Commit f7522949 authored by Lorenzo Bianconi's avatar Lorenzo Bianconi Committed by Felix Fietkau
Browse files

mt76: usb: use a linear buffer for tx/rx datapath if sg is not supported 



Use linear fragment and not a single usb scatter-gather buffer in mt76u
{tx,rx} datapath if the usb controller has sg data length constraints

Signed-off-by: default avatarLorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: default avatarFelix Fietkau <nbd@nbd.name>
parent d704d16f

drivers/net/wireless/mediatek/mt76/usb.c

+54 −33
Original line number Diff line number Diff line
@@ -432,10 +432,11 @@ static int mt76u_get_rx_entry_len(u8 *data, u32 data_len) 
}



static int

mt76u_process_rx_entry(struct mt76_dev *dev, struct urb *urb)

mt76u_process_rx_entry(struct mt76_dev *dev, struct mt76u_buf *buf)

{

	struct mt76_queue *q = &dev->q_rx[MT_RXQ_MAIN];

	u8 *data = sg_virt(&urb->sg[0]);

	struct urb *urb = buf->urb;

	u8 *data = urb->num_sgs ? sg_virt(&urb->sg[0]) : buf->buf;

	int data_len, len, nsgs = 1;

	struct sk_buff *skb;
@@ -446,7 +447,8 @@ mt76u_process_rx_entry(struct mt76_dev *dev, struct urb *urb) 
	if (len < 0)

		return 0;



	data_len = min_t(int, len, urb->sg[0].length - MT_DMA_HDR_LEN);

	data_len = urb->num_sgs ? urb->sg[0].length : buf->len;

	data_len = min_t(int, len, data_len - MT_DMA_HDR_LEN);

	if (MT_DMA_HDR_LEN + data_len > SKB_WITH_OVERHEAD(q->buf_size))

		return 0;
@@ -458,7 +460,7 @@ mt76u_process_rx_entry(struct mt76_dev *dev, struct urb *urb) 
	__skb_put(skb, data_len);

	len -= data_len;



	while (len > 0) {

	while (len > 0 && urb->num_sgs) {

		data_len = min_t(int, len, urb->sg[nsgs].length);

		skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags,

				sg_page(&urb->sg[nsgs]),
@@ -503,12 +505,26 @@ static void mt76u_complete_rx(struct urb *urb) 
	spin_unlock_irqrestore(&q->lock, flags);

}



static int

mt76u_refill_rx(struct mt76_dev *dev, struct mt76_queue *q,

		struct mt76u_buf *buf, int nsgs)

{

	if (dev->usb.sg_en) {

		return mt76u_fill_rx_sg(dev, buf, nsgs, q->buf_size,

					SKB_WITH_OVERHEAD(q->buf_size));

	} else {

		buf->buf = page_frag_alloc(&q->rx_page, q->buf_size,

					   GFP_ATOMIC);

		return buf->buf ? 0 : -ENOMEM;

	}

}



static void mt76u_rx_tasklet(unsigned long data)

{

	struct mt76_dev *dev = (struct mt76_dev *)data;

	struct mt76_queue *q = &dev->q_rx[MT_RXQ_MAIN];

	int err, nsgs, buf_len = q->buf_size;

	struct mt76u_buf *buf;

	int err, count;



	rcu_read_lock();
@@ -517,11 +533,9 @@ static void mt76u_rx_tasklet(unsigned long data) 
		if (!buf)

			break;



		nsgs = mt76u_process_rx_entry(dev, buf->urb);

		if (nsgs > 0) {

			err = mt76u_fill_rx_sg(dev, buf, nsgs,

					       buf_len,

					       SKB_WITH_OVERHEAD(buf_len));

		count = mt76u_process_rx_entry(dev, buf);

		if (count > 0) {

			err = mt76u_refill_rx(dev, q, buf, count);

			if (err < 0)

				break;

		}
@@ -559,7 +573,7 @@ EXPORT_SYMBOL_GPL(mt76u_submit_rx_buffers); 
static int mt76u_alloc_rx(struct mt76_dev *dev)

{

	struct mt76_queue *q = &dev->q_rx[MT_RXQ_MAIN];

	int i, err, nsgs;

	int i, err;



	spin_lock_init(&q->rx_page_lock);

	spin_lock_init(&q->lock);
@@ -569,18 +583,17 @@ static int mt76u_alloc_rx(struct mt76_dev *dev) 
	if (!q->entry)

		return -ENOMEM;



	if (dev->usb.sg_en) {

		q->buf_size = MT_RX_BUF_SIZE;

		nsgs = MT_SG_MAX_SIZE;

	} else {

		q->buf_size = PAGE_SIZE;

		nsgs = 1;

	}



	q->buf_size = dev->usb.sg_en ? MT_RX_BUF_SIZE : PAGE_SIZE;

	q->ndesc = MT_NUM_RX_ENTRIES;

	for (i = 0; i < q->ndesc; i++) {

		if (dev->usb.sg_en)

			err = mt76u_buf_alloc_sg(dev, &q->entry[i].ubuf,

					 nsgs, q->buf_size,

					MT_SG_MAX_SIZE, q->buf_size,

					SKB_WITH_OVERHEAD(q->buf_size),

					GFP_KERNEL);

		else

			err = mt76u_buf_alloc(dev, &q->entry[i].ubuf,

					      q->buf_size,

					      SKB_WITH_OVERHEAD(q->buf_size),

					      GFP_KERNEL);

		if (err < 0)
@@ -730,7 +743,7 @@ mt76u_tx_queue_skb(struct mt76_dev *dev, struct mt76_queue *q, 
{

	struct usb_interface *intf = to_usb_interface(dev->dev);

	struct usb_device *udev = interface_to_usbdev(intf);

	u8 ep = q2ep(q->hw_idx);

	u8 *data = NULL, ep = q2ep(q->hw_idx);

	struct mt76u_buf *buf;

	u16 idx = q->tail;

	unsigned int pipe;
@@ -747,12 +760,16 @@ mt76u_tx_queue_skb(struct mt76_dev *dev, struct mt76_queue *q, 
	buf = &q->entry[idx].ubuf;

	buf->done = false;



	if (dev->usb.sg_en) {

		err = mt76u_tx_build_sg(skb, buf->urb);

		if (err < 0)

			return err;

	} else {

		data = skb->data;

	}



	pipe = usb_sndbulkpipe(udev, dev->usb.out_ep[ep]);

	usb_fill_bulk_urb(buf->urb, udev, pipe, NULL, skb->len,

	usb_fill_bulk_urb(buf->urb, udev, pipe, data, skb->len,

			  mt76u_complete_tx, buf);



	q->tail = (q->tail + 1) % q->ndesc;
@@ -788,10 +805,8 @@ static int mt76u_alloc_tx(struct mt76_dev *dev) 
{

	struct mt76u_buf *buf;

	struct mt76_queue *q;

	size_t size;

	int i, j;



	size = MT_SG_MAX_SIZE * sizeof(struct scatterlist);

	for (i = 0; i < IEEE80211_NUM_ACS; i++) {

		q = &dev->q_tx[i];

		spin_lock_init(&q->lock);
@@ -813,11 +828,17 @@ static int mt76u_alloc_tx(struct mt76_dev *dev) 
			if (!buf->urb)

				return -ENOMEM;



			buf->urb->sg = devm_kzalloc(dev->dev, size, GFP_KERNEL);

			if (dev->usb.sg_en) {

				size_t size = MT_SG_MAX_SIZE *

					      sizeof(struct scatterlist);



				buf->urb->sg = devm_kzalloc(dev->dev, size,

							    GFP_KERNEL);

				if (!buf->urb->sg)

					return -ENOMEM;

			}

		}

	}

	return 0;

}