Subject: Re: linux-next: manual merge of the tip tree with the wireless tree

From: "Paul E. McKenney" <[email-masked]>
Date: Tue, 17 May 2011 00:05:58 -0700

Hello!

One of these is mine in -tip (0744371aeb).  Please let me know what
I should be doing about it.

							Thanx, Paul

On Tue, May 17, 2011 at 01:14:17PM +1000, Stephen Rothwell wrote:
> Hi all,
> 
> Today's linux-next merge of the tip tree got a conflict in
> net/mac80211/agg-tx.c between commit ec034b208dc8 ("mac80211: fix TX
> a-MPDU locking") from the wireless tree and commit 0744371aeba7
> ("net,rcu: convert call_rcu(kfree_tid_tx) to kfree_rcu()") from the tip
> tree.
> 
> Just context changes.  I fixed it up (see below) and can carry the fix as
> necessary.
> -- 
> Cheers,
> Stephen Rothwell                    [email-masked]
> 
> diff --cc net/mac80211/agg-tx.c
> index cd5125f,53defaf..0000000
> --- a/net/mac80211/agg-tx.c
> +++ b/net/mac80211/agg-tx.c
> @@@ -136,22 -136,6 +136,14 @@@ void ieee80211_send_bar(struct ieee8021
>   	ieee80211_tx_skb(sdata, skb);
>   }
>   
>  +void ieee80211_assign_tid_tx(struct sta_info *sta, int tid,
>  +			     struct tid_ampdu_tx *tid_tx)
>  +{
>  +	lockdep_assert_held(&sta->ampdu_mlme.mtx);
>  +	lockdep_assert_held(&sta->lock);
>  +	rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], tid_tx);
>  +}
>  +
> - static void kfree_tid_tx(struct rcu_head *rcu_head)
> - {
> - 	struct tid_ampdu_tx *tid_tx =
> - 	    container_of(rcu_head, struct tid_ampdu_tx, rcu_head);
> - 
> - 	kfree(tid_tx);
> - }
> - 
>   int ___ieee80211_stop_tx_ba_session(struct sta_info *sta, u16 tid,
>   				    enum ieee80211_back_parties initiator,
>   				    bool tx)
> @@@ -162,19 -146,16 +154,19 @@@
>   
>   	lockdep_assert_held(&sta->ampdu_mlme.mtx);
>   
>  -	if (!tid_tx)
>  -		return -ENOENT;
>  -
>   	spin_lock_bh(&sta->lock);
>   
>  +	tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
>  +	if (!tid_tx) {
>  +		spin_unlock_bh(&sta->lock);
>  +		return -ENOENT;
>  +	}
>  +
>   	if (test_bit(HT_AGG_STATE_WANT_START, &tid_tx->state)) {
>   		/* not even started yet! */
>  -		rcu_assign_pointer(sta->ampdu_mlme.tid_tx[tid], NULL);
>  +		ieee80211_assign_tid_tx(sta, tid, NULL);
>   		spin_unlock_bh(&sta->lock);
> - 		call_rcu(&tid_tx->rcu_head, kfree_tid_tx);
> + 		kfree_rcu(tid_tx, rcu_head);
>   		return 0;
>   	}
>