Re: [PATCH rtw-next 4/5] wifi: rtlwifi: rtl8192du: enable USB RX aggregation

[Jie Feng]

On Mon, 9 Nov 2026 at 08:44, Ping-Ke Shih <pkshih@xxxxxxxxxxx> wrote:
>
> Ho Jie Feng <hjf3108@xxxxxxxxx> wrote:
> > Allow RX aggregation of up to 48 pages of 128 bytes or 24 with two MACs.
>
> You can describe a little bit how you build separate skb, especially
> the last one.
>
> >
> > Test results (2.4 GHz):
> >    before after
> > TX 5.2    6.4
> > RX 27.1   32.0
> >
> > Signed-off-by: Ho Jie Feng <hjf3108@xxxxxxxxx>
>
> Acked-by is given, but some minor comments.
>
> Acked-by: Ping-Ke Shih <pkshih@xxxxxxxxxxx>
>
> > +void rtl92du_rx_segregate_hdl(struct ieee80211_hw *hw, struct sk_buff *skb,
> > +                             struct sk_buff_head *queue)
> > +{
> > +       struct rtl_priv *rtlpriv = rtl_priv(hw);
> > +       unsigned int offset = 0, pkt_size;
> > +       struct sk_buff *new_skb;
> > +       __le32 *rxdesc;
> > +
> > +       while (skb->len - offset >= RTL_RX_DESC_SIZE) {
> > +               rxdesc = (__le32 *)(skb->data + offset);
> > +               pkt_size = RTL_RX_DESC_SIZE +
> > +                          get_rx_desc_drv_info_size(rxdesc) *
> > +                          RX_DRV_INFO_SIZE_UNIT +
> > +                          get_rx_desc_shift(rxdesc) +
> > +                          get_rx_desc_pkt_len(rxdesc);
> > +
> > +               if (get_rx_desc_pkt_len(rxdesc) == 0 ||
> > +                   pkt_size > skb->len - offset) {
> > +                       rtl_dbg(rtlpriv, COMP_RECV, DBG_WARNING,
> > +                               "bad frame at %u of %u, size %u\n",
> > +                               offset, skb->len, pkt_size);
> > +                       break;
> > +               }
> > +
> > +               /* The last frame keeps the original skb. */
> > +               if (ALIGN(pkt_size, RTL92DU_RX_AGG_ALIGN) >= skb->len - offset) {
> > +                       skb_pull(skb, offset);
> > +                       skb_trim(skb, pkt_size);
> > +                       __skb_queue_tail(queue, skb);
> > +                       return;
> > +               }
> > +
> > +               new_skb = dev_alloc_skb(pkt_size + RTL92DU_RX_HEADROOM);
>
> What is the purpose of RTL92DU_RX_HEADROOM ?
This is for the radiotap header, like in usb.c.

I could drop it, or add comments or a commit description to describe it?

https://github.com/pkshih/rtw/blob/rtw-next/drivers/net/wireless/realtek/rtlwifi/usb.c#L582
> > +               if (!new_skb)
> > +                       break;
> > +               skb_reserve(new_skb, RTL92DU_RX_HEADROOM);
> > +               skb_put_data(new_skb, rxdesc, pkt_size);
> > +               __skb_queue_tail(queue, new_skb);
> > +
> > +               offset += ALIGN(pkt_size, RTL92DU_RX_AGG_ALIGN);
> > +       }
> > +
> > +       dev_kfree_skb_any(skb);
> > +}
> > +
>
>