mac80211: disable u-APSD queues by default (aa75ebc2) · Commits · 戴 / test

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. Cc: stable@vger.kernel.org Signed-off-by:

Michal Kazior <michal.kazior@tieto.com> Signed-off-by:

Johannes Berg <johannes.berg@intel.com>

net/mac80211/ieee80211_i.h

+17 −6

Original line number	Diff line number	Diff line
		@@ -58,13 +58,24 @@ 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

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