From d673cb6fe6c03b2be157cc6c5db40481828d282d Mon Sep 17 00:00:00 2001

From: Christian 'Ansuel' Marangi <ansuelsmth@gmail.com>

Date: Thu, 22 Sep 2022 10:35:14 +0300

Subject: [PATCH] wifi: ath11k: fix peer addition/deletion error on sta band migration

Git-commit: d673cb6fe6c03b2be157cc6c5db40481828d282d

Patch-mainline: v6.1-rc1

References: bsc#1206451

This patch try to fix the following error.

Wed Jun  1 22:19:30 2022 kern.warn kernel: [  119.561227] ath11k c000000.wifi: peer already added vdev id 0 req, vdev id 1 present

Wed Jun  1 22:19:30 2022 kern.warn kernel: [  119.561282] ath11k c000000.wifi: Failed to add peer: 28:c2:1f:xx:xx:xx for VDEV: 0

Wed Jun  1 22:19:30 2022 kern.warn kernel: [  119.568053] ath11k c000000.wifi: Failed to add station: 28:c2:1f:xx:xx:xx for VDEV: 0

Wed Jun  1 22:19:31 2022 daemon.notice hostapd: wlan2: STA 28:c2:1f:xx:xx:xx IEEE 802.11: Could not add STA to kernel driver

Wed Jun  1 22:19:31 2022 daemon.notice hostapd: wlan2: STA 28:c2:1f:xx:xx:xx IEEE 802.11: did not acknowledge authentication response

Wed Jun  1 22:19:31 2022 daemon.notice hostapd: wlan1: AP-STA-DISCONNECTED 28:c2:1f:xx:xx:xx

Wed Jun  1 22:19:31 2022 daemon.info hostapd: wlan1: STA 28:c2:1f:xx:xx:xx IEEE 802.11: disassociated due to inactivity

Wed Jun  1 22:19:32 2022 daemon.info hostapd: wlan1: STA 28:c2:1f:xx:xx:xx IEEE 802.11: deauthenticated due to inactivity (timer DEAUTH/REMOVE)

To repro this:

- Have 2 Wifi with the same bssid and pass on different band (2.4 and

5GHz)

- Enable 802.11r Fast Transaction with same mobility domain

- FT Protocol: FT over the Air

From a openwrt system issue the command (with the correct mac)

ubus call hostapd.wlan1 wnm_disassoc_imminent '{"addr":"28:C2:1F:xx:xx:xx"}'

Notice the log printing the errors.

The cause of this error has been investigated and we found that this is

related to the WiFi Fast Transaction feature. We observed that this is

triggered when the router tells the device to change band. In this case

the device first auth to the other band and then the disconnect path

from the prev band is triggered.

This is problematic with the current rhash implementation since the

addrs is used as key and the logic of "adding first, delete later"

conflicts with the rhash logic.

In fact peer addition will fail since the peer is already added and with

that fixed a peer deletion will cause unitended effect by removing the

peer just added.

Current solution to this is to add additional logic to the peer delete,

make sure we are deleting the correct peer taken from the rhash

table (and fallback to the peer list) and for the peer add logic delete

the peer entry for the rhash list before adding the new one (counting as

an error only when a peer with the same vlan_id is asked to be added).

With this change, a sta can correctly transition from 2.4GHz and 5GHZ

with no drop and no error are printed.

Tested-on: IPQ8074 hw2.0 AHB WLAN.HK.2.5.0.1-01208-QCAHKSWPL_SILICONZ-1

Fixes: 7b0c70d92a43 ("ath11k: Add peer rhash table support")

Signed-off-by: Christian 'Ansuel' Marangi <ansuelsmth@gmail.com>

Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>

Link: https://lore.kernel.org/r/20220603164559.27769-1-ansuelsmth@gmail.com

Acked-by: Takashi Iwai <tiwai@suse.de>

---

 drivers/net/wireless/ath/ath11k/peer.c | 30 ++++++++++++++++++++++----

 1 file changed, 26 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/ath/ath11k/peer.c b/drivers/net/wireless/ath/ath11k/peer.c

index 9e22aaf34b88..1ae7af02c364 100644

--- a/drivers/net/wireless/ath/ath11k/peer.c

+++ b/drivers/net/wireless/ath/ath11k/peer.c

@@ -302,6 +302,21 @@ static int __ath11k_peer_delete(struct ath11k *ar, u32 vdev_id, const u8 *addr)

 	spin_lock_bh(&ab->base_lock);

 	peer = ath11k_peer_find_by_addr(ab, addr);

+	/* Check if the found peer is what we want to remove.

+	 * While the sta is transitioning to another band we may

+	 * have 2 peer with the same addr assigned to different

+	 * vdev_id. Make sure we are deleting the correct peer.

+	 */

+	if (peer && peer->vdev_id == vdev_id)

+		ath11k_peer_rhash_delete(ab, peer);

+

+	/* Fallback to peer list search if the correct peer can't be found.

+	 * Skip the deletion of the peer from the rhash since it has already

+	 * been deleted in peer add.

+	 */

+	if (!peer)

+		peer = ath11k_peer_find(ab, vdev_id, addr);

+

 	if (!peer) {

 		spin_unlock_bh(&ab->base_lock);

 		mutex_unlock(&ab->tbl_mtx_lock);

@@ -312,8 +327,6 @@ static int __ath11k_peer_delete(struct ath11k *ar, u32 vdev_id, const u8 *addr)

 		return -EINVAL;

 	}

-	ath11k_peer_rhash_delete(ab, peer);

-

 	spin_unlock_bh(&ab->base_lock);

 	mutex_unlock(&ab->tbl_mtx_lock);

@@ -372,8 +385,17 @@ int ath11k_peer_create(struct ath11k *ar, struct ath11k_vif *arvif,

 	spin_lock_bh(&ar->ab->base_lock);

 	peer = ath11k_peer_find_by_addr(ar->ab, param->peer_addr);

 	if (peer) {

-		spin_unlock_bh(&ar->ab->base_lock);

-		return -EINVAL;

+		if (peer->vdev_id == param->vdev_id) {

+			spin_unlock_bh(&ar->ab->base_lock);

+			return -EINVAL;

+		}

+

+		/* Assume sta is transitioning to another band.

+		 * Remove here the peer from rhash.

+		 */

+		mutex_lock(&ar->ab->tbl_mtx_lock);

+		ath11k_peer_rhash_delete(ar->ab, peer);

+		mutex_unlock(&ar->ab->tbl_mtx_lock);

 	}

 	spin_unlock_bh(&ar->ab->base_lock);

-- 

2.35.3