Re: [PATCH tip/core/rcu 01/12] rcu: Remove rcu_swap_protected()

[Paul E. McKenney]

On Tue, Dec 10, 2019 at 07:51:22PM -0800, Paul E. McKenney wrote:
> On Tue, Dec 10, 2019 at 10:35:49PM -0500, Martin K. Petersen wrote:
> > 
> > Paul,
> > 
> > > Now that the calls to rcu_swap_protected() have been replaced by
> > > rcu_replace_pointer(), this commit removes rcu_swap_protected().
> > 
> > It appears there are two callers remaining in Linus' master. Otherwise
> > looks good to me.
> 
> I did queue a fix for one of them, and thank you for calling my
> attention to the new one.  This commit should hit -next soon, so
> hopefully this will discourage further additions.  ;-)
> 
> > Reviewed-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
> 
> Thank you!

And here is the patch for the new one.

							Thanx, Paul

------------------------------------------------------------------------

commit 10699d92c906707d679e28b099cd798a519b4f51
Author: Paul E. McKenney <paulmck@xxxxxxxxxx>
Date:   Wed Dec 11 10:30:21 2019 -0800

    wireless/mediatek: Replace rcu_swap_protected() with rcu_replace_pointer()
    
    This commit replaces the use of rcu_swap_protected() with the more
    intuitively appealing rcu_replace_pointer() as a step towards removing
    rcu_swap_protected().
    
    Link: https://lore.kernel.org/lkml/CAHk-=wiAsJLw1egFEE=Z7-GGtM6wcvtyytXZA1+BHqta4gg6Hw@xxxxxxxxxxxxxx/
    Reported-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
    Reported-by: "Martin K. Petersen" <martin.petersen@xxxxxxxxxx>
    Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
    Cc: Felix Fietkau <nbd@xxxxxxxx>
    Cc: Lorenzo Bianconi <lorenzo.bianconi83@xxxxxxxxx>
    Cc: Ryder Lee <ryder.lee@xxxxxxxxxxxx>
    Cc: Roy Luo <royluo@xxxxxxxxxx>
    Cc: Kalle Valo <kvalo@xxxxxxxxxxxxxx>
    Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
    Cc: Matthias Brugger <matthias.bgg@xxxxxxxxx>
    Cc: <linux-wireless@xxxxxxxxxxxxxxx>
    Cc: <netdev@xxxxxxxxxxxxxxx>
    Cc: <linux-arm-kernel@xxxxxxxxxxxxxxxxxxx>
    Cc: <linux-mediatek@xxxxxxxxxxxxxxxxxxx>

diff --git a/drivers/net/wireless/mediatek/mt76/agg-rx.c b/drivers/net/wireless/mediatek/mt76/agg-rx.c
index 53b5a4b..80986ce 100644
--- a/drivers/net/wireless/mediatek/mt76/agg-rx.c
+++ b/drivers/net/wireless/mediatek/mt76/agg-rx.c
@@ -281,8 +281,8 @@ void mt76_rx_aggr_stop(struct mt76_dev *dev, struct mt76_wcid *wcid, u8 tidno)
 {
 	struct mt76_rx_tid *tid = NULL;
 
-	rcu_swap_protected(wcid->aggr[tidno], tid,
-			   lockdep_is_held(&dev->mutex));
+	tid = rcu_swap_protected(wcid->aggr[tidno], tid,
+				 lockdep_is_held(&dev->mutex));
 	if (tid) {
 		mt76_rx_aggr_shutdown(dev, tid);
 		kfree_rcu(tid, rcu_head);