[PATCH 5.19 246/717] wifi: mt76: mt7921: add mt7921_mutex_acquire at mt7921_[start, stop]_ap

Greg Kroah-Hartman
2022-10-22T07:52:56Z

From: Sean Wang <sean.wang@mediatek.com>

[ Upstream commit 52b44015f031f629f1ce1d73415a2017593c7ade ]

Add mt7921_mutex_acquire at mt7921_[start, stop]_ap to fix the race
with the context holding dev->muxtex and the driver might access the
device in low power state.

Fixes: 9d958b60ebc2 ("mt76: mt7921: fix command timeout in AP stop period")
Tested-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Acked-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
.../net/wireless/mediatek/mt76/mt7921/main.c | 21 ++++++++++++++-----
1 file changed, 16 insertions(+), 5 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/main.c b/drivers/net/wireless/mediatek/mt76/mt7921/main.c
index d3f310877248..22c9793e4a40 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7921/main.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7921/main.c
@@ -1499,17 +1499,23 @@ mt7921_start_ap(struct ieee80211_hw *hw, struct ieee80211_vif *vif)
struct mt7921_dev *dev = mt7921_hw_dev(hw);
int err;

+ mt7921_mutex_acquire(dev);
+
err = mt76_connac_mcu_uni_add_bss(phy->mt76, vif, &mvif->sta.wcid,
true);
if (err)
- return err;
+ goto out;

err = mt7921_mcu_set_bss_pm(dev, vif, true);
if (err)
- return err;
+ goto out;
+
+ err = mt7921_mcu_sta_update(dev, NULL, vif, true,
+ MT76_STA_INFO_STATE_NONE);
+out:
+ mt7921_mutex_release(dev);

- return mt7921_mcu_sta_update(dev, NULL, vif, true,
- MT76_STA_INFO_STATE_NONE);
+ return err;
}

static void
@@ -1520,11 +1526,16 @@ mt7921_stop_ap(struct ieee80211_hw *hw, struct ieee80211_vif *vif)
struct mt7921_dev *dev = mt7921_hw_dev(hw);
int err;

+ mt7921_mutex_acquire(dev);
+
err = mt7921_mcu_set_bss_pm(dev, vif, false);
if (err)
- return;
+ goto out;

mt76_connac_mcu_uni_add_bss(phy->mt76, vif, &mvif->sta.wcid, false);
+
+out:
+ mt7921_mutex_release(dev);
}

const struct ieee80211_ops mt7921_ops = {
--
2.35.1