Johannes Berg <johannes@xxxxxxxxxxxxxxxx> writes:
>> +static int invoke_tx_handlers_late(struct ieee80211_tx_data *tx);
>> +static bool ieee80211_xmit_fast_finish(struct ieee80211_sub_if_data *sdata,
>> + struct sta_info *sta, u8 pn_offs,
>> + struct ieee80211_key_conf *key_conf,
>> + struct sk_buff *skb);
>> +
>
> I'm not very happy with this - I think you should do some
> refactoring/code move in a separate prior patch to avoid this.
Noted, will do.
>> + 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);
>> + u8 pn_offs = 0;
>>
>> - 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;
>> + if (info->control.hw_key)
>> + pn_offs = ieee80211_hdrlen(hdr->frame_control);
>
> Not very happy with this either - the fast-xmit path explicitly tries
> to avoid all these calculations.
Well, the TXQ already adds a lot of other overhead (hashing on the
packet header, for one), so my guess would be that this would be
negligible compared to all that?
> I suppose I don't have to care all that much about the TXQs, but ...
>
> Then again, adding a field in the skb->cb for the sake of this? No,
> not really either.
So that's a "keep it", then? :)
>> + ieee80211_xmit_fast_finish(sta->sdata, sta, pn_offs,
>> + info->control.hw_key, skb);
>
> I don't see how keeping the info->control.hw_key pointer across the
> TXQ/FQ/Codel queueing isn't a potential bug? Probably one that already
> exists in your code today, before this patch, of course.
You mean the key could get removed from the hardware while the packet
was queued? Can certainly add a check for that. Under what conditions
does that happen? Does it make sense to try to recover from it (I guess
by calling tx_h_select_key), or is it rare enough that giving up and
dropping the packet makes more sense?
>> + } else {
>> + struct ieee80211_tx_data tx = { };
>> +
>> + __skb_queue_head_init(&tx.skbs);
>> + tx.local = local;
>> + tx.skb = skb;
>
> an empty initializer is weird - why not at least move local/skb
> initializations into it? Even txq->sta, I guess, since you can assign
> txq->sta either way.
Yup, makes sense. Noted.
>> - CALL_TXH(ieee80211_tx_h_select_key);
>> +
>> if (!ieee80211_hw_check(&tx->local->hw, HAS_RATE_CONTROL))
>> CALL_TXH(ieee80211_tx_h_rate_ctrl);
> [...]
>> if (unlikely(info->flags & IEEE80211_TX_INTFL_RETRANSMISSION)) {
>> __skb_queue_tail(&tx->skbs, tx->skb);
>> tx->skb = NULL;
>> goto txh_done;
>> }
>>
>> + CALL_TXH(ieee80211_tx_h_select_key);
>
> What happens for the IEEE80211_TX_INTFL_RETRANSMISSION packets wrt.
> key selection? Why is it OK to change this?
You're right, that's an oversight on my part. Will fix.
-Toke
