Commit 2a92b08b authored by Lorenzo Bianconi's avatar Lorenzo Bianconi Committed by Kalle Valo
Browse files

mt76: usb: fix rx A-MSDU support 



Commit f8f527b1 ("mt76: usb: use EP max packet aligned buffer sizes
for rx") breaks A-MSDU support. When A-MSDU is enable the device can
receive frames up to q->buf_size but they will be discarded in
mt76u_process_rx_entry since there is no enough room for
skb_shared_info. Fix the issue reallocating the skb and copying in the
linear area the first 128B of the received frames and in the frag_list
the remaining part

Fixes: f8f527b1 ("mt76: usb: use EP max packet aligned buffer sizes for rx")
Signed-off-by: default avatarLorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: default avatarKalle Valo <kvalo@codeaurora.org>
parent 0766789b

drivers/net/wireless/mediatek/mt76/mt76.h

+1 −0
Original line number Diff line number Diff line
@@ -30,6 +30,7 @@ 
#define MT_TX_RING_SIZE     256

#define MT_MCU_RING_SIZE    32

#define MT_RX_BUF_SIZE      2048

#define MT_SKB_HEAD_LEN     128



struct mt76_dev;

struct mt76_wcid;

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

+37 −9
Original line number Diff line number Diff line
@@ -429,6 +429,42 @@ static int mt76u_get_rx_entry_len(u8 *data, u32 data_len) 
	return dma_len;

}



static struct sk_buff *

mt76u_build_rx_skb(void *data, int len, int buf_size)

{

	struct sk_buff *skb;



	if (SKB_WITH_OVERHEAD(buf_size) < MT_DMA_HDR_LEN + len) {

		struct page *page;



		/* slow path, not enough space for data and

		 * skb_shared_info

		 */

		skb = alloc_skb(MT_SKB_HEAD_LEN, GFP_ATOMIC);

		if (!skb)

			return NULL;



		skb_put_data(skb, data + MT_DMA_HDR_LEN, MT_SKB_HEAD_LEN);

		data += (MT_DMA_HDR_LEN + MT_SKB_HEAD_LEN);

		page = virt_to_head_page(data);

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

				page, data - page_address(page),

				len - MT_SKB_HEAD_LEN, buf_size);



		return skb;

	}



	/* fast path */

	skb = build_skb(data, buf_size);

	if (!skb)

		return NULL;



	skb_reserve(skb, MT_DMA_HDR_LEN);

	__skb_put(skb, len);



	return skb;

}



static int

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

{
@@ -446,19 +482,11 @@ mt76u_process_rx_entry(struct mt76_dev *dev, struct urb *urb) 
		return 0;



	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)) {

		dev_err_ratelimited(dev->dev, "rx data too big %d\n", data_len);

		return 0;

	}



	skb = build_skb(data, q->buf_size);

	skb = mt76u_build_rx_skb(data, data_len, q->buf_size);

	if (!skb)

		return 0;



	skb_reserve(skb, MT_DMA_HDR_LEN);

	__skb_put(skb, data_len);

	len -= data_len;



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

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

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

CRA Git | Maintained and supported by SUSTech CRA and CCSE