I have two questions. 1. As a result of debugging 'ath10k' and 'mac80211', if there is a problem, ADDBA request and DELBA request are receive at 'station' side at the same time. Could it be this? 2. The code below seems to fix the problem. (I did not consider the impact elsewhere.) Is it the correct code? How do I fix the incorrect code? --- net/mac80211/iface.c +++ net/mac80211/iface.c @@ -1260,10 +1265,14 @@ mutex_lock(&local->sta_mtx); sta = sta_info_get_bss(sdata, rx_agg->addr); if (sta) + { +/* __ieee80211_stop_rx_ba_session(sta, rx_agg->tid, WLAN_BACK_RECIPIENT, 0, false); + */ + } mutex_unlock(&local->sta_mtx); } else if (ieee80211_is_action(mgmt->frame_control) && mgmt->u.action.category == WLAN_CATEGORY_BACK) { --------------- Kim Kwang Min Mobile +82 010-5521-6393 Mail gwondori@nimbus.kr -----Original Message----- From: "Kwang Min Kim" To: "Adrian Chadd"; ; Cc: Sent: 2017-01-19 (목) 19:26:44 Subject: Re: All '0' in agg_status hi, adrian firmware: 10.2.4.59-2 chipset: qca9880 driver version: backports-4.4.2 Thanks. --------------- Kim Kwang Min Mobile +82 010-5521-6393 Mail gwondori@nimbus.kr -----Original Message----- From: "Adrian Chadd" To: "김광민"; Cc: "ath10k@lists.infradead.org"; "강경완"; Sent: 2017-01-18 (수) 16:40:26 Subject: Re: All '0' in agg_status hiya which firmware, chipset, driver version is this with? -adrian -----Original Message----- From: "김광민" To: ; Cc: "강경완"; Sent: 2017-01-17 (화) 20:30:22 Subject: All '0' in agg_status Very rarely, I experience the problem that packets are serious dropped even though all wireless states(iwconfig, iw wlan0 info, fw_stats, etc.) are OK. This problem occurs only after the AP and station are badly(?) connected, and once the connection is established normally, this problem does not occur on the good connection. And once this problem occurred, it won't be fixed by itself until the AP and the station are reconnected. I have investigated and I have found two differences between the good connection and the bad connection. The one is the error messages on dmesg, <...> [ 2826.432784] wlan0: Limiting TX power to 21 (24 - 3) dBm as advertised by 04:f0:21:20:38:09 [ 2827.296925] wlan0: Rx A-MPDU request on 04:f0:21:20:38:09 tid 0 result 0 [ 2827.297483] wlan0: Rx BA session stop requested for 04:f0:21:20:38:09 tid 0 recipient reason: 0 <--- from this line [ 2827.297578] wlan0: Rx A-MPDU request on 04:f0:21:20:38:09 tid 0 result 0 [ 2827.298694] wlan0: Rx BA session stop requested for 04:f0:21:20:38:09 tid 0 recipient reason: 0 [ 2829.074439] wlan0: Rx A-MPDU request on 04:f0:21:20:38:09 tid 6 result 0 <-- to this line <...> The another difference is in "agg_status" file on Station side (/sys/kernel/debug/ieee80211/phy0/netdev:wlan0/stations/XX:XX:XX:XX:XX:XX/agg_status). As my investigation, the file of the AP side always have one or two '1' at the second column. And the file of the station side without problem also have one or two '1'. But, there is no '1' in the file on the station where the problem occurred. #more /sys/kernel/debug/ieee80211/phy0/netdev\:wlan0/stations/*/agg_status next dialog_token: 0x1 TID RX DTKN SSN TX DTKN pending 00 0 0x00 0x000 0 0x00 000 01 0 0x00 0x000 0 0x00 000 02 0 0x00 0x000 0 0x00 000 03 0 0x00 0x000 0 0x00 000 04 0 0x00 0x000 0 0x00 000 05 0 0x00 0x000 0 0x00 000 06 0 0x00 0x000 0 0x00 000 07 0 0x00 0x000 0 0x00 000 08 0 0x00 0x000 0 0x00 000 09 0 0x00 0x000 0 0x00 000 10 0 0x00 0x000 0 0x00 000 11 0 0x00 0x000 0 0x00 000 12 0 0x00 0x000 0 0x00 000 13 0 0x00 0x000 0 0x00 000 14 0 0x00 0x000 0 0x00 000 15 0 0x00 0x000 0 0x00 000 Could you tell me what I have to do? Should one more '1' exist at the second columns of "agg_status"? In other words, is it problem if there is no '1' in the second column of agg_status? If you know how to fix this, please let me know that. --------------- Kim Kwang Min Mobile +82 010-5521-6393 Mail gwondori@nimbus.kr