[PATCH 4/4] rtw88: Use non-atomic rtw_iterate_stas() in rtw_ra_mask_info_update()

From: Martin Blumenstingl
Date: Wed Dec 28 2022 - 08:37:23 EST


USB and (upcoming) SDIO support may sleep in the read/write handlers.
Use non-atomic rtw_iterate_stas() in rtw_ra_mask_info_update() because
the iterator function rtw_ra_mask_info_update_iter() needs to read and
write registers from within rtw_update_sta_info(). Using the non-atomic
iterator ensures that we can sleep during USB and SDIO register reads
and writes. This fixes "scheduling while atomic" or "Voluntary context
switch within RCU read-side critical section!" warnings as seen by SDIO
card users (but it also affects USB cards).

Fixes: 78d5bf925f30 ("wifi: rtw88: iterate over vif/sta list non-atomically")
Suggested-by: Ping-Ke Shih <pkshih@xxxxxxxxxxx>
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>
---
drivers/net/wireless/realtek/rtw88/mac80211.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/realtek/rtw88/mac80211.c b/drivers/net/wireless/realtek/rtw88/mac80211.c
index 776a9a9884b5..3b92ac611d3f 100644
--- a/drivers/net/wireless/realtek/rtw88/mac80211.c
+++ b/drivers/net/wireless/realtek/rtw88/mac80211.c
@@ -737,7 +737,7 @@ 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,
@@ -746,7 +746,9 @@ static int rtw_ops_set_bitrate_mask(struct ieee80211_hw *hw,
{
struct rtw_dev *rtwdev = hw->priv;

+ mutex_lock(&rtwdev->mutex);
rtw_ra_mask_info_update(rtwdev, vif, mask);
+ mutex_unlock(&rtwdev->mutex);

return 0;
}
--
2.39.0