Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755809AbbDUQ30 (ORCPT ); Tue, 21 Apr 2015 12:29:26 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:57080 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755552AbbDUPch (ORCPT ); Tue, 21 Apr 2015 11:32:37 -0400 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Michal Kazior , Johannes Berg , Luis Henriques Subject: [PATCH 3.16.y-ckt 010/144] mac80211: disable u-APSD queues by default Date: Tue, 21 Apr 2015 16:29:55 +0100 Message-Id: <1429630329-21748-11-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1429630329-21748-1-git-send-email-luis.henriques@canonical.com> References: <1429630329-21748-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3110 Lines: 78 3.16.7-ckt10 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Michal Kazior commit aa75ebc275b2a91b193654a177daf900ad6703f0 upstream. Some APs experience problems when working with U-APSD. Decreasing the probability of that happening by using legacy mode for all ACs but VO isn't enough. Cisco 4410N originally forced us to enable VO by default only because it treated non-VO ACs as legacy. However some APs (notably Netgear R7000) silently reclassify packets to different ACs. Since u-APSD ACs require trigger frames for frame retrieval clients would never see some frames (e.g. ARP responses) or would fetch them accidentally after a long time. It makes little sense to enable u-APSD queues by default because it needs userspace applications to be aware of it to actually take advantage of the possible additional powersavings. Implicitly depending on driver autotrigger frame support doesn't make much sense. Signed-off-by: Michal Kazior Signed-off-by: Johannes Berg Signed-off-by: Luis Henriques --- net/mac80211/ieee80211_i.h | 23 +++++++++++++++++------ 1 file changed, 17 insertions(+), 6 deletions(-) diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index 5ed8c78d6f68..6b943c29937b 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -57,13 +57,24 @@ struct ieee80211_local; #define IEEE80211_UNSET_POWER_LEVEL INT_MIN /* - * Some APs experience problems when working with U-APSD. Decrease the - * probability of that happening by using legacy mode for all ACs but VO. - * The AP that caused us trouble was a Cisco 4410N. It ignores our - * setting, and always treats non-VO ACs as legacy. + * Some APs experience problems when working with U-APSD. Decreasing the + * probability of that happening by using legacy mode for all ACs but VO isn't + * enough. + * + * Cisco 4410N originally forced us to enable VO by default only because it + * treated non-VO ACs as legacy. + * + * However some APs (notably Netgear R7000) silently reclassify packets to + * different ACs. Since u-APSD ACs require trigger frames for frame retrieval + * clients would never see some frames (e.g. ARP responses) or would fetch them + * accidentally after a long time. + * + * It makes little sense to enable u-APSD queues by default because it needs + * userspace applications to be aware of it to actually take advantage of the + * possible additional powersavings. Implicitly depending on driver autotrigger + * frame support doesn't make much sense. */ -#define IEEE80211_DEFAULT_UAPSD_QUEUES \ - IEEE80211_WMM_IE_STA_QOSINFO_AC_VO +#define IEEE80211_DEFAULT_UAPSD_QUEUES 0 #define IEEE80211_DEFAULT_MAX_SP_LEN \ IEEE80211_WMM_IE_STA_QOSINFO_SP_ALL -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/