Re: [PATCH 04/13] wifi: mt76: mt7615: rely on shared sta_poll_list and sta_poll_lock

[Lorenzo Bianconi <lorenzo@kernel.org>]

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> Hi,

Hi,

> 
> On 5/29/23 13:40, Lorenzo Bianconi wrote:
> > Rely on sta_poll_list and sta_poll_lock fields in mt76_dev structure
> > and get rid of private copies.
> > 
> > Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
> > ---
> >  .../net/wireless/mediatek/mt76/mt7615/init.c  |  2 --
> >  .../net/wireless/mediatek/mt76/mt7615/mac.c   | 19 ++++++++++---------
> >  .../net/wireless/mediatek/mt76/mt7615/main.c  |  8 ++++----
> >  .../wireless/mediatek/mt76/mt7615/mt7615.h    |  3 ---
> >  4 files changed, 14 insertions(+), 18 deletions(-)
> > 
> > diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/init.c b/drivers/net/wireless/mediatek/mt76/mt7615/init.c
> > index 621e69f07e3c..155931978ed8 100644
> > --- a/drivers/net/wireless/mediatek/mt76/mt7615/init.c
> > +++ b/drivers/net/wireless/mediatek/mt76/mt7615/init.c
> > @@ -626,8 +626,6 @@ void mt7615_init_device(struct mt7615_dev *dev)
> >  	INIT_DELAYED_WORK(&dev->coredump.work, mt7615_coredump_work);
> >  	skb_queue_head_init(&dev->phy.scan_event_list);
> >  	skb_queue_head_init(&dev->coredump.msg_list);
> > -	INIT_LIST_HEAD(&dev->sta_poll_list);
> > -	spin_lock_init(&dev->sta_poll_lock);
> >  	init_waitqueue_head(&dev->reset_wait);
> >  	init_waitqueue_head(&dev->phy.roc_wait);
> >  
> > diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/mac.c b/drivers/net/wireless/mediatek/mt76/mt7615/mac.c
> > index d90378a30d15..a6d267c56dd4 100644
> > --- a/drivers/net/wireless/mediatek/mt76/mt7615/mac.c
> > +++ b/drivers/net/wireless/mediatek/mt76/mt7615/mac.c
> > @@ -387,10 +387,11 @@ static int mt7615_mac_fill_rx(struct mt7615_dev *dev, struct sk_buff *skb)
> >  		struct mt7615_sta *msta;
> >  
> >  		msta = container_of(status->wcid, struct mt7615_sta, wcid);
> > -		spin_lock_bh(&dev->sta_poll_lock);
> > +		spin_lock_bh(&dev->mt76.sta_poll_lock);
> >  		if (list_empty(&msta->poll_list))
> > -			list_add_tail(&msta->poll_list, &dev->sta_poll_list);
> > -		spin_unlock_bh(&dev->sta_poll_lock);
> > +			list_add_tail(&msta->poll_list,
> > +				      &dev->mt76.sta_poll_list);
> > +		spin_unlock_bh(&dev->mt76.sta_poll_lock);
> >  	}
> >  
> >  	if (mt76_is_mmio(&dev->mt76) && (rxd0 & csum_mask) == csum_mask &&
> > @@ -905,9 +906,9 @@ void mt7615_mac_sta_poll(struct mt7615_dev *dev)
> >  	int i;
> >  
> >  	INIT_LIST_HEAD(&sta_poll_list);
> > -	spin_lock_bh(&dev->sta_poll_lock);
> > -	list_splice_init(&dev->sta_poll_list, &sta_poll_list);
> > -	spin_unlock_bh(&dev->sta_poll_lock);
> > +	spin_lock_bh(&dev->mt76.sta_poll_lock);
> > +	list_splice_init(&dev->mt76.sta_poll_list, &sta_poll_list);
> > +	spin_unlock_bh(&dev->mt76.sta_poll_lock);
> >  
> >  	while (!list_empty(&sta_poll_list)) {
> >  		bool clear = false;
> > @@ -1539,10 +1540,10 @@ static void mt7615_mac_add_txs(struct mt7615_dev *dev, void *data)
> >  	msta = container_of(wcid, struct mt7615_sta, wcid);
> >  	sta = wcid_to_sta(wcid);
> >  
> > -	spin_lock_bh(&dev->sta_poll_lock);
> > +	spin_lock_bh(&dev->mt76.sta_poll_lock);
> >  	if (list_empty(&msta->poll_list))
> > -		list_add_tail(&msta->poll_list, &dev->sta_poll_list);
> > -	spin_unlock_bh(&dev->sta_poll_lock);
> > +		list_add_tail(&msta->poll_list, &dev->mt76.sta_poll_list);
> > +	spin_unlock_bh(&dev->mt76.sta_poll_lock);
> >  
> >  	if (mt7615_mac_add_txs_skb(dev, msta, pid, txs_data))
> >  		goto out;
> > diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/main.c b/drivers/net/wireless/mediatek/mt76/mt7615/main.c
> > index ab4c1b4478aa..2a5462bd54c2 100644
> > --- a/drivers/net/wireless/mediatek/mt76/mt7615/main.c
> > +++ b/drivers/net/wireless/mediatek/mt76/mt7615/main.c
> > @@ -274,10 +274,10 @@ static void mt7615_remove_interface(struct ieee80211_hw *hw,
> >  
> >  	mt7615_mutex_release(dev);
> >  
> > -	spin_lock_bh(&dev->sta_poll_lock);
> > +	spin_lock_bh(&dev->mt76.sta_poll_lock);
> >  	if (!list_empty(&msta->poll_list))
> >  		list_del_init(&msta->poll_list);
> > -	spin_unlock_bh(&dev->sta_poll_lock);
> > +	spin_unlock_bh(&dev->mt76.sta_poll_lock);
> >  
> >  	mt76_packet_id_flush(&dev->mt76, &mvif->sta.wcid);
> >  }
> > @@ -677,10 +677,10 @@ void mt7615_mac_sta_remove(struct mt76_dev *mdev, struct ieee80211_vif *vif,
> >  	if (vif->type == NL80211_IFTYPE_STATION && !sta->tdls)
> >  		mt7615_mcu_add_bss_info(phy, vif, sta, false);
> >  
> > -	spin_lock_bh(&dev->sta_poll_lock);
> > +	spin_lock_bh(&mdev->sta_poll_lock);
> >  	if (!list_empty(&msta->poll_list))
> >  		list_del_init(&msta->poll_list);
> > -	spin_unlock_bh(&dev->sta_poll_lock);
> > +	spin_unlock_bh(&mdev->sta_poll_lock);
> >  
> >  	mt76_connac_power_save_sched(phy->mt76, &dev->pm);
> >  }
> > diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/mt7615.h b/drivers/net/wireless/mediatek/mt76/mt7615/mt7615.h
> > index 0381c53bc96a..7386495f8299 100644
> > --- a/drivers/net/wireless/mediatek/mt76/mt7615/mt7615.h
> > +++ b/drivers/net/wireless/mediatek/mt76/mt7615/mt7615.h
> > @@ -262,9 +262,6 @@ struct mt7615_dev {
> >  	wait_queue_head_t reset_wait;
> >  	u32 reset_state;
> >  
> > -	struct list_head sta_poll_list;
> > -	spinlock_t sta_poll_lock;
> > -
> >  	struct {
> >  		u8 n_pulses;
> >  		u32 period;
> 
> From code review on GitHub, you did not update to use the shared sta_poll_lock in line 919 and 921.

The fix below is not part of wireless-next yet:

commit 30bc32c7c1f975cc3c14e1c7dc437266311282cf
Author: Lorenzo Bianconi <lorenzo@kernel.org>
Date:   Wed May 24 16:39:32 2023 +0200

    wifi: mt76: mt7615: fix possible race in mt7615_mac_sta_poll

I will repost when it is merged in wireless-next/Felix's tree.

Regards,
Lorenzo

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