[PATCH 5.10.y 3/3] wifi: mt76: mt7615: avoid waiting for mac work under the mt76 mutex

[Sasha Levin <sashal@kernel.org>]

From: Runyu Xiao <runyu.xiao@seu.edu.cn>

[ Upstream commit bda8324270b1ac91bfba1df8928e0570e29759e8 ]

mt7615_suspend() acquired the mt76 mutex and then called
cancel_delayed_work_sync() on mac_work.  mt7615_mac_work() acquires the
same mutex via mt7615_mutex_acquire() at the top of the worker, so if
mac_work is already running and blocked on the mutex, the suspend path
deadlocks waiting for the work it holds the mutex against.

Flush scan_work and mac_work before taking the mutex, matching the
suspend paths in mt7921 and mt7925.  scan_work only takes the mt76
spinlock, but moving it keeps the sequence consistent.  This also keeps
mac_work from running over an already suspended HIF, which the previous
split (async cancel under the lock, sync cancel after release) would
have allowed.

Fixes: c6bf20109a3f ("mt76: mt7615: add WoW support")
Cc: stable@vger.kernel.org
Signed-off-by: Runyu Xiao <runyu.xiao@seu.edu.cn>
Link: https://patch.msgid.link/20260612041331.2596331-1-runyu.xiao@seu.edu.cn
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/wireless/mediatek/mt76/mt7615/main.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/main.c b/drivers/net/wireless/mediatek/mt76/mt7615/main.c
index c67ac255059d9..7c05fc6e8c1b5 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7615/main.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7615/main.c
@@ -1143,11 +1143,12 @@ static int mt7615_suspend(struct ieee80211_hw *hw,
 	cancel_delayed_work_sync(&dev->pm.ps_work);
 	mt7615_free_pending_tx_skbs(dev, NULL);
 
+	cancel_delayed_work_sync(&phy->scan_work);
+	cancel_delayed_work_sync(&phy->mt76->mac_work);
+
 	mt7615_mutex_acquire(dev);
 
 	clear_bit(MT76_STATE_RUNNING, &phy->mt76->state);
-	cancel_delayed_work_sync(&phy->scan_work);
-	cancel_delayed_work_sync(&phy->mt76->mac_work);
 
 	mt76_set(dev, MT_WF_RFCR(ext_phy), MT_WF_RFCR_DROP_OTHER_BEACON);
 
-- 
2.53.0