Upcoming SDIO support may sleep in the read/write handlers. Switch
all users of rtw_iterate_stas_atomic() which are either reading or
writing a register to rtw_iterate_stas().
Signed-off-by: Martin Blumenstingl <[email protected]>
---
drivers/net/wireless/realtek/rtw88/mac80211.c | 2 +-
drivers/net/wireless/realtek/rtw88/main.c | 2 +-
drivers/net/wireless/realtek/rtw88/phy.c | 4 ++--
drivers/net/wireless/realtek/rtw88/util.h | 2 ++
drivers/net/wireless/realtek/rtw88/wow.c | 2 +-
5 files changed, 7 insertions(+), 5 deletions(-)
diff --git a/drivers/net/wireless/realtek/rtw88/mac80211.c b/drivers/net/wireless/realtek/rtw88/mac80211.c
index 6f5629852416..7650a1ca0e9e 100644
--- a/drivers/net/wireless/realtek/rtw88/mac80211.c
+++ b/drivers/net/wireless/realtek/rtw88/mac80211.c
@@ -721,7 +721,7 @@ static void rtw_ra_mask_info_update(struct rtw_dev *rtwdev,
br_data.rtwdev = rtwdev;
br_data.vif = vif;
br_data.mask = mask;
- rtw_iterate_stas_atomic(rtwdev, rtw_ra_mask_info_update_iter, &br_data);
+ rtw_iterate_stas(rtwdev, rtw_ra_mask_info_update_iter, &br_data);
}
static int rtw_ops_set_bitrate_mask(struct ieee80211_hw *hw,
diff --git a/drivers/net/wireless/realtek/rtw88/main.c b/drivers/net/wireless/realtek/rtw88/main.c
index 207161a8f5bd..6e0d25f0afe3 100644
--- a/drivers/net/wireless/realtek/rtw88/main.c
+++ b/drivers/net/wireless/realtek/rtw88/main.c
@@ -577,7 +577,7 @@ static void __fw_recovery_work(struct rtw_dev *rtwdev)
rcu_read_lock();
rtw_iterate_keys_rcu(rtwdev, NULL, rtw_reset_key_iter, rtwdev);
rcu_read_unlock();
- rtw_iterate_stas_atomic(rtwdev, rtw_reset_sta_iter, rtwdev);
+ rtw_iterate_stas(rtwdev, rtw_reset_sta_iter, rtwdev);
rtw_iterate_vifs(rtwdev, rtw_reset_vif_iter, rtwdev);
rtw_enter_ips(rtwdev);
}
diff --git a/drivers/net/wireless/realtek/rtw88/phy.c b/drivers/net/wireless/realtek/rtw88/phy.c
index 569dd3cfde35..8f2827ecb514 100644
--- a/drivers/net/wireless/realtek/rtw88/phy.c
+++ b/drivers/net/wireless/realtek/rtw88/phy.c
@@ -240,7 +240,7 @@ static void rtw_phy_stat_rssi(struct rtw_dev *rtwdev)
data.rtwdev = rtwdev;
data.min_rssi = U8_MAX;
- rtw_iterate_stas_atomic(rtwdev, rtw_phy_stat_rssi_iter, &data);
+ rtw_iterate_stas(rtwdev, rtw_phy_stat_rssi_iter, &data);
dm_info->pre_min_rssi = dm_info->min_rssi;
dm_info->min_rssi = data.min_rssi;
@@ -484,7 +484,7 @@ static void rtw_phy_ra_info_update(struct rtw_dev *rtwdev)
if (rtwdev->watch_dog_cnt & 0x3)
return;
- rtw_iterate_stas_atomic(rtwdev, rtw_phy_ra_info_update_iter, rtwdev);
+ rtw_iterate_stas(rtwdev, rtw_phy_ra_info_update_iter, rtwdev);
}
static u32 rtw_phy_get_rrsr_mask(struct rtw_dev *rtwdev, u8 rate_idx)
diff --git a/drivers/net/wireless/realtek/rtw88/util.h b/drivers/net/wireless/realtek/rtw88/util.h
index 0c23b5069be0..b0dfadf8b82a 100644
--- a/drivers/net/wireless/realtek/rtw88/util.h
+++ b/drivers/net/wireless/realtek/rtw88/util.h
@@ -13,6 +13,8 @@ struct rtw_dev;
#define rtw_iterate_vifs_atomic(rtwdev, iterator, data) \
ieee80211_iterate_active_interfaces_atomic(rtwdev->hw, \
IEEE80211_IFACE_ITER_NORMAL, iterator, data)
+#define rtw_iterate_stas(rtwdev, iterator, data) \
+ ieee80211_iterate_stations(rtwdev->hw, iterator, data)
#define rtw_iterate_stas_atomic(rtwdev, iterator, data) \
ieee80211_iterate_stations_atomic(rtwdev->hw, iterator, data)
#define rtw_iterate_keys(rtwdev, vif, iterator, data) \
diff --git a/drivers/net/wireless/realtek/rtw88/wow.c b/drivers/net/wireless/realtek/rtw88/wow.c
index fc9544f4e5e4..9c4050d4c6e2 100644
--- a/drivers/net/wireless/realtek/rtw88/wow.c
+++ b/drivers/net/wireless/realtek/rtw88/wow.c
@@ -429,7 +429,7 @@ static void rtw_wow_fw_media_status(struct rtw_dev *rtwdev, bool connect)
data.rtwdev = rtwdev;
data.connect = connect;
- rtw_iterate_stas_atomic(rtwdev, rtw_wow_fw_media_status_iter, &data);
+ rtw_iterate_stas(rtwdev, rtw_wow_fw_media_status_iter, &data);
}
static void rtw_wow_config_pno_rsvd_page(struct rtw_dev *rtwdev,
--
2.32.0
> -----Original Message-----
> From: Martin Blumenstingl [mailto:[email protected]]
> Sent: Monday, July 26, 2021 5:51 AM
> To: Johannes Berg; Pkshih
> Cc: [email protected]; [email protected]; [email protected];
> [email protected]; [email protected]; Neo Jou; Jernej Skrabec
> Subject: Re: [PATCH RFC v1 3/7] rtw88: Use rtw_iterate_stas where the iterator reads or writes registers
>
> Hi Johannes, Hi Ping-Ke,
>
> On Mon, Jul 19, 2021 at 8:36 AM Johannes Berg <[email protected]> wrote:
> >
> > On Sat, 2021-07-17 at 22:40 +0200, Martin Blumenstingl wrote:
> > >
> > > --- a/drivers/net/wireless/realtek/rtw88/mac80211.c
> > > +++ b/drivers/net/wireless/realtek/rtw88/mac80211.c
> > > @@ -721,7 +721,7 @@ static void rtw_ra_mask_info_update(struct rtw_dev *rtwdev,
> > > br_data.rtwdev = rtwdev;
> > > br_data.vif = vif;
> > > br_data.mask = mask;
> > > - rtw_iterate_stas_atomic(rtwdev, rtw_ra_mask_info_update_iter, &br_data);
> > > + rtw_iterate_stas(rtwdev, rtw_ra_mask_info_update_iter, &br_data);
> >
> > And then you pretty much immediately break that invariant here, namely
> > that you're calling this within the set_bitrate_mask() method called by
> > mac80211.
> you are right, I was not aware of this
>
> > That's not actually fundamentally broken today, but it does *severely*
> > restrict what we can do in mac80211 wrt. locking, and I really don't
> > want to keep the dozen or so locks forever, this needs simplification
> > because clearly we don't even know what should be under what lock.
> To me it's also not clear what the goal of the whole locking is.
> The lock in ieee80211_iterate_stations_atomic is obviously for the
> mac80211-internal state-machine
> But I *believe* that there's a second purpose (rtw88 specific) -
> here's my understanding of that part:
> - rtw_sta_info contains a "mac_id" which is an identifier for a
> specific station used by the rtw88 driver and is shared with the
> firmware
> - rtw_ops_sta_{add,remove} uses rtwdev->mutex to protect the rtw88
> side of this "mac_id" identifier
> - (for some reason rtw_update_sta_info doesn't use rtwdev->mutex)
I am thinking rtw88 needs to maintain sta and vif lists itself, and
these lists are also protected by rtwdev->mutex. When rtw88 wants to
iterate all sta/vif, it holds rtwdev->mutex to do list_for_each_entry.
No need to hold mac80211 locks.
>
> So now I am wondering if the ieee80211_iterate_stations_atomic lock is
> also used to protect any modifications to rtw_sta_info.
> Ping-Ke, I am wondering if the attached patch (untested - to better
> demonstrate what I want to say) would:
> - allow us to move the register write outside of
> ieee80211_iterate_stations_atomic
> - mean we can keep ieee80211_iterate_stations_atomic (instead of the
> non-atomic variant)
> - protect the code managing the "mac_id" with rtwdev->mutex consistently
I think your attached patch can work well.
>
> > The other cases look OK, it's being called from outside contexts
> > (wowlan, etc.)
> Thanks for reviewing this Johannes!
>
--
Ping-Ke