[PATCH 2/3] wifi: mt76: mt7925: fix missing mutex protection in reset and ROC abort

[Zac Bowling]

From: Zac Bowling <zac at zacbowling.com>

During firmware recovery and ROC (Remain On Channel) abort operations,
the driver iterates over active interfaces and calls MCU functions that
require the device mutex to be held, but the mutex was not acquired.

This causes system-wide hangs where network commands hang indefinitely,
processes get stuck in uninterruptible sleep (D state), and the system
becomes completely unresponsive requiring force reboot.

Add mutex protection around interface iteration in:
- mt7925_mac_reset_work(): Called during firmware recovery after MCU
  timeouts to reconnect all interfaces
- mt7925_roc_abort_sync(): Called during suspend/resume and when aborting
  Remain On Channel operations

This matches the pattern used elsewhere in the driver where interface
iteration callbacks invoke MCU functions.

Reported-by: Zac Bowling <zac at zacbowling.com>
Tested-by: Zac Bowling <zac at zacbowling.com>
Signed-off-by: Zac Bowling <zac at zacbowling.com>
---
 drivers/net/wireless/mediatek/mt76/mt7925/mac.c | 2 ++
 drivers/net/wireless/mediatek/mt76/mt7925/pci.c | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7925/mac.c b/drivers/net/wireless/mediatek/mt76/mt7925/mac.c
index 184efe8afa10..06420ac6ed55 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7925/mac.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7925/mac.c
@@ -1331,9 +1331,11 @@ void mt7925_mac_reset_work(struct work_struct *work)
 	dev->hw_full_reset = false;
 	pm->suspended = false;
 	ieee80211_wake_queues(hw);
+	mt792x_mutex_acquire(dev);
 	ieee80211_iterate_active_interfaces(hw,
 					    IEEE80211_IFACE_ITER_RESUME_ALL,
 					    mt7925_vif_connect_iter, NULL);
+	mt792x_mutex_release(dev);
 	mt76_connac_power_save_sched(&dev->mt76.phy, pm);
 
 	mt7925_regd_change(&dev->phy, "00");
diff --git a/drivers/net/wireless/mediatek/mt76/mt7925/pci.c b/drivers/net/wireless/mediatek/mt76/mt7925/pci.c
index c4161754c01d..e9d62c6aee91 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7925/pci.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7925/pci.c
@@ -455,7 +455,9 @@ static int mt7925_pci_suspend(struct device *device)
 	cancel_delayed_work_sync(&pm->ps_work);
 	cancel_work_sync(&pm->wake_work);
 
+	mt792x_mutex_acquire(dev);
 	mt7925_roc_abort_sync(dev);
+	mt792x_mutex_release(dev);
 
 	err = mt792x_mcu_drv_pmctrl(dev);
 	if (err < 0)
-- 
2.51.0