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

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

Ho Jie Feng <hjf3108@gmail.com> 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@gmail.com>

Acked-by is given, but some minor comments.

Acked-by: Ping-Ke Shih <pkshih@realtek.com>

> +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 ?

> +               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);
> +}
> +