlwifi: disable greenfield transmissions as a workaround Date: Mon, 13 Aug 2012 15:14:45 -0700 Message-Id: <20120813221420.378571191@linuxfoundation.org> X-Mailer: git-send-email 1.7.10.1.362.g242cab3 In-Reply-To: <20120813221414.965154048@linuxfoundation.org> References: <20120813221414.965154048@linuxfoundation.org> User-Agent: quilt/0.60-20.5 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Greg KH 3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Johannes Berg commit 50e2a30cf6fcaeb2d27360ba614dd169a10041c5 upstream. There's a bug that causes the rate scaling to get stuck when it has to use single-stream rates with a peer that can do GF and SGI; the two are incompatible so we can't use them together, but that causes the algorithm to not work at all, it always rejects updates. Disable greenfield for now to prevent that problem. Reviewed-by: Emmanuel Grumbach Tested-by: Cesar Eduardo Barros Signed-off-by: Johannes Berg Signed-off-by: John W. Linville Signed-off-by: Greg Kroah-Hartman --- drivers/net/wireless/iwlwifi/iwl-agn-rs.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) --- a/drivers/net/wireless/iwlwifi/iwl-agn-rs.c +++ b/drivers/net/wireless/iwlwifi/iwl-agn-rs.c @@ -709,11 +709,14 @@ static int rs_toggle_antenna(u32 valid_a */ static bool rs_use_green(struct ieee80211_sta *sta) { - struct iwl_station_priv *sta_priv = (void *)sta->drv_priv; - struct iwl_rxon_context *ctx = sta_priv->ctx; - - return (sta->ht_cap.cap & IEEE80211_HT_CAP_GRN_FLD) && - !(ctx->ht.non_gf_sta_present); + /* + * There's a bug somewhere in this code that causes the + * scaling to get stuck because GF+SGI can't be combined + * in SISO rates. Until we find that bug, disable GF, it + * has only limited benefit and we still interoperate with + * GF APs since we can always receive GF transmissions. + */ + return false; } /**