mt76: convert from tx tasklet to tx worker thread

This improves performance by allowing the scheduler to move the tx scheduling
work to idle CPUs. Since tx scheduling work is very latency sensitive and
kept short via AQL, sched_set_fifo_low is used to keep worker priority above
normal tasks

Signed-off-by: Felix Fietkau <nbd@nbd.name>

1 files changed, 8 insertions, 6 deletions

diff --git a/drivers/net/wireless/mediatek/mt76/usb.c b/drivers/net/wireless/mediatek/mt76/usb.c
index 18dbecafb7a0..edbcabd2b797 100644
--- a/drivers/net/wireless/mediatek/mt76/usb.c
+++ b/drivers/net/wireless/mediatek/mt76/usb.c
@@ -792,9 +792,9 @@ int mt76u_resume_rx(struct mt76_dev *dev)
 }
 EXPORT_SYMBOL_GPL(mt76u_resume_rx);
 
-static void mt76u_tx_tasklet(unsigned long data)
+static void mt76u_tx_worker(struct mt76_worker *w)
 {
-	struct mt76_dev *dev = (struct mt76_dev *)data;
+	struct mt76_dev *dev = container_of(w, struct mt76_dev, tx_worker);
 	struct mt76_queue_entry entry;
 	struct mt76_queue *q;
 	bool wake;
@@ -864,7 +864,7 @@ static void mt76u_complete_tx(struct urb *urb)
 		dev_err(dev->dev, "tx urb failed: %d\n", urb->status);
 	e->done = true;
 
-	tasklet_schedule(&dev->tx_tasklet);
+	mt76_worker_schedule(&dev->tx_worker);
 }
 
 static int
@@ -1020,6 +1020,8 @@ void mt76u_stop_tx(struct mt76_dev *dev)
 {
 	int ret;
 
+	mt76_worker_disable(&dev->tx_worker);
+
 	ret = wait_event_timeout(dev->tx_wait, !mt76_has_tx_pending(&dev->phy),
 				 HZ / 5);
 	if (!ret) {
@@ -1038,8 +1040,6 @@ void mt76u_stop_tx(struct mt76_dev *dev)
 				usb_kill_urb(q->entry[j].urb);
 		}
 
-		tasklet_kill(&dev->tx_tasklet);
-
 		/* On device removal we maight queue skb's, but mt76u_tx_kick()
 		 * will fail to submit urb, cleanup those skb's manually.
 		 */
@@ -1058,6 +1058,8 @@ void mt76u_stop_tx(struct mt76_dev *dev)
 	cancel_work_sync(&dev->usb.stat_work);
 	clear_bit(MT76_READING_STATS, &dev->phy.state);
 
+	mt76_worker_enable(&dev->tx_worker);
+
 	mt76_tx_status_check(dev, NULL, true);
 }
 EXPORT_SYMBOL_GPL(mt76u_stop_tx);
@@ -1107,8 +1109,8 @@ int mt76u_init(struct mt76_dev *dev,
 	mt76u_ops.rmw = ext ? mt76u_rmw_ext : mt76u_rmw;
 	mt76u_ops.write_copy = ext ? mt76u_copy_ext : mt76u_copy;
 
+	dev->tx_worker.fn = mt76u_tx_worker;
 	tasklet_init(&usb->rx_tasklet, mt76u_rx_tasklet, (unsigned long)dev);
-	tasklet_init(&dev->tx_tasklet, mt76u_tx_tasklet, (unsigned long)dev);
 	INIT_WORK(&usb->stat_work, mt76u_tx_status_data);
 
 	usb->data_len = usb_maxpacket(udev, usb_sndctrlpipe(udev, 0), 1);