Re: [Make-wifi-fast] [PATCH v5] mac80211: Move reorder-sensitive TX handlers to after TXQ dequeue.

["Toke Høiland-Jørgensen" <toke@toke.dk>]

Jason Andryuk <jandryuk@gmail.com> writes:

> On Thu, Sep 1, 2016 at 12:03 PM, Toke Høiland-Jørgensen <toke@toke.dk> wrote:
>> @@ -1481,33 +1506,57 @@ struct sk_buff *ieee80211_tx_dequeue(struct ieee80211_hw *hw,
>>  {
>>         struct ieee80211_local *local = hw_to_local(hw);
>>         struct txq_info *txqi = container_of(txq, struct txq_info, txq);
>> -       struct ieee80211_hdr *hdr;
>>         struct sk_buff *skb = NULL;
>>         struct fq *fq = &local->fq;
>>         struct fq_tin *tin = &txqi->tin;
>> +       struct ieee80211_tx_info *info;
>>
>>         spin_lock_bh(&fq->lock);
>>
>>         if (test_bit(IEEE80211_TXQ_STOP, &txqi->flags))
>>                 goto out;
>>
>> +begin:
>>         skb = fq_tin_dequeue(fq, tin, fq_tin_dequeue_func);
>>         if (!skb)
>>                 goto out;
>>
>>         ieee80211_set_skb_vif(skb, txqi);
>>
>> -       hdr = (struct ieee80211_hdr *)skb->data;
>> -       if (txq->sta && ieee80211_is_data_qos(hdr->frame_control)) {
>> +       info = IEEE80211_SKB_CB(skb);
>> +       if (txq->sta && info->control.flags & IEEE80211_TX_CTRL_FAST_XMIT) {
>>                 struct sta_info *sta = container_of(txq->sta, struct sta_info,
>>                                                     sta);
>> -               struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
>> +               struct ieee80211_fast_tx *fast_tx;
>>
>> -               hdr->seq_ctrl = ieee80211_tx_next_seq(sta, txq->tid);
>> -               if (test_bit(IEEE80211_TXQ_AMPDU, &txqi->flags))
>> -                       info->flags |= IEEE80211_TX_CTL_AMPDU;
>> -               else
>> -                       info->flags &= ~IEEE80211_TX_CTL_AMPDU;
>> +               fast_tx = rcu_dereference(sta->fast_tx);
>> +               if (WARN_ON(!fast_tx)) {
>> +                       /* lost the fast_tx pointer while the packet was queued */
>> +                       ieee80211_free_txskb(hw, skb);
>> +                       goto begin;
>> +               }
>> +               ieee80211_xmit_fast_finish(sta->sdata, sta, fast_tx, skb, false);
>> +       } else {
>> +               struct ieee80211_tx_data tx = { };
>> +
>> +               __skb_queue_head_init(&tx.skbs);
>> +               tx.local = local;
>> +               if (txq->sta) {
>> +                       struct sta_info *sta = container_of(txq->sta,
>> +                                                           struct sta_info,
>> +                                                           sta);
>
> sta is unneeded give the assignment below?

Yeah, you're right. Think that was left over from a previous version.
Thanks for spotting it :)

-Toke