RE: [PATCH 2/2] wifi: rtw88: usb: Enable RX aggregation for 8821au/8812au

[Ping-Ke Shih <pkshih@realtek.com>]

Bitterblue Smith <rtl8821cerfe2@gmail.com> wrote:
>> 
> USB RX aggregation improves the RX speed on certain ARM systems, like
> the NanoPi NEO Core2. With RTL8811AU, before: 30 Mbps, after: 224 Mbps.
> 
> The out-of-tree driver uses aggregation size of 7 in USB 3 mode, but
> that doesn't work here. rtw88 advertises support for receiving AMSDU
> in AMPDU, so the AP sends larger frames, up to ~5100 bytes. With a size
> of 7 RTL8812AU frequently tries to aggregate more frames than will fit
> in 32768 bytes. Use a size of 6 instead.
> 
> Signed-off-by: Bitterblue Smith <rtl8821cerfe2@gmail.com>
> ---
>  drivers/net/wireless/realtek/rtw88/usb.c | 30 ++++++++++++++++++++++++
>  1 file changed, 30 insertions(+)
> 
> diff --git a/drivers/net/wireless/realtek/rtw88/usb.c b/drivers/net/wireless/realtek/rtw88/usb.c
> index 752bca05b9af..9172af63500b 100644
> --- a/drivers/net/wireless/realtek/rtw88/usb.c
> +++ b/drivers/net/wireless/realtek/rtw88/usb.c
> @@ -790,6 +790,32 @@ static void rtw_usb_dynamic_rx_agg_v1(struct rtw_dev *rtwdev, bool enable)
>         rtw_write16(rtwdev, REG_RXDMA_AGG_PG_TH, val16);
>  }
> 
> +static void rtw_usb_dynamic_rx_agg_v2(struct rtw_dev *rtwdev, bool enable)
> +{
> +       struct rtw_usb *rtwusb = rtw_get_usb_priv(rtwdev);
> +       u8 size, timeout;
> +       u16 val16;
> +

How about a shortcut?

if (!enable) {
	size = 0x0;
	timeout = 0x1;

	goto rx_agg;
}

> +       if (rtwusb->udev->speed == USB_SPEED_SUPER) {
> +               size = 0x6;
> +               timeout = 0x1a;
> +       } else {
> +               size = 0x5;
> +               timeout = 0x20;
> +       }
> +
> +       if (!enable) {
> +               size = 0x0;
> +               timeout = 0x1;
> +       }
> +

rx_agg:

> +       val16 = u16_encode_bits(size, BIT_RXDMA_AGG_PG_TH) |
> +               u16_encode_bits(timeout, BIT_DMA_AGG_TO_V1);
> +
> +       rtw_write16(rtwdev, REG_RXDMA_AGG_PG_TH, val16);
> +       rtw_write8_set(rtwdev, REG_TXDMA_PQ_MAP, BIT_RXDMA_AGG_EN);
> +}
> +
>  static void rtw_usb_dynamic_rx_agg(struct rtw_dev *rtwdev, bool enable)
>  {
>         switch (rtwdev->chip->id) {
> @@ -798,6 +824,10 @@ static void rtw_usb_dynamic_rx_agg(struct rtw_dev *rtwdev, bool enable)
>         case RTW_CHIP_TYPE_8821C:
>                 rtw_usb_dynamic_rx_agg_v1(rtwdev, enable);
>                 break;
> +       case RTW_CHIP_TYPE_8821A:
> +       case RTW_CHIP_TYPE_8812A:
> +               rtw_usb_dynamic_rx_agg_v2(rtwdev, enable);
> +               break;
>         case RTW_CHIP_TYPE_8723D:
>                 /* Doesn't like aggregation. */
>                 break;
> --
> 2.47.0