staging: rtl8723au: Use workqueue to handle interrupt complete processing

Split the old work handler into a workqueue for processing
usb_read_interrupt_complete() events that require more than ust
clearing the event, and leave the old handler to just handle event
clearing.

This means we can get rid of the hacks with magic pointers to
determine what actions needs to be taken in the work handler, and
as an extra bonus obsoletes the bizarre cbuf code.
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8723au/core/rtw_cmd.c

@@ -188,33 +188,23 @@ int rtw_init_cmd_priv23a(struct cmd_priv *pcmdpriv)
 
 /* forward definition */
 
-static void c2h_wk_callback(struct work_struct *work);
+static void rtw_irq_work(struct work_struct *work);
 
 u32 rtw_init_evt_priv23a(struct evt_priv *pevtpriv)
 {
 	atomic_set(&pevtpriv->event_seq, 0);
 	pevtpriv->evt_done_cnt = 0;
 
-	INIT_WORK(&pevtpriv->c2h_wk, c2h_wk_callback);
-	pevtpriv->c2h_wk_alive = false;
-	pevtpriv->c2h_queue = rtw_cbuf_alloc23a(C2H_QUEUE_MAX_LEN + 1);
+	pevtpriv->wq = alloc_workqueue("rtl8723au_evt", 0, 1);
+
+	INIT_WORK(&pevtpriv->irq_wk, rtw_irq_work);
 
 	return _SUCCESS;
 }
 
 void rtw_free_evt_priv23a(struct evt_priv *pevtpriv)
 {
-	cancel_work_sync(&pevtpriv->c2h_wk);
-	while (pevtpriv->c2h_wk_alive)
-		msleep(10);
-
-	while (!rtw_cbuf_empty23a(pevtpriv->c2h_queue)) {
-		void *c2h;
-		if ((c2h = rtw_cbuf_pop23a(pevtpriv->c2h_queue)) != NULL &&
-		    c2h != (void *)pevtpriv) {
-			kfree(c2h);
-		}
-	}
+	cancel_work_sync(&pevtpriv->irq_wk);
 }
 
 static int rtw_cmd_filter(struct cmd_priv *pcmdpriv, struct cmd_obj *cmd_obj)
@@ -1348,54 +1338,47 @@ s32 c2h_evt_hdl(struct rtw_adapter *adapter, struct c2h_evt_hdr *c2h_evt,
 	return ret;
 }
 
-static void c2h_wk_callback(struct work_struct *work)
+static void rtw_irq_work(struct work_struct *work)
 {
 	struct evt_priv *evtpriv;
 	struct rtw_adapter *adapter;
-	struct c2h_evt_hdr *c2h_evt;
-	c2h_id_filter ccx_id_filter;
 
-	evtpriv = container_of(work, struct evt_priv, c2h_wk);
+	evtpriv = container_of(work, struct evt_priv, irq_wk);
 	adapter = container_of(evtpriv, struct rtw_adapter, evtpriv);
-	ccx_id_filter = rtw_hal_c2h_id_filter_ccx23a(adapter);
 
-	evtpriv->c2h_wk_alive = true;
-
-	while (!rtw_cbuf_empty23a(evtpriv->c2h_queue)) {
-		c2h_evt = (struct c2h_evt_hdr *)
-			rtw_cbuf_pop23a(evtpriv->c2h_queue);
-		if (c2h_evt) {
-			/* This C2H event is read, clear it */
-			c2h_evt_clear23a(adapter);
-		} else if ((c2h_evt = (struct c2h_evt_hdr *)
-			    kmalloc(16, GFP_KERNEL))) {
-			if (!c2h_evt)
-				continue;
-			/* This C2H event is not read, read & clear now */
-			if (c2h_evt_read23a(adapter, (u8*)c2h_evt) != _SUCCESS)
-				continue;
-		}
+	c2h_evt_clear23a(adapter);
+}
 
-		/* Special pointer to trigger c2h_evt_clear23a only */
-		if ((void *)c2h_evt == (void *)evtpriv)
-			continue;
+void rtw_evt_work(struct work_struct *work)
+{
+	struct evt_work *ework;
+	struct rtw_adapter *adapter;
+	c2h_id_filter ccx_id_filter;
 
-		if (!c2h_evt_exist(c2h_evt)) {
-			kfree(c2h_evt);
-			continue;
-		}
+	ework = container_of(work, struct evt_work, work);
+	adapter = ework->adapter;
 
-		if (ccx_id_filter(c2h_evt->id) == true) {
-			/* Handle CCX report here */
-			rtw_hal_c2h_handler23a(adapter, c2h_evt);
-			kfree(c2h_evt);
-		} else {
-			/* Enqueue into cmd_thread for others */
-			rtw_c2h_wk_cmd23a(adapter, (u8 *)c2h_evt);
-		}
+	ccx_id_filter = rtw_hal_c2h_id_filter_ccx23a(adapter);
+
+	c2h_evt_clear23a(adapter);
+
+	if (!c2h_evt_exist(&ework->u.c2h_evt)) {
+		kfree(ework);
+		return;
 	}
 
-	evtpriv->c2h_wk_alive = false;
+	if (ccx_id_filter(ework->u.c2h_evt.id) == true) {
+		/* Handle CCX report here */
+		rtw_hal_c2h_handler23a(adapter, &ework->u.c2h_evt);
+		kfree(ework);
+	} else {
+		/*
+		 * Enqueue into cmd_thread for others.
+		 * ework will be turned into a c2h_evt and freed once it
+		 * has been consumed.
+		 */
+		rtw_c2h_wk_cmd23a(adapter, (u8 *)&ework->u.c2h_evt);
+	}
 }
 
 u8 rtw_drvextra_cmd_hdl23a(struct rtw_adapter *padapter, const u8 *pbuf)

drivers/staging/rtl8723au/hal/usb_ops_linux.c

@@ -369,29 +369,36 @@ static void usb_read_interrupt_complete(struct urb *purb, struct pt_regs *regs)
 			if (c2h_id_filter_ccx_8723a(c2h_evt->id)) {
 				/* Handle CCX report here */
 				handle_txrpt_ccx_8723a(padapter, (void *)(c2h_evt->payload));
-				/* Replace with special pointer to
-				   trigger c2h_evt_clear23a */
-				if (rtw_cbuf_push23a(padapter->evtpriv.c2h_queue,
-						  (void *)&padapter->evtpriv) !=
-				    _SUCCESS)
-					DBG_8723A("%s rtw_cbuf_push23a fail\n",
-						  __func__);
-				schedule_work(&padapter->evtpriv.c2h_wk);
-			} else if ((c2h_evt = (struct c2h_evt_hdr *)
-				    kmalloc(16, GFP_ATOMIC))) {
-				memcpy(c2h_evt, purb->transfer_buffer, 16);
-				if (rtw_cbuf_push23a(padapter->evtpriv.c2h_queue,
-						  (void *)c2h_evt) != _SUCCESS)
-					DBG_8723A("%s rtw_cbuf_push23a fail\n",
-						  __func__);
-				schedule_work(&padapter->evtpriv.c2h_wk);
+				schedule_work(&padapter->evtpriv.irq_wk);
 			} else {
-				/* Error handling for malloc fail */
-				if (rtw_cbuf_push23a(padapter->evtpriv.c2h_queue,
-						  (void *)NULL) != _SUCCESS)
-					DBG_8723A("%s rtw_cbuf_push23a fail\n",
-						  __func__);
-				schedule_work(&padapter->evtpriv.c2h_wk);
+				struct evt_work *c2w;
+				int res;
+
+				c2w = (struct evt_work *)
+					kmalloc(sizeof(struct evt_work),
+						GFP_ATOMIC);
+
+				if (!c2w) {
+					printk(KERN_WARNING "%s: unable to "
+					       "allocate work buffer\n",
+					       __func__);
+					goto urb_submit;
+				}
+
+				c2w->adapter = padapter;
+				INIT_WORK(&c2w->work, rtw_evt_work);
+				memcpy(c2w->u.buf, purb->transfer_buffer, 16);
+
+				res = queue_work(padapter->evtpriv.wq,
+						 &c2w->work);
+
+				if (!res) {
+					printk(KERN_ERR "%s: Call to "
+					       "queue_work() failed\n",
+					       __func__);
+					kfree(c2w);
+					goto urb_submit;
+				}
 			}
 		}
 

drivers/staging/rtl8723au/include/rtw_cmd.h

@@ -53,9 +53,8 @@ struct cmd_priv {
 #define C2H_QUEUE_MAX_LEN 10
 
 struct	evt_priv {
-	struct work_struct c2h_wk;
-	bool c2h_wk_alive;
-	struct rtw_cbuf *c2h_queue;
+	struct workqueue_struct *wq;
+	struct work_struct irq_wk;
 
 	atomic_t event_seq;
 	u8	*evt_buf;	/* shall be non-paged, and 4 bytes aligned */
@@ -79,8 +78,24 @@ struct c2h_evt_hdr {
 	u8 payload[0];
 };
 
+/*
+ * Do not reorder - this allows for struct evt_work to be passed on to
+ * rtw_c2h_wk_cmd23a() as a 'struct c2h_evt_hdr *' without making an
+ * additional copy.
+ */
+struct evt_work {
+	union {
+		struct c2h_evt_hdr c2h_evt;
+		u8 buf[16];
+	} u;
+	struct work_struct work;
+	struct rtw_adapter *adapter;
+};
+
 #define c2h_evt_exist(c2h_evt) ((c2h_evt)->id || (c2h_evt)->plen)
 
+void rtw_evt_work(struct work_struct *work);
+
 int rtw_enqueue_cmd23a(struct cmd_priv *pcmdpriv, struct cmd_obj *obj);
 void rtw_free_cmd_obj23a(struct cmd_obj *pcmd);