wifi: brcmfmac: fix continuous 802.1x tx pending timeout error

The race condition in brcmf_msgbuf_txflow and brcmf_msgbuf_delete_flowring
makes tx_msghdr writing after brcmf_msgbuf_remove_flowring. Host
driver should delete flowring after txflow complete and all txstatus back,
or pend_8021x_cnt will never be zero and cause every connection 950
milliseconds(MAX_WAIT_FOR_8021X_TX) delay.
Signed-off-by: Wright Feng <wright.feng@cypress.com>
Signed-off-by: Chi-hsien Lin <chi-hsien.lin@cypress.com>
Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Alvin Šipraga <alsi@bang-olufsen.dk>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20220722115632.620681-2-alvin@pqrs.dk

drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c

@@ -1480,8 +1480,10 @@ int brcmf_netdev_wait_pend8021x(struct brcmf_if *ifp)
 				 !brcmf_get_pend_8021x_cnt(ifp),
 				 MAX_WAIT_FOR_8021X_TX);
 
-	if (!err)
+	if (!err) {
 		bphy_err(drvr, "Timed out waiting for no pending 802.1x packets\n");
+		atomic_set(&ifp->pend_8021x_cnt, 0);
+	}
 
 	return !err;
 }

drivers/net/wireless/broadcom/brcm80211/brcmfmac/msgbuf.c

@@ -71,6 +71,7 @@
 #define BRCMF_MSGBUF_TRICKLE_TXWORKER_THRS	32
 #define BRCMF_MSGBUF_UPDATE_RX_PTR_THRS		48
 
+#define BRCMF_MAX_TXSTATUS_WAIT_RETRIES		10
 
 struct msgbuf_common_hdr {
 	u8				msgtype;
@@ -806,8 +807,12 @@ static int brcmf_msgbuf_tx_queue_data(struct brcmf_pub *drvr, int ifidx,
 	flowid = brcmf_flowring_lookup(flow, eh->h_dest, skb->priority, ifidx);
 	if (flowid == BRCMF_FLOWRING_INVALID_ID) {
 		flowid = brcmf_msgbuf_flowring_create(msgbuf, ifidx, skb);
-		if (flowid == BRCMF_FLOWRING_INVALID_ID)
+		if (flowid == BRCMF_FLOWRING_INVALID_ID) {
 			return -ENOMEM;
+		} else {
+			brcmf_flowring_enqueue(flow, flowid, skb);
+			return 0;
+		}
 	}
 	queue_count = brcmf_flowring_enqueue(flow, flowid, skb);
 	force = ((queue_count % BRCMF_MSGBUF_TRICKLE_TXWORKER_THRS) == 0);
@@ -1395,9 +1400,25 @@ void brcmf_msgbuf_delete_flowring(struct brcmf_pub *drvr, u16 flowid)
 	struct brcmf_msgbuf *msgbuf = (struct brcmf_msgbuf *)drvr->proto->pd;
 	struct msgbuf_tx_flowring_delete_req *delete;
 	struct brcmf_commonring *commonring;
+	struct brcmf_commonring *commonring_del;
+
 	void *ret_ptr;
 	u8 ifidx;
 	int err;
+	int retry = BRCMF_MAX_TXSTATUS_WAIT_RETRIES;
+
+	/* wait for commonring txflow finished */
+	commonring_del = msgbuf->flowrings[flowid];
+	brcmf_commonring_lock(commonring_del);
+	while (retry && atomic_read(&commonring_del->outstanding_tx)) {
+		usleep_range(5000, 10000);
+		retry--;
+	}
+	brcmf_commonring_unlock(commonring_del);
+	if (!retry && atomic_read(&commonring_del->outstanding_tx)) {
+		brcmf_err("timed out waiting for txstatus\n");
+		atomic_set(&commonring_del->outstanding_tx, 0);
+	}
 
 	/* no need to submit if firmware can not be reached */
 	if (drvr->bus_if->state != BRCMF_BUS_UP) {