Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 29b68a92 authored by Jian-Hong Pan's avatar Jian-Hong Pan Committed by Kalle Valo
Browse files

rtw88: pci: Use DMA sync instead of remapping in RX ISR 



Since each skb in RX ring is reused instead of new allocation, we can
treat the DMA in a more efficient way by DMA synchronization.

Signed-off-by: default avatarJian-Hong Pan <jian-hong@endlessm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarKalle Valo <kvalo@codeaurora.org>
parent ee6db78f

drivers/net/wireless/realtek/rtw88/pci.c

+21 −3
Original line number Diff line number Diff line
@@ -206,6 +206,23 @@ static int rtw_pci_reset_rx_desc(struct rtw_dev *rtwdev, struct sk_buff *skb, 
	return 0;

}



static void rtw_pci_sync_rx_desc_device(struct rtw_dev *rtwdev, dma_addr_t dma,

					struct rtw_pci_rx_ring *rx_ring,

					u32 idx, u32 desc_sz)

{

	struct device *dev = rtwdev->dev;

	struct rtw_pci_rx_buffer_desc *buf_desc;

	int buf_sz = RTK_PCI_RX_BUF_SIZE;



	dma_sync_single_for_device(dev, dma, buf_sz, DMA_FROM_DEVICE);



	buf_desc = (struct rtw_pci_rx_buffer_desc *)(rx_ring->r.head +

						     idx * desc_sz);

	memset(buf_desc, 0, sizeof(*buf_desc));

	buf_desc->buf_size = cpu_to_le16(RTK_PCI_RX_BUF_SIZE);

	buf_desc->dma = cpu_to_le32(dma);

}



static int rtw_pci_init_rx_ring(struct rtw_dev *rtwdev,

				struct rtw_pci_rx_ring *rx_ring,

				u8 desc_size, u32 len)
@@ -784,8 +801,8 @@ static void rtw_pci_rx_isr(struct rtw_dev *rtwdev, struct rtw_pci *rtwpci, 
		rtw_pci_dma_check(rtwdev, ring, cur_rp);

		skb = ring->buf[cur_rp];

		dma = *((dma_addr_t *)skb->cb);

		pci_unmap_single(rtwpci->pdev, dma, RTK_PCI_RX_BUF_SIZE,

				 PCI_DMA_FROMDEVICE);

		dma_sync_single_for_cpu(rtwdev->dev, dma, RTK_PCI_RX_BUF_SIZE,

					DMA_FROM_DEVICE);

		rx_desc = skb->data;

		chip->ops->query_rx_desc(rtwdev, rx_desc, &pkt_stat, &rx_status);
@@ -820,7 +837,8 @@ static void rtw_pci_rx_isr(struct rtw_dev *rtwdev, struct rtw_pci *rtwpci, 


next_rp:

		/* new skb delivered to mac80211, re-enable original skb DMA */

		rtw_pci_reset_rx_desc(rtwdev, skb, ring, cur_rp, buf_desc_sz);

		rtw_pci_sync_rx_desc_device(rtwdev, dma, ring, cur_rp,

					    buf_desc_sz);



		/* host read next element in ring */

		if (++cur_rp >= ring->r.len)