rt2800mmio: use timer and work for handling tx statuses timeouts

Sometimes we can get into situation when there are pending statuses,
but we do not get INT_SOURCE_CSR_TX_FIFO_STATUS. Handle this situation
by arming timeout timer and read statuses (it will fix case when
we just do not have irq) and queue work to handle case we missed
statues from hardware FIFO.
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/ralink/rt2x00/rt2800mmio.c

@@ -426,6 +426,9 @@ void rt2800mmio_start_queue(struct data_queue *queue)
 }
 EXPORT_SYMBOL_GPL(rt2800mmio_start_queue);
 
+/* 200 ms */
+#define TXSTATUS_TIMEOUT 200000000
+
 void rt2800mmio_kick_queue(struct data_queue *queue)
 {
 	struct rt2x00_dev *rt2x00dev = queue->rt2x00dev;
@@ -440,6 +443,8 @@ void rt2800mmio_kick_queue(struct data_queue *queue)
 		entry = rt2x00queue_get_entry(queue, Q_INDEX);
 		rt2x00mmio_register_write(rt2x00dev, TX_CTX_IDX(queue->qid),
 					  entry->entry_idx);
+		hrtimer_start(&rt2x00dev->txstatus_timer,
+			      TXSTATUS_TIMEOUT, HRTIMER_MODE_REL);
 		break;
 	case QID_MGMT:
 		entry = rt2x00queue_get_entry(queue, Q_INDEX);
@@ -484,12 +489,8 @@ void rt2800mmio_flush_queue(struct data_queue *queue, bool drop)
 		 * For TX queues schedule completion tasklet to catch
 		 * tx status timeouts, othewise just wait.
 		 */
-		if (tx_queue) {
-			tasklet_disable(&rt2x00dev->txstatus_tasklet);
-			rt2800_txdone(rt2x00dev, UINT_MAX);
-			rt2800_txdone_nostatus(rt2x00dev);
-			tasklet_enable(&rt2x00dev->txstatus_tasklet);
-		}
+		if (tx_queue)
+			queue_work(rt2x00dev->workqueue, &rt2x00dev->txdone_work);
 
 		/*
 		 * Wait for a little while to give the driver
@@ -627,6 +628,10 @@ void rt2800mmio_clear_entry(struct queue_entry *entry)
 		word = rt2x00_desc_read(entry_priv->desc, 1);
 		rt2x00_set_field32(&word, TXD_W1_DMA_DONE, 1);
 		rt2x00_desc_write(entry_priv->desc, 1, word);
+
+		/* If last entry stop txstatus timer */
+		if (entry->queue->length == 1)
+			hrtimer_cancel(&rt2x00dev->txstatus_timer);
 	}
 }
 EXPORT_SYMBOL_GPL(rt2800mmio_clear_entry);
@@ -759,6 +764,70 @@ int rt2800mmio_enable_radio(struct rt2x00_dev *rt2x00dev)
 }
 EXPORT_SYMBOL_GPL(rt2800mmio_enable_radio);
 
+static void rt2800mmio_work_txdone(struct work_struct *work)
+{
+	struct rt2x00_dev *rt2x00dev =
+	    container_of(work, struct rt2x00_dev, txdone_work);
+
+	if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
+		return;
+
+	while (!kfifo_is_empty(&rt2x00dev->txstatus_fifo) ||
+	       rt2800_txstatus_timeout(rt2x00dev)) {
+
+		tasklet_disable(&rt2x00dev->txstatus_tasklet);
+		rt2800_txdone(rt2x00dev, UINT_MAX);
+		rt2800_txdone_nostatus(rt2x00dev);
+		tasklet_enable(&rt2x00dev->txstatus_tasklet);
+	}
+
+	if (rt2800_txstatus_pending(rt2x00dev))
+		hrtimer_start(&rt2x00dev->txstatus_timer,
+			      TXSTATUS_TIMEOUT, HRTIMER_MODE_REL);
+}
+
+static enum hrtimer_restart rt2800mmio_tx_sta_fifo_timeout(struct hrtimer *timer)
+{
+	struct rt2x00_dev *rt2x00dev =
+	    container_of(timer, struct rt2x00_dev, txstatus_timer);
+
+	if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
+		goto out;
+
+	if (!rt2800_txstatus_pending(rt2x00dev))
+		goto out;
+
+	rt2800mmio_fetch_txstatus(rt2x00dev);
+	if (!kfifo_is_empty(&rt2x00dev->txstatus_fifo))
+		tasklet_schedule(&rt2x00dev->txstatus_tasklet);
+	else
+		queue_work(rt2x00dev->workqueue, &rt2x00dev->txdone_work);
+out:
+	return HRTIMER_NORESTART;
+}
+
+int rt2800mmio_probe_hw(struct rt2x00_dev *rt2x00dev)
+{
+	int retval;
+
+	retval = rt2800_probe_hw(rt2x00dev);
+	if (retval)
+		return retval;
+
+	/*
+	 * Set txstatus timer function.
+	 */
+	rt2x00dev->txstatus_timer.function = rt2800mmio_tx_sta_fifo_timeout;
+
+	/*
+	 * Overwrite TX done handler
+	 */
+	INIT_WORK(&rt2x00dev->txdone_work, rt2800mmio_work_txdone);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(rt2800mmio_probe_hw);
+
 MODULE_AUTHOR(DRV_PROJECT);
 MODULE_VERSION(DRV_VERSION);
 MODULE_DESCRIPTION("rt2800 MMIO library");

drivers/net/wireless/ralink/rt2x00/rt2800mmio.h

@@ -153,6 +153,7 @@ void rt2800mmio_stop_queue(struct data_queue *queue);
 void rt2800mmio_queue_init(struct data_queue *queue);
 
 /* Initialization functions */
+int rt2800mmio_probe_hw(struct rt2x00_dev *rt2x00dev);
 bool rt2800mmio_get_entry_state(struct queue_entry *entry);
 void rt2800mmio_clear_entry(struct queue_entry *entry);
 int rt2800mmio_init_queues(struct rt2x00_dev *rt2x00dev);

drivers/net/wireless/ralink/rt2x00/rt2800pci.c

@@ -346,7 +346,7 @@ static const struct rt2x00lib_ops rt2800pci_rt2x00_ops = {
 	.tbtt_tasklet		= rt2800mmio_tbtt_tasklet,
 	.rxdone_tasklet		= rt2800mmio_rxdone_tasklet,
 	.autowake_tasklet	= rt2800mmio_autowake_tasklet,
-	.probe_hw		= rt2800_probe_hw,
+	.probe_hw		= rt2800mmio_probe_hw,
 	.get_firmware_name	= rt2800pci_get_firmware_name,
 	.check_firmware		= rt2800_check_firmware,
 	.load_firmware		= rt2800_load_firmware,

drivers/net/wireless/ralink/rt2x00/rt2800soc.c

@@ -185,7 +185,7 @@ static const struct rt2x00lib_ops rt2800soc_rt2x00_ops = {
 	.tbtt_tasklet		= rt2800mmio_tbtt_tasklet,
 	.rxdone_tasklet		= rt2800mmio_rxdone_tasklet,
 	.autowake_tasklet	= rt2800mmio_autowake_tasklet,
-	.probe_hw		= rt2800_probe_hw,
+	.probe_hw		= rt2800mmio_probe_hw,
 	.get_firmware_name	= rt2800soc_get_firmware_name,
 	.check_firmware		= rt2800soc_check_firmware,
 	.load_firmware		= rt2800soc_load_firmware,

drivers/net/wireless/ralink/rt2x00/rt2x00dev.c

@@ -1391,6 +1391,8 @@ int rt2x00lib_probe_dev(struct rt2x00_dev *rt2x00dev)
 	mutex_init(&rt2x00dev->conf_mutex);
 	INIT_LIST_HEAD(&rt2x00dev->bar_list);
 	spin_lock_init(&rt2x00dev->bar_list_lock);
+	hrtimer_init(&rt2x00dev->txstatus_timer, CLOCK_MONOTONIC,
+		     HRTIMER_MODE_REL);
 
 	set_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags);
 
@@ -1515,6 +1517,8 @@ void rt2x00lib_remove_dev(struct rt2x00_dev *rt2x00dev)
 	cancel_delayed_work_sync(&rt2x00dev->autowakeup_work);
 	cancel_work_sync(&rt2x00dev->sleep_work);
 
+	hrtimer_cancel(&rt2x00dev->txstatus_timer);
+
 	/*
 	 * Kill the tx status tasklet.
 	 */