wil6210: remove BACK RX and TX workers

WMI synchronous handling has changed and WMI calls that provide
a buffer for the reply are completed in the WMI interrupt context.
This allows sending the RX and TX BACK commands from the WMI event
handler without the need for the worker thread.
This is a better approach as it can decrease the handshake time
in the connect flow and prevent race conditions in case of fast
disconnects. An example for such a race is handling of wil_back_rx_handle
during a disconnect event, as wil_back_rx_handle is not protected by
the wil mutex and a disconnect can be handled after sta->status is
verified as connected.

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

3 files changed, 41 insertions, 202 deletions

diff --git a/drivers/net/wireless/ath/wil6210/main.c b/drivers/net/wireless/ath/wil6210/main.c
index 78ba6e04c944..35db9940c519 100644
--- a/drivers/net/wireless/ath/wil6210/main.c
+++ b/drivers/net/wireless/ath/wil6210/main.c
@@ -440,8 +440,6 @@ int wil_priv_init(struct wil6210_priv *wil)
 
 	mutex_init(&wil->mutex);
 	mutex_init(&wil->wmi_mutex);
-	mutex_init(&wil->back_rx_mutex);
-	mutex_init(&wil->back_tx_mutex);
 	mutex_init(&wil->probe_client_mutex);
 
 	init_completion(&wil->wmi_ready);
@@ -454,13 +452,9 @@ int wil_priv_init(struct wil6210_priv *wil)
 	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);
-	INIT_WORK(&wil->back_rx_worker, wil_back_rx_worker);
-	INIT_WORK(&wil->back_tx_worker, wil_back_tx_worker);
 	INIT_WORK(&wil->probe_client_worker, wil_probe_client_worker);
 
 	INIT_LIST_HEAD(&wil->pending_wmi_ev);
-	INIT_LIST_HEAD(&wil->back_rx_pending);
-	INIT_LIST_HEAD(&wil->back_tx_pending);
 	INIT_LIST_HEAD(&wil->probe_client_pending);
 	spin_lock_init(&wil->wmi_ev_lock);
 	init_waitqueue_head(&wil->wq);
@@ -520,10 +514,6 @@ void wil_priv_deinit(struct wil6210_priv *wil)
 	wil6210_disconnect(wil, NULL, WLAN_REASON_DEAUTH_LEAVING, false);
 	mutex_unlock(&wil->mutex);
 	wmi_event_flush(wil);
-	wil_back_rx_flush(wil);
-	cancel_work_sync(&wil->back_rx_worker);
-	wil_back_tx_flush(wil);
-	cancel_work_sync(&wil->back_tx_worker);
 	wil_probe_client_flush(wil);
 	cancel_work_sync(&wil->probe_client_worker);
 	destroy_workqueue(wil->wq_service);
diff --git a/drivers/net/wireless/ath/wil6210/rx_reorder.c b/drivers/net/wireless/ath/wil6210/rx_reorder.c
index 32031e7a11d5..19ed127d4d05 100644
--- a/drivers/net/wireless/ath/wil6210/rx_reorder.c
+++ b/drivers/net/wireless/ath/wil6210/rx_reorder.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014-2015 Qualcomm Atheros, Inc.
+ * Copyright (c) 2014-2016 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
@@ -291,35 +291,15 @@ static u16 wil_agg_size(struct wil6210_priv *wil, u16 req_agg_wsize)
 	return min(max_agg_size, req_agg_wsize);
 }
 
-/* Block Ack - Rx side (recipient */
+/* Block Ack - Rx side (recipient) */
 int wil_addba_rx_request(struct wil6210_priv *wil, u8 cidxtid,
 			 u8 dialog_token, __le16 ba_param_set,
 			 __le16 ba_timeout, __le16 ba_seq_ctrl)
-{
-	struct wil_back_rx *req = kzalloc(sizeof(*req), GFP_KERNEL);
-
-	if (!req)
-		return -ENOMEM;
-
-	req->cidxtid = cidxtid;
-	req->dialog_token = dialog_token;
-	req->ba_param_set = le16_to_cpu(ba_param_set);
-	req->ba_timeout = le16_to_cpu(ba_timeout);
-	req->ba_seq_ctrl = le16_to_cpu(ba_seq_ctrl);
-
-	mutex_lock(&wil->back_rx_mutex);
-	list_add_tail(&req->list, &wil->back_rx_pending);
-	mutex_unlock(&wil->back_rx_mutex);
-
-	queue_work(wil->wq_service, &wil->back_rx_worker);
-
-	return 0;
-}
-
-static void wil_back_rx_handle(struct wil6210_priv *wil,
-			       struct wil_back_rx *req)
 __acquires(&sta->tid_rx_lock) __releases(&sta->tid_rx_lock)
 {
+	u16 param_set = le16_to_cpu(ba_param_set);
+	u16 agg_timeout = le16_to_cpu(ba_timeout);
+	u16 seq_ctrl = le16_to_cpu(ba_seq_ctrl);
 	struct wil_sta_info *sta;
 	u8 cid, tid;
 	u16 agg_wsize = 0;
@@ -328,34 +308,35 @@ __acquires(&sta->tid_rx_lock) __releases(&sta->tid_rx_lock)
 	 * bits 2..5: TID
 	 * bits 6..15: buffer size
 	 */
-	u16 req_agg_wsize = WIL_GET_BITS(req->ba_param_set, 6, 15);
-	bool agg_amsdu = !!(req->ba_param_set & BIT(0));
-	int ba_policy = req->ba_param_set & BIT(1);
-	u16 agg_timeout = req->ba_timeout;
+	u16 req_agg_wsize = WIL_GET_BITS(param_set, 6, 15);
+	bool agg_amsdu = !!(param_set & BIT(0));
+	int ba_policy = param_set & BIT(1);
 	u16 status = WLAN_STATUS_SUCCESS;
-	u16 ssn = req->ba_seq_ctrl >> 4;
+	u16 ssn = seq_ctrl >> 4;
 	struct wil_tid_ampdu_rx *r;
-	int rc;
+	int rc = 0;
 
 	might_sleep();
-	parse_cidxtid(req->cidxtid, &cid, &tid);
+	parse_cidxtid(cidxtid, &cid, &tid);
 
 	/* sanity checks */
 	if (cid >= WIL6210_MAX_CID) {
 		wil_err(wil, "BACK: invalid CID %d\n", cid);
-		return;
+		rc = -EINVAL;
+		goto out;
 	}
 
 	sta = &wil->sta[cid];
 	if (sta->status != wil_sta_connected) {
 		wil_err(wil, "BACK: CID %d not connected\n", cid);
-		return;
+		rc = -EINVAL;
+		goto out;
 	}
 
 	wil_dbg_wmi(wil,
 		    "ADDBA request for CID %d %pM TID %d size %d timeout %d AMSDU%s policy %d token %d SSN 0x%03x\n",
-		    cid, sta->addr, tid, req_agg_wsize, req->ba_timeout,
-		    agg_amsdu ? "+" : "-", !!ba_policy, req->dialog_token, ssn);
+		    cid, sta->addr, tid, req_agg_wsize, agg_timeout,
+		    agg_amsdu ? "+" : "-", !!ba_policy, dialog_token, ssn);
 
 	/* apply policies */
 	if (ba_policy) {
@@ -365,10 +346,13 @@ __acquires(&sta->tid_rx_lock) __releases(&sta->tid_rx_lock)
 	if (status == WLAN_STATUS_SUCCESS)
 		agg_wsize = wil_agg_size(wil, req_agg_wsize);
 
-	rc = wmi_addba_rx_resp(wil, cid, tid, req->dialog_token, status,
+	rc = wmi_addba_rx_resp(wil, cid, tid, dialog_token, status,
 			       agg_amsdu, agg_wsize, agg_timeout);
-	if (rc || (status != WLAN_STATUS_SUCCESS))
-		return;
+	if (rc || (status != WLAN_STATUS_SUCCESS)) {
+		wil_err(wil, "%s: do not apply ba, rc(%d), status(%d)\n",
+			__func__, rc, status);
+		goto out;
+	}
 
 	/* apply */
 	r = wil_tid_ampdu_rx_alloc(wil, agg_wsize, ssn);
@@ -376,143 +360,37 @@ __acquires(&sta->tid_rx_lock) __releases(&sta->tid_rx_lock)
 	wil_tid_ampdu_rx_free(wil, sta->tid_rx[tid]);
 	sta->tid_rx[tid] = r;
 	spin_unlock_bh(&sta->tid_rx_lock);
-}
-
-void wil_back_rx_flush(struct wil6210_priv *wil)
-{
-	struct wil_back_rx *evt, *t;
 
-	wil_dbg_misc(wil, "%s()\n", __func__);
-
-	mutex_lock(&wil->back_rx_mutex);
-
-	list_for_each_entry_safe(evt, t, &wil->back_rx_pending, list) {
-		list_del(&evt->list);
-		kfree(evt);
-	}
-
-	mutex_unlock(&wil->back_rx_mutex);
-}
-
-/* Retrieve next ADDBA request from the pending list */
-static struct list_head *next_back_rx(struct wil6210_priv *wil)
-{
-	struct list_head *ret = NULL;
-
-	mutex_lock(&wil->back_rx_mutex);
-
-	if (!list_empty(&wil->back_rx_pending)) {
-		ret = wil->back_rx_pending.next;
-		list_del(ret);
-	}
-
-	mutex_unlock(&wil->back_rx_mutex);
-
-	return ret;
-}
-
-void wil_back_rx_worker(struct work_struct *work)
-{
-	struct wil6210_priv *wil = container_of(work, struct wil6210_priv,
-						back_rx_worker);
-	struct wil_back_rx *evt;
-	struct list_head *lh;
-
-	while ((lh = next_back_rx(wil)) != NULL) {
-		evt = list_entry(lh, struct wil_back_rx, list);
-
-		wil_back_rx_handle(wil, evt);
-		kfree(evt);
-	}
+out:
+	return rc;
 }
 
-/* BACK - Tx (originator) side */
-static void wil_back_tx_handle(struct wil6210_priv *wil,
-			       struct wil_back_tx *req)
+/* BACK - Tx side (originator) */
+int wil_addba_tx_request(struct wil6210_priv *wil, u8 ringid, u16 wsize)
 {
-	struct vring_tx_data *txdata = &wil->vring_tx_data[req->ringid];
-	int rc;
+	u8 agg_wsize = wil_agg_size(wil, wsize);
+	u16 agg_timeout = 0;
+	struct vring_tx_data *txdata = &wil->vring_tx_data[ringid];
+	int rc = 0;
 
 	if (txdata->addba_in_progress) {
 		wil_dbg_misc(wil, "ADDBA for vring[%d] already in progress\n",
-			     req->ringid);
-		return;
+			     ringid);
+		goto out;
 	}
 	if (txdata->agg_wsize) {
 		wil_dbg_misc(wil,
-			     "ADDBA for vring[%d] already established wsize %d\n",
-			     req->ringid, txdata->agg_wsize);
-		return;
+			     "ADDBA for vring[%d] already done for wsize %d\n",
+			     ringid, txdata->agg_wsize);
+		goto out;
 	}
 	txdata->addba_in_progress = true;
-	rc = wmi_addba(wil, req->ringid, req->agg_wsize, req->agg_timeout);
-	if (rc)
+	rc = wmi_addba(wil, ringid, agg_wsize, agg_timeout);
+	if (rc) {
+		wil_err(wil, "%s: wmi_addba failed, rc (%d)", __func__, rc);
 		txdata->addba_in_progress = false;
-}
-
-static struct list_head *next_back_tx(struct wil6210_priv *wil)
-{
-	struct list_head *ret = NULL;
-
-	mutex_lock(&wil->back_tx_mutex);
-
-	if (!list_empty(&wil->back_tx_pending)) {
-		ret = wil->back_tx_pending.next;
-		list_del(ret);
-	}
-
-	mutex_unlock(&wil->back_tx_mutex);
-
-	return ret;
-}
-
-void wil_back_tx_worker(struct work_struct *work)
-{
-	struct wil6210_priv *wil = container_of(work, struct wil6210_priv,
-						 back_tx_worker);
-	struct wil_back_tx *evt;
-	struct list_head *lh;
-
-	while ((lh = next_back_tx(wil)) != NULL) {
-		evt = list_entry(lh, struct wil_back_tx, list);
-
-		wil_back_tx_handle(wil, evt);
-		kfree(evt);
 	}
-}
-
-void wil_back_tx_flush(struct wil6210_priv *wil)
-{
-	struct wil_back_tx *evt, *t;
-
-	wil_dbg_misc(wil, "%s()\n", __func__);
-
-	mutex_lock(&wil->back_tx_mutex);
-
-	list_for_each_entry_safe(evt, t, &wil->back_tx_pending, list) {
-		list_del(&evt->list);
-		kfree(evt);
-	}
-
-	mutex_unlock(&wil->back_tx_mutex);
-}
-
-int wil_addba_tx_request(struct wil6210_priv *wil, u8 ringid, u16 wsize)
-{
-	struct wil_back_tx *req = kzalloc(sizeof(*req), GFP_KERNEL);
-
-	if (!req)
-		return -ENOMEM;
 
-	req->ringid = ringid;
-	req->agg_wsize = wil_agg_size(wil, wsize);
-	req->agg_timeout = 0;
-
-	mutex_lock(&wil->back_tx_mutex);
-	list_add_tail(&req->list, &wil->back_tx_pending);
-	mutex_unlock(&wil->back_tx_mutex);
-
-	queue_work(wil->wq_service, &wil->back_tx_worker);
-
-	return 0;
+out:
+	return rc;
 }
diff --git a/drivers/net/wireless/ath/wil6210/wil6210.h b/drivers/net/wireless/ath/wil6210/wil6210.h
index 8427d68b6fa8..d59c3f29941e 100644
--- a/drivers/net/wireless/ath/wil6210/wil6210.h
+++ b/drivers/net/wireless/ath/wil6210/wil6210.h
@@ -507,24 +507,6 @@ enum {
 	hw_capability_last
 };
 
-struct wil_back_rx {
-	struct list_head list;
-	/* request params, converted to CPU byte order - what we asked for */
-	u8 cidxtid;
-	u8 dialog_token;
-	u16 ba_param_set;
-	u16 ba_timeout;
-	u16 ba_seq_ctrl;
-};
-
-struct wil_back_tx {
-	struct list_head list;
-	/* request params, converted to CPU byte order - what we asked for */
-	u8 ringid;
-	u8 agg_wsize;
-	u16 agg_timeout;
-};
-
 struct wil_probe_client_req {
 	struct list_head list;
 	u64 cookie;
@@ -595,13 +577,6 @@ struct wil6210_priv {
 	spinlock_t wmi_ev_lock;
 	struct napi_struct napi_rx;
 	struct napi_struct napi_tx;
-	/* BACK */
-	struct list_head back_rx_pending;
-	struct mutex back_rx_mutex; /* protect @back_rx_pending */
-	struct work_struct back_rx_worker;
-	struct list_head back_tx_pending;
-	struct mutex back_tx_mutex; /* protect @back_tx_pending */
-	struct work_struct back_tx_worker;
 	/* keep alive */
 	struct list_head probe_client_pending;
 	struct mutex probe_client_mutex; /* protect @probe_client_pending */
@@ -765,11 +740,7 @@ int wmi_addba_rx_resp(struct wil6210_priv *wil, u8 cid, u8 tid, u8 token,
 int wil_addba_rx_request(struct wil6210_priv *wil, u8 cidxtid,
 			 u8 dialog_token, __le16 ba_param_set,
 			 __le16 ba_timeout, __le16 ba_seq_ctrl);
-void wil_back_rx_worker(struct work_struct *work);
-void wil_back_rx_flush(struct wil6210_priv *wil);
 int wil_addba_tx_request(struct wil6210_priv *wil, u8 ringid, u16 wsize);
-void wil_back_tx_worker(struct work_struct *work);
-void wil_back_tx_flush(struct wil6210_priv *wil);
 
 void wil6210_clear_irq(struct wil6210_priv *wil);
 int wil6210_init_irq(struct wil6210_priv *wil, int irq, bool use_msi);