mac80211: fix spurious disconnections with powersave clients

Affects all drivers using ieee80211_tx_status_noskb, e.g. ath9k and mt76

Signed-off-by: Felix Fietkau <nbd@nbd.name>

package/kernel/mac80211/patches/subsys/379-mac80211-ignore-tx-status-for-PS-stations-in-ieee802.patch

@@ -0,0 +1,26 @@
+From: Felix Fietkau <nbd@nbd.name>
+Date: Tue, 13 Nov 2018 20:29:03 +0100
+Subject: [PATCH] mac80211: ignore tx status for PS stations in
+ ieee80211_tx_status_ext
+
+Make it behave like regular ieee80211_tx_status calls, except for the lack of
+filtered frame processing.
+This fixes spurious low-ack triggered disconnections with powersave clients
+connected to an AP.
+
+Fixes: f027c2aca0cf4 ("mac80211: add ieee80211_tx_status_noskb")
+Cc: stable@vger.kernel.org
+Signed-off-by: Felix Fietkau <nbd@nbd.name>
+---
+
+--- a/net/mac80211/status.c
++++ b/net/mac80211/status.c
+@@ -987,6 +987,8 @@ void ieee80211_tx_status_ext(struct ieee
+ 			/* Track when last TDLS packet was ACKed */
+ 			if (test_sta_flag(sta, WLAN_STA_TDLS_PEER_AUTH))
+ 				sta->status_stats.last_tdls_pkt_time = jiffies;
++		} else if (test_sta_flag(sta, WLAN_STA_PS_STA)) {
++			return;
+ 		} else {
+ 			ieee80211_lost_packet(sta, info);
+ 		}