[PATCH ath-next v2 2/2] wifi: ath11k: do not fail down transitions of the station state

[Julius Bairaktaris <julius@bairaktaris.de>]

mac80211 requires sta_state to succeed for down transitions and warns
when the driver returns an error for one. ath11k returns the result of
WMI commands for ASSOC -> AUTH and NONE -> NOTEXIST, and these fail
with -ESHUTDOWN while the firmware is down. A station removed during a
firmware crash then triggers, for the disassociation:

  Driver is not allowed to fail if the sta_state is transitioning down the list: -108
  WARNING: CPU: 1 PID: 5952 at net/mac80211/sta_info.c:1561 ieee80211_sta_eosp+0x119c/0x1668 [mac80211]

and for the removal:

  WARNING: CPU: 2 PID: 2080 at net/mac80211/sta_info.c:1652 sta_set_sinfo+0x1118/0x1144 [mac80211]
  Call trace:
   sta_set_sinfo+0x1118/0x1144 [mac80211] (P)
   sta_info_destroy_addr_bss+0x34/0x48 [mac80211]
   ieee80211_del_station+0x1c/0x54 [mac80211]
   nl80211_del_station+0xf4/0x174 [cfg80211]

Two of these failures also skip host cleanup. On a non-AP vdev of a
device with vdev_start_delay, a failed early vdev stop returns from
ath11k_mac_station_remove() before the DP peer cleanup and the station
accounting, and ath11k_mac_op_sta_state() then frees the peer with its
rx_tid state still in place. For a non-WME station, a failed RTS/CTS
update returns from ath11k_station_disassoc() before the peer keys are
cleared.

Warn and carry on with the host cleanup in both, and return success for
every down transition.

Tested-on: IPQ8074 hw2.0 AHB WLAN.HK.2.12-01460

Fixes: d5c65159f289 ("ath11k: driver for Qualcomm IEEE 802.11ax devices")
Signed-off-by: Julius Bairaktaris <julius@bairaktaris.de>
---
Changes in v2: continue the host cleanup after a failed early vdev stop and a
failed RTS/CTS update instead of returning from them.

 drivers/net/wireless/ath/ath11k/mac.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/net/wireless/ath/ath11k/mac.c b/drivers/net/wireless/ath/ath11k/mac.c
index 9c3f577c9562..a86d1b6c0d73 100644
--- a/drivers/net/wireless/ath/ath11k/mac.c
+++ b/drivers/net/wireless/ath/ath11k/mac.c
@@ -4984,9 +4984,7 @@ static int ath11k_station_disassoc(struct ath11k *ar,
 
 	if (!sta->wme) {
 		arvif->num_legacy_stations--;
-		ret = ath11k_recalc_rtscts_prot(arvif);
-		if (ret)
-			return ret;
+		ath11k_recalc_rtscts_prot(arvif);
 	}
 
 	ret = ath11k_clear_peer_keys(arvif, sta->addr);
@@ -9922,10 +9920,8 @@ static int ath11k_mac_station_remove(struct ath11k *ar,
 	    arvif->is_started &&
 	    arvif->vdev_type != WMI_VDEV_TYPE_AP) {
 		ret = ath11k_mac_stop_vdev_early(ar->hw, vif);
-		if (ret) {
+		if (ret)
 			ath11k_warn(ab, "failed to do early vdev stop: %d\n", ret);
-			return ret;
-		}
 	}
 
 	ath11k_dp_peer_cleanup(ar, arvif->vdev_id, sta->addr);
@@ -10079,6 +10075,10 @@ static int ath11k_mac_op_sta_state(struct ieee80211_hw *hw,
 				    sta->addr);
 	}
 
+	/* mac80211 does not let a down transition fail */
+	if (new_state < old_state)
+		ret = 0;
+
 	mutex_unlock(&ar->conf_mutex);
 	return ret;
 }
-- 
2.53.0