mt76: mt7615: fix possible deadlock in mt7615_stop

make mac_work per phy instead of per device and fix a possible deadlock
in mt7615_stop since mt7615_mac_work runs holding mt76 mutex

Fixes: fdd2e570764c2 ("mt76: mt7615: add dual-phy support for mac80211 ops")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/init.c b/drivers/net/wireless/mediatek/mt76/mt7615/init.c
index cb626a2..f06de74 100644 (file)
--- a/drivers/net/wireless/mediatek/mt76/mt7615/init.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7615/init.c
@@ -429,6 +429,7 @@ int mt7615_register_ext_phy(struct mt7615_dev *dev)
        if (phy)
                return 0;
 
+       INIT_DELAYED_WORK(&phy->mac_work, mt7615_mac_work);
        INIT_DELAYED_WORK(&phy->scan_work, mt7615_scan_work);
        skb_queue_head_init(&phy->scan_event_list);
 
@@ -487,7 +488,7 @@ void mt7615_init_device(struct mt7615_dev *dev)
        dev->phy.dev = dev;
        dev->phy.mt76 = &dev->mt76.phy;
        dev->mt76.phy.priv = &dev->phy;
-       INIT_DELAYED_WORK(&dev->mt76.mac_work, mt7615_mac_work);
+       INIT_DELAYED_WORK(&dev->phy.mac_work, mt7615_mac_work);
        INIT_DELAYED_WORK(&dev->phy.scan_work, mt7615_scan_work);
        skb_queue_head_init(&dev->phy.scan_event_list);
        INIT_LIST_HEAD(&dev->sta_poll_list);

diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/mac.c b/drivers/net/wireless/mediatek/mt76/mt7615/mac.c
index c38bc39..5614cd6 100644 (file)
--- a/drivers/net/wireless/mediatek/mt76/mt7615/mac.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7615/mac.c
@@ -1815,31 +1815,27 @@ mt7615_mac_update_mib_stats(struct mt7615_phy *phy)
 
 void mt7615_mac_work(struct work_struct *work)
 {
-       struct mt7615_dev *dev;
-       struct mt7615_phy *ext_phy;
+       struct mt7615_phy *phy;
+       struct mt76_dev *mdev;
 
-       dev = (struct mt7615_dev *)container_of(work, struct mt76_dev,
+       phy = (struct mt7615_phy *)container_of(work, struct mt7615_phy,
                                                mac_work.work);
+       mdev = &phy->dev->mt76;
 
-       mutex_lock(&dev->mt76.mutex);
-       mt76_update_survey(&dev->mt76);
-       if (++dev->mac_work_count == 5) {
-               ext_phy = mt7615_ext_phy(dev);
-
-               mt7615_mac_update_mib_stats(&dev->phy);
-               mt7615_mac_scs_check(&dev->phy);
-               if (ext_phy) {
-                       mt7615_mac_update_mib_stats(ext_phy);
-                       mt7615_mac_scs_check(ext_phy);
-               }
+       mutex_lock(&mdev->mutex);
 
-               dev->mac_work_count = 0;
+       mt76_update_survey(mdev);
+       if (++phy->mac_work_count == 5) {
+               phy->mac_work_count = 0;
+
+               mt7615_mac_update_mib_stats(phy);
+               mt7615_mac_scs_check(phy);
        }
 
-       mutex_unlock(&dev->mt76.mutex);
+       mutex_unlock(&mdev->mutex);
 
-       mt76_tx_status_check(&dev->mt76, NULL, false);
-       ieee80211_queue_delayed_work(mt76_hw(dev), &dev->mt76.mac_work,
+       mt76_tx_status_check(mdev, NULL, false);
+       ieee80211_queue_delayed_work(phy->mt76->hw, &phy->mac_work,
                                     MT7615_WATCHDOG_TIME);
 }
 
@@ -1902,26 +1898,32 @@ mt7615_dma_reset(struct mt7615_dev *dev)
 
 void mt7615_mac_reset_work(struct work_struct *work)
 {
+       struct mt7615_phy *phy2;
+       struct mt76_phy *ext_phy;
        struct mt7615_dev *dev;
 
        dev = container_of(work, struct mt7615_dev, reset_work);
+       ext_phy = dev->mt76.phy2;
+       phy2 = ext_phy ? ext_phy->priv : NULL;
 
        if (!(READ_ONCE(dev->reset_state) & MT_MCU_CMD_STOP_PDMA))
                return;
 
        ieee80211_stop_queues(mt76_hw(dev));
-       if (dev->mt76.phy2)
-               ieee80211_stop_queues(dev->mt76.phy2->hw);
+       if (ext_phy)
+               ieee80211_stop_queues(ext_phy->hw);
 
        set_bit(MT76_RESET, &dev->mphy.state);
        set_bit(MT76_MCU_RESET, &dev->mphy.state);
        wake_up(&dev->mt76.mcu.wait);
-       cancel_delayed_work_sync(&dev->mt76.mac_work);
+       cancel_delayed_work_sync(&dev->phy.mac_work);
+       if (phy2)
+               cancel_delayed_work_sync(&phy2->mac_work);
 
        /* lock/unlock all queues to ensure that no tx is pending */
        mt76_txq_schedule_all(&dev->mphy);
-       if (dev->mt76.phy2)
-               mt76_txq_schedule_all(dev->mt76.phy2);
+       if (ext_phy)
+               mt76_txq_schedule_all(ext_phy);
 
        tasklet_disable(&dev->mt76.tx_tasklet);
        napi_disable(&dev->mt76.napi[0]);
@@ -1955,8 +1957,8 @@ void mt7615_mac_reset_work(struct work_struct *work)
        napi_schedule(&dev->mt76.napi[1]);
 
        ieee80211_wake_queues(mt76_hw(dev));
-       if (dev->mt76.phy2)
-               ieee80211_wake_queues(dev->mt76.phy2->hw);
+       if (ext_phy)
+               ieee80211_wake_queues(ext_phy->hw);
 
        mt76_wr(dev, MT_MCU_INT_EVENT, MT_MCU_INT_EVENT_RESET_DONE);
        mt7615_wait_reset_state(dev, MT_MCU_CMD_NORMAL_STATE);
@@ -1965,8 +1967,12 @@ void mt7615_mac_reset_work(struct work_struct *work)
 
        mt7615_update_beacons(dev);
 
-       ieee80211_queue_delayed_work(mt76_hw(dev), &dev->mt76.mac_work,
+       ieee80211_queue_delayed_work(mt76_hw(dev), &dev->phy.mac_work,
                                     MT7615_WATCHDOG_TIME);
+       if (phy2)
+               ieee80211_queue_delayed_work(ext_phy->hw, &phy2->mac_work,
+                                            MT7615_WATCHDOG_TIME);
+
 }
 
 static void mt7615_dfs_stop_radar_detector(struct mt7615_phy *phy)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/main.c b/drivers/net/wireless/mediatek/mt76/mt7615/main.c
index b346080..33f67c7 100644 (file)
--- a/drivers/net/wireless/mediatek/mt76/mt7615/main.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7615/main.c
@@ -55,15 +55,12 @@ static int mt7615_start(struct ieee80211_hw *hw)
 
        set_bit(MT76_STATE_RUNNING, &phy->mt76->state);
 
-       if (running)
-               goto out;
-
-       mt7615_mac_reset_counters(dev);
-
-       ieee80211_queue_delayed_work(mt76_hw(dev), &dev->mt76.mac_work,
+       ieee80211_queue_delayed_work(hw, &phy->mac_work,
                                     MT7615_WATCHDOG_TIME);
 
-out:
+       if (!running)
+               mt7615_mac_reset_counters(dev);
+
        mutex_unlock(&dev->mt76.mutex);
 
        return 0;
@@ -74,6 +71,8 @@ static void mt7615_stop(struct ieee80211_hw *hw)
        struct mt7615_dev *dev = mt7615_hw_dev(hw);
        struct mt7615_phy *phy = mt7615_hw_phy(hw);
 
+       cancel_delayed_work_sync(&phy->mac_work);
+
        mutex_lock(&dev->mt76.mutex);
 
        clear_bit(MT76_STATE_RUNNING, &phy->mt76->state);
@@ -85,8 +84,6 @@ static void mt7615_stop(struct ieee80211_hw *hw)
        }
 
        if (!mt7615_dev_running(dev)) {
-               cancel_delayed_work_sync(&dev->mt76.mac_work);
-
                mt7615_mcu_set_pm(dev, 0, 1);
                mt7615_mcu_set_mac_enable(dev, 0, false);
        }
@@ -245,7 +242,7 @@ static int mt7615_set_channel(struct mt7615_phy *phy)
        bool ext_phy = phy != &dev->phy;
        int ret;
 
-       cancel_delayed_work_sync(&dev->mt76.mac_work);
+       cancel_delayed_work_sync(&phy->mac_work);
 
        mutex_lock(&dev->mt76.mutex);
        set_bit(MT76_RESET, &phy->mt76->state);
@@ -276,7 +273,7 @@ out:
        mutex_unlock(&dev->mt76.mutex);
 
        mt76_txq_schedule_all(phy->mt76);
-       ieee80211_queue_delayed_work(mt76_hw(dev), &dev->mt76.mac_work,
+       ieee80211_queue_delayed_work(phy->mt76->hw, &phy->mac_work,
                                     MT7615_WATCHDOG_TIME);
        return ret;
 }

diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/mt7615.h b/drivers/net/wireless/mediatek/mt76/mt7615/mt7615.h
index 10a98d3..57c9c1e 100644 (file)
--- a/drivers/net/wireless/mediatek/mt76/mt7615/mt7615.h
+++ b/drivers/net/wireless/mediatek/mt76/mt7615/mt7615.h
@@ -192,6 +192,9 @@ struct mt7615_phy {
 
        struct mib_stats mib;
 
+       struct delayed_work mac_work;
+       u8 mac_work_count;
+
        struct sk_buff_head scan_event_list;
        struct delayed_work scan_work;
 };
@@ -259,7 +262,6 @@ struct mt7615_dev {
        } radar_pattern;
        u32 hw_pattern;
 
-       u8 mac_work_count;
        bool fw_debug;
        bool flash_eeprom;