RE: [PATCH v2 2/2] wifi: rtw88: use ieee80211_purge_tx_queue() to purge TX skb

[Ping-Ke Shih <pkshih@realtek.com>]

Ladislav Michl <oss-lists@triops.cz> wrote:
> On Wed, Nov 06, 2024 at 03:43:24AM +0000, Ping-Ke Shih wrote:
> > Ladislav Michl <oss-lists@triops.cz> wrote:
> > > On Thu, Aug 22, 2024 at 09:42:55AM +0800, Ping-Ke Shih wrote:
> > > > When removing kernel modules by:
> > > >    rmmod rtw88_8723cs rtw88_8703b rtw88_8723x rtw88_sdio rtw88_core
> > > >
> > > > Driver uses skb_queue_purge() to purge TX skb, but not report tx status
> > > > causing "Have pending ack frames!" warning. Use ieee80211_purge_tx_queue()
> > > > to correct this.
> > > >
> > > > Since ieee80211_purge_tx_queue() doesn't take locks, to prevent racing
> > > > between TX work and purge TX queue, flush and destroy TX work in advance.
> > >
> > > A the very same problem exists in 6.1 kernel series, where this patch
> > > becomes oneliner:
> >
> > linux-6.1.y branch doesn't have patch that exports ieee80211_purge_tx_queue().
> 
> Sure, but that one applies with a little fuzz.
> 
> > > ---
> > >  drivers/net/wireless/realtek/rtw88/main.c | 2 +-
> > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/net/wireless/realtek/rtw88/main.c b/drivers/net/wireless/realtek/rtw88/main.c
> > > index 81f3112923f1..d7d4b0f05da9 100644
> > > --- a/drivers/net/wireless/realtek/rtw88/main.c
> > > +++ b/drivers/net/wireless/realtek/rtw88/main.c
> > > @@ -2145,7 +2145,7 @@ void rtw_core_deinit(struct rtw_dev *rtwdev)
> > >
> > >         destroy_workqueue(rtwdev->tx_wq);
> > >         spin_lock_irqsave(&rtwdev->tx_report.q_lock, flags);
> > > -       skb_queue_purge(&rtwdev->tx_report.queue);
> > > +       ieee80211_purge_tx_queue(rtwdev->hw, &rtwdev->tx_report.queue);
> > >         skb_queue_purge(&rtwdev->coex.queue);
> > >         spin_unlock_irqrestore(&rtwdev->tx_report.q_lock, flags);
> > >
> >
> > Seemingly, we need below also?
> 
> Perhaps I was lucky enough I never hit it here, but for a sake of completeness
> it should be there as well.
> 
> > diff --git a/drivers/net/wireless/realtek/rtw88/tx.c b/drivers/net/wireless/realtek/rtw88/tx.c
> > index 6ed470dd6f22..224678b9c38b 100644
> > --- a/drivers/net/wireless/realtek/rtw88/tx.c
> > +++ b/drivers/net/wireless/realtek/rtw88/tx.c
> > @@ -188,7 +188,7 @@ void rtw_tx_report_purge_timer(struct timer_list *t)
> >         rtw_warn(rtwdev, "failed to get tx report from firmware\n");
> >
> >         spin_lock_irqsave(&tx_report->q_lock, flags);
> > -       skb_queue_purge(&tx_report->queue);
> > +       ieee80211_purge_tx_queue(&tx_report->queue);
> >         spin_unlock_irqrestore(&tx_report->q_lock, flags);
> >  }
> >
> > Have you seen "Have pending ack frames!" in your side?
> 
> Yes.
> 
> > If so, use above changes to verify again on the latest kernel, and send a patch?
> 
> Do you mean to send a patch against linux-6.1.y stable tree? I can see your
> patch in wireless-next only, so I do not think sending it to stable now would
> work. But in general, having this fix in the stable trees is a good idea.

I meant to send a patch to wireless-next. After it gets merged, send another
backport patchset related to the warning to 6.1 and 6.6.