lkml.org 
[lkml]   [2019]   [Jul]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH v2 2/2] rtw88: pci: Use DMA sync instead of remapping in RX ISR
    On Tue, Jul 09, 2019 at 06:21:01PM +0800, Jian-Hong Pan wrote:
    > 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: Jian-Hong Pan <jian-hong@endlessm.com>
    > ---
    > drivers/net/wireless/realtek/rtw88/pci.c | 35 ++++++++++++++++++++++--
    > 1 file changed, 32 insertions(+), 3 deletions(-)
    >
    > diff --git a/drivers/net/wireless/realtek/rtw88/pci.c b/drivers/net/wireless/realtek/rtw88/pci.c
    > index e9fe3ad896c8..28ca76f71dfe 100644
    > --- a/drivers/net/wireless/realtek/rtw88/pci.c
    > +++ b/drivers/net/wireless/realtek/rtw88/pci.c
    > @@ -206,6 +206,35 @@ static int rtw_pci_reset_rx_desc(struct rtw_dev *rtwdev, struct sk_buff *skb,
    > return 0;
    > }
    >
    > +static int rtw_pci_sync_rx_desc_cpu(struct rtw_dev *rtwdev, dma_addr_t dma)
    > +{
    > + struct device *dev = rtwdev->dev;
    > + int buf_sz = RTK_PCI_RX_BUF_SIZE;
    > +
    > + dma_sync_single_for_cpu(dev, dma, buf_sz, PCI_DMA_FROMDEVICE);
    > +
    > + return 0;
    > +}

    No need to return a value from this helper. In fact I'm not even sure
    you need the helper at all. Also please use the DMA_FROM_DEVICE
    constant instead of the deprecated PCI variant.

    > +static int 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, PCI_DMA_FROMDEVICE);
    > +
    > + 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);
    > +
    > + return 0;
    > +}

    Same comment on the PCI constant and the return value here.

    \
     
     \ /
      Last update: 2019-07-09 18:16    [W:3.804 / U:0.244 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site