mt76: mt76x02: remove bogus mutex usage

mac80211 .start(), .stop() callbacks are never called concurrently with
other callbacks. The only concurencly is with mt76 works which we cancel
on stop() and schedule on start().

This fixes possible deadlock on cancel_delayed_work_sync(&dev->mac_work)
as mac_work also take mutex.

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

diff --git a/drivers/net/wireless/mediatek/mt76/mt76x0/pci.c b/drivers/net/wireless/mediatek/mt76/mt76x0/pci.c
index f106dbfa665fcc16fc7d8eb6df70779f3eb8fd0a..0eeccc3b529d20a3294387398a0587fdf72fffd6 100644 (file)
--- a/drivers/net/wireless/mediatek/mt76/mt76x0/pci.c
+++ b/drivers/net/wireless/mediatek/mt76/mt76x0/pci.c
@@ -25,8 +25,6 @@ static int mt76x0e_start(struct ieee80211_hw *hw)
 {
        struct mt76x02_dev *dev = hw->priv;
 
-       mutex_lock(&dev->mt76.mutex);
-
        mt76x02_mac_start(dev);
        mt76x0_phy_calibrate(dev, true);
        ieee80211_queue_delayed_work(dev->mt76.hw, &dev->mt76.mac_work,
@@ -35,8 +33,6 @@ static int mt76x0e_start(struct ieee80211_hw *hw)
                                     MT_CALIBRATE_INTERVAL);
        set_bit(MT76_STATE_RUNNING, &dev->mt76.state);
 
-       mutex_unlock(&dev->mt76.mutex);
-
        return 0;
 }
 
@@ -62,10 +58,8 @@ static void mt76x0e_stop(struct ieee80211_hw *hw)
 {
        struct mt76x02_dev *dev = hw->priv;
 
-       mutex_lock(&dev->mt76.mutex);
        clear_bit(MT76_STATE_RUNNING, &dev->mt76.state);
        mt76x0e_stop_hw(dev);
-       mutex_unlock(&dev->mt76.mutex);
 }
 
 static void

diff --git a/drivers/net/wireless/mediatek/mt76/mt76x0/usb.c b/drivers/net/wireless/mediatek/mt76/mt76x0/usb.c
index 406ebfa74195d5aeea4934f607d791513cd86889..7c38ec4418db23c35cba39e9e5ad55b8118eb22b 100644 (file)
--- a/drivers/net/wireless/mediatek/mt76/mt76x0/usb.c
+++ b/drivers/net/wireless/mediatek/mt76/mt76x0/usb.c
@@ -81,8 +81,10 @@ static void mt76x0u_cleanup(struct mt76x02_dev *dev)
        mt76u_queues_deinit(&dev->mt76);
 }
 
-static void mt76x0u_mac_stop(struct mt76x02_dev *dev)
+static void mt76x0u_stop(struct ieee80211_hw *hw)
 {
+       struct mt76x02_dev *dev = hw->priv;
+
        clear_bit(MT76_STATE_RUNNING, &dev->mt76.state);
        cancel_delayed_work_sync(&dev->cal_work);
        cancel_delayed_work_sync(&dev->mt76.mac_work);
@@ -106,11 +108,9 @@ static int mt76x0u_start(struct ieee80211_hw *hw)
        struct mt76x02_dev *dev = hw->priv;
        int ret;
 
-       mutex_lock(&dev->mt76.mutex);
-
        ret = mt76x0_mac_start(dev);
        if (ret)
-               goto out;
+               return ret;
 
        mt76x0_phy_calibrate(dev, true);
        ieee80211_queue_delayed_work(dev->mt76.hw, &dev->mt76.mac_work,
@@ -118,19 +118,7 @@ static int mt76x0u_start(struct ieee80211_hw *hw)
        ieee80211_queue_delayed_work(dev->mt76.hw, &dev->cal_work,
                                     MT_CALIBRATE_INTERVAL);
        set_bit(MT76_STATE_RUNNING, &dev->mt76.state);
-
-out:
-       mutex_unlock(&dev->mt76.mutex);
-       return ret;
-}
-
-static void mt76x0u_stop(struct ieee80211_hw *hw)
-{
-       struct mt76x02_dev *dev = hw->priv;
-
-       mutex_lock(&dev->mt76.mutex);
-       mt76x0u_mac_stop(dev);
-       mutex_unlock(&dev->mt76.mutex);
+       return 0;
 }
 
 static const struct ieee80211_ops mt76x0u_ops = {

diff --git a/drivers/net/wireless/mediatek/mt76/mt76x2/pci_main.c b/drivers/net/wireless/mediatek/mt76/mt76x2/pci_main.c
index 77f63cb14f35e3e5cc0414aeb6a72436bff44133..ab716957b8ba7856be93a88075e64275b3980fc8 100644 (file)
--- a/drivers/net/wireless/mediatek/mt76/mt76x2/pci_main.c
+++ b/drivers/net/wireless/mediatek/mt76/mt76x2/pci_main.c
@@ -22,15 +22,13 @@ mt76x2_start(struct ieee80211_hw *hw)
        struct mt76x02_dev *dev = hw->priv;
        int ret;
 
-       mutex_lock(&dev->mt76.mutex);
-
        ret = mt76x2_mac_start(dev);
        if (ret)
-               goto out;
+               return ret;
 
        ret = mt76x2_phy_start(dev);
        if (ret)
-               goto out;
+               return ret;
 
        ieee80211_queue_delayed_work(mt76_hw(dev), &dev->mt76.mac_work,
                                     MT_MAC_WORK_INTERVAL);
@@ -38,10 +36,7 @@ mt76x2_start(struct ieee80211_hw *hw)
                                     MT_WATCHDOG_TIME);
 
        set_bit(MT76_STATE_RUNNING, &dev->mt76.state);
-
-out:
-       mutex_unlock(&dev->mt76.mutex);
-       return ret;
+       return 0;
 }
 
 static void
@@ -49,10 +44,8 @@ mt76x2_stop(struct ieee80211_hw *hw)
 {
        struct mt76x02_dev *dev = hw->priv;
 
-       mutex_lock(&dev->mt76.mutex);
        clear_bit(MT76_STATE_RUNNING, &dev->mt76.state);
        mt76x2_stop_hardware(dev);
-       mutex_unlock(&dev->mt76.mutex);
 }
 
 static int

diff --git a/drivers/net/wireless/mediatek/mt76/mt76x2/usb_main.c b/drivers/net/wireless/mediatek/mt76/mt76x2/usb_main.c
index 305977a874a42f975b87fb438b00d83bc55c8539..97bcf6494ec1754b1748e9ede4740c6bfc7f78a5 100644 (file)
--- a/drivers/net/wireless/mediatek/mt76/mt76x2/usb_main.c
+++ b/drivers/net/wireless/mediatek/mt76/mt76x2/usb_main.c
@@ -21,30 +21,24 @@ static int mt76x2u_start(struct ieee80211_hw *hw)
        struct mt76x02_dev *dev = hw->priv;
        int ret;
 
-       mutex_lock(&dev->mt76.mutex);
-
        ret = mt76x2u_mac_start(dev);
        if (ret)
-               goto out;
+               return ret;
 
        ieee80211_queue_delayed_work(mt76_hw(dev), &dev->mt76.mac_work,
                                     MT_MAC_WORK_INTERVAL);
        set_bit(MT76_STATE_RUNNING, &dev->mt76.state);
 
-out:
-       mutex_unlock(&dev->mt76.mutex);
-       return ret;
+       return 0;
 }
 
 static void mt76x2u_stop(struct ieee80211_hw *hw)
 {
        struct mt76x02_dev *dev = hw->priv;
 
-       mutex_lock(&dev->mt76.mutex);
        clear_bit(MT76_STATE_RUNNING, &dev->mt76.state);
        mt76u_stop_tx(&dev->mt76);
        mt76x2u_stop_hw(dev);
-       mutex_unlock(&dev->mt76.mutex);
 }
 
 static int