wil6210: handle multiple connect/disconnect events

In the current solution wil6210 configures the vring in a worker
and holds only one pending CID. This implementation may lead to
race conditions between connect and disconnect events of multiple
stations or fast connect/disconnect events of the same station.

In order to allow the removal of the connect worker and handling of
WMI_VRING_CFG_DONE_EVENTID in the connect event, the WMI replies
that provide the reply in a given buffer needs to be handled
immediately in the WMI event interrupt thread.
To prevent deadlocks, WMI replies that requires additional
handling are still handled via the events list.

Signed-off-by: Maya Erez <qca_merez@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

1 files changed, 36 insertions, 45 deletions

diff --git a/drivers/net/wireless/ath/wil6210/main.c b/drivers/net/wireless/ath/wil6210/main.c
index b39f0bf..0652efe 100644
--- a/drivers/net/wireless/ath/wil6210/main.c
+++ b/drivers/net/wireless/ath/wil6210/main.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012-2015 Qualcomm Atheros, Inc.
+ * Copyright (c) 2012-2016 Qualcomm Atheros, Inc.
  *
  * Permission to use, copy, modify, and/or distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -155,7 +155,7 @@ __acquires(&sta->tid_rx_lock) __releases(&sta->tid_rx_lock)
 
 	if (sta->status != wil_sta_unused) {
 		if (!from_event)
-			wmi_disconnect_sta(wil, sta->addr, reason_code);
+			wmi_disconnect_sta(wil, sta->addr, reason_code, true);
 
 		switch (wdev->iftype) {
 		case NL80211_IFTYPE_AP:
@@ -195,8 +195,8 @@ static void _wil6210_disconnect(struct wil6210_priv *wil, const u8 *bssid,
 	struct wireless_dev *wdev = wil->wdev;
 
 	might_sleep();
-	wil_dbg_misc(wil, "%s(bssid=%pM, reason=%d, ev%s)\n", __func__, bssid,
-		     reason_code, from_event ? "+" : "-");
+	wil_info(wil, "%s(bssid=%pM, reason=%d, ev%s)\n", __func__, bssid,
+		 reason_code, from_event ? "+" : "-");
 
 	/* Cases are:
 	 * - disconnect single STA, still connected
@@ -258,13 +258,16 @@ static void wil_disconnect_worker(struct work_struct *work)
 static void wil_connect_timer_fn(ulong x)
 {
 	struct wil6210_priv *wil = (void *)x;
+	bool q;
 
-	wil_dbg_misc(wil, "Connect timeout\n");
+	wil_err(wil, "Connect timeout detected, disconnect station\n");
 
 	/* reschedule to thread context - disconnect won't
-	 * run from atomic context
+	 * run from atomic context.
+	 * queue on wmi_wq to prevent race with connect event.
 	 */
-	schedule_work(&wil->disconnect_worker);
+	q = queue_work(wil->wmi_wq, &wil->disconnect_worker);
+	wil_dbg_wmi(wil, "queue_work of disconnect_worker -> %d\n", q);
 }
 
 static void wil_scan_timer_fn(ulong x)
@@ -369,6 +372,32 @@ static int wil_find_free_vring(struct wil6210_priv *wil)
 	return -EINVAL;
 }
 
+int wil_tx_init(struct wil6210_priv *wil, int cid)
+{
+	int rc = -EINVAL, ringid;
+
+	if (cid < 0) {
+		wil_err(wil, "No connection pending\n");
+		goto out;
+	}
+	ringid = wil_find_free_vring(wil);
+	if (ringid < 0) {
+		wil_err(wil, "No free vring found\n");
+		goto out;
+	}
+
+	wil_dbg_wmi(wil, "Configure for connection CID %d vring %d\n",
+		    cid, ringid);
+
+	rc = wil_vring_init_tx(wil, ringid, 1 << tx_ring_order, cid, 0);
+	if (rc)
+		wil_err(wil, "wil_vring_init_tx for CID %d vring %d failed\n",
+			cid, ringid);
+
+out:
+	return rc;
+}
+
 int wil_bcast_init(struct wil6210_priv *wil)
 {
 	int ri = wil->bcast_vring, rc;
@@ -399,41 +428,6 @@ void wil_bcast_fini(struct wil6210_priv *wil)
 	wil_vring_fini_tx(wil, ri);
 }
 
-static void wil_connect_worker(struct work_struct *work)
-{
-	int rc, cid, ringid;
-	struct wil6210_priv *wil = container_of(work, struct wil6210_priv,
-						connect_worker);
-	struct net_device *ndev = wil_to_ndev(wil);
-
-	mutex_lock(&wil->mutex);
-
-	cid = wil->pending_connect_cid;
-	if (cid < 0) {
-		wil_err(wil, "No connection pending\n");
-		goto out;
-	}
-	ringid = wil_find_free_vring(wil);
-	if (ringid < 0) {
-		wil_err(wil, "No free vring found\n");
-		goto out;
-	}
-
-	wil_dbg_wmi(wil, "Configure for connection CID %d vring %d\n",
-		    cid, ringid);
-
-	rc = wil_vring_init_tx(wil, ringid, 1 << tx_ring_order, cid, 0);
-	wil->pending_connect_cid = -1;
-	if (rc == 0) {
-		wil->sta[cid].status = wil_sta_connected;
-		netif_tx_wake_all_queues(ndev);
-	} else {
-		wil_disconnect_cid(wil, cid, WLAN_REASON_UNSPECIFIED, true);
-	}
-out:
-	mutex_unlock(&wil->mutex);
-}
-
 int wil_priv_init(struct wil6210_priv *wil)
 {
 	uint i;
@@ -453,12 +447,10 @@ int wil_priv_init(struct wil6210_priv *wil)
 	init_completion(&wil->wmi_ready);
 	init_completion(&wil->wmi_call);
 
-	wil->pending_connect_cid = -1;
 	wil->bcast_vring = -1;
 	setup_timer(&wil->connect_timer, wil_connect_timer_fn, (ulong)wil);
 	setup_timer(&wil->scan_timer, wil_scan_timer_fn, (ulong)wil);
 
-	INIT_WORK(&wil->connect_worker, wil_connect_worker);
 	INIT_WORK(&wil->disconnect_worker, wil_disconnect_worker);
 	INIT_WORK(&wil->wmi_event_worker, wmi_event_worker);
 	INIT_WORK(&wil->fw_error_worker, wil_fw_error_worker);
@@ -844,7 +836,6 @@ int wil_reset(struct wil6210_priv *wil, bool load_fw)
 	}
 
 	/* init after reset */
-	wil->pending_connect_cid = -1;
 	wil->ap_isolate = 0;
 	reinit_completion(&wil->wmi_ready);
 	reinit_completion(&wil->wmi_call);