| Message ID | 20221228133547.633797-4-martin.blumenstingl@googlemail.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Kalle Valo |
| Headers | show |
| Series | rtw88: Four fixes found while working on SDIO support | expand |
> -----Original Message----- > From: Martin Blumenstingl <martin.blumenstingl@googlemail.com> > Sent: Wednesday, December 28, 2022 9:36 PM > To: linux-wireless@vger.kernel.org > Cc: tony0620emma@gmail.com; kvalo@kernel.org; Ping-Ke Shih <pkshih@realtek.com>; tehuang@realtek.com; > s.hauer@pengutronix.de; netdev@vger.kernel.org; linux-kernel@vger.kernel.org; Martin Blumenstingl > <martin.blumenstingl@googlemail.com> > Subject: [PATCH 3/4] rtw88: Use rtw_iterate_vifs() for rtw_vif_watch_dog_iter() > > USB and (upcoming) SDIO support may sleep in the read/write handlers. > Make rtw_watch_dog_work() use rtw_iterate_vifs() to prevent "scheduling > while atomic" or "Voluntary context switch within RCU read-side > critical section!" warnings when accessing the registers using an SDIO > card (which is where this issue has been spotted in the real world but > it also affects USB cards). > > Fixes: 78d5bf925f30 ("wifi: rtw88: iterate over vif/sta list non-atomically") > Suggested-by: Ping-Ke Shih <pkshih@realtek.com> > Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Reviewed-by: Ping-Ke Shih <pkshih@realtek.com> > --- > drivers/net/wireless/realtek/rtw88/main.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/wireless/realtek/rtw88/main.c b/drivers/net/wireless/realtek/rtw88/main.c > index 888427cf3bdf..b2e78737bd5d 100644 > --- a/drivers/net/wireless/realtek/rtw88/main.c > +++ b/drivers/net/wireless/realtek/rtw88/main.c > @@ -241,8 +241,10 @@ static void rtw_watch_dog_work(struct work_struct *work) > rtw_phy_dynamic_mechanism(rtwdev); > > data.rtwdev = rtwdev; > - /* use atomic version to avoid taking local->iflist_mtx mutex */ > - rtw_iterate_vifs_atomic(rtwdev, rtw_vif_watch_dog_iter, &data); > + /* rtw_iterate_vifs internally uses an atomic iterator which is needed > + * to avoid taking local->iflist_mtx mutex > + */ > + rtw_iterate_vifs(rtwdev, rtw_vif_watch_dog_iter, &data); > > /* fw supports only one station associated to enter lps, if there are > * more than two stations associated to the AP, then we can not enter > -- > 2.39.0
diff --git a/drivers/net/wireless/realtek/rtw88/main.c b/drivers/net/wireless/realtek/rtw88/main.c index 888427cf3bdf..b2e78737bd5d 100644 --- a/drivers/net/wireless/realtek/rtw88/main.c +++ b/drivers/net/wireless/realtek/rtw88/main.c @@ -241,8 +241,10 @@ static void rtw_watch_dog_work(struct work_struct *work) rtw_phy_dynamic_mechanism(rtwdev); data.rtwdev = rtwdev; - /* use atomic version to avoid taking local->iflist_mtx mutex */ - rtw_iterate_vifs_atomic(rtwdev, rtw_vif_watch_dog_iter, &data); + /* rtw_iterate_vifs internally uses an atomic iterator which is needed + * to avoid taking local->iflist_mtx mutex + */ + rtw_iterate_vifs(rtwdev, rtw_vif_watch_dog_iter, &data); /* fw supports only one station associated to enter lps, if there are * more than two stations associated to the AP, then we can not enter
USB and (upcoming) SDIO support may sleep in the read/write handlers. Make rtw_watch_dog_work() use rtw_iterate_vifs() to prevent "scheduling while atomic" or "Voluntary context switch within RCU read-side critical section!" warnings when accessing the registers using an SDIO card (which is where this issue has been spotted in the real world but it also affects USB cards). Fixes: 78d5bf925f30 ("wifi: rtw88: iterate over vif/sta list non-atomically") Suggested-by: Ping-Ke Shih <pkshih@realtek.com> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> --- drivers/net/wireless/realtek/rtw88/main.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)