mt76: mt7921: fix a race between mt7921_mcu_drv_pmctrl and mt7921_mcu_fw_pmctrl

Introduce a mutex in order to avoid a race between mt7921_mcu_drv_pmctrl and
mt7921_mcu_fw_pmctrl routines since they are run two independent works

Fixes: 1d8efc741df8 ("mt76: mt7921: introduce Runtime PM support")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

diff --git a/drivers/net/wireless/mediatek/mt76/mt76_connac.h b/drivers/net/wireless/mediatek/mt76/mt76_connac.h
index b811f3c..2b31c97 100644 (file)
--- a/drivers/net/wireless/mediatek/mt76/mt76_connac.h
+++ b/drivers/net/wireless/mediatek/mt76/mt76_connac.h
@@ -54,6 +54,7 @@ struct mt76_connac_pm {
 
        struct work_struct wake_work;
        struct completion wake_cmpl;
+       struct mutex mutex;
 
        struct delayed_work ps_work;
        unsigned long last_activity;

diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/init.c b/drivers/net/wireless/mediatek/mt76/mt7921/init.c
index eab6e2d..0b8a5a7 100644 (file)
--- a/drivers/net/wireless/mediatek/mt76/mt7921/init.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7921/init.c
@@ -222,6 +222,7 @@ int mt7921_register_device(struct mt7921_dev *dev)
 
        INIT_DELAYED_WORK(&dev->pm.ps_work, mt7921_pm_power_save_work);
        INIT_WORK(&dev->pm.wake_work, mt7921_pm_wake_work);
+       mutex_init(&dev->pm.mutex);
        init_completion(&dev->pm.wake_cmpl);
        spin_lock_init(&dev->pm.txq_lock);
        set_bit(MT76_STATE_PM, &dev->mphy.state);

diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/mcu.c b/drivers/net/wireless/mediatek/mt76/mt7921/mcu.c
index 14ba856..ea00f6b 100644 (file)
--- a/drivers/net/wireless/mediatek/mt76/mt7921/mcu.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7921/mcu.c
@@ -1267,9 +1267,11 @@ int mt7921_mcu_set_bss_pm(struct mt7921_dev *dev, struct ieee80211_vif *vif,
 int mt7921_mcu_drv_pmctrl(struct mt7921_dev *dev)
 {
        struct mt76_phy *mphy = &dev->mt76.phy;
-       int i;
+       int i, err = 0;
 
-       if (!test_and_clear_bit(MT76_STATE_PM, &mphy->state))
+       mutex_lock(&dev->pm.mutex);
+
+       if (!test_bit(MT76_STATE_PM, &mphy->state))
                goto out;
 
        for (i = 0; i < MT7921_DRV_OWN_RETRY_COUNT; i++) {
@@ -1281,23 +1283,30 @@ int mt7921_mcu_drv_pmctrl(struct mt7921_dev *dev)
 
        if (i == MT7921_DRV_OWN_RETRY_COUNT) {
                dev_err(dev->mt76.dev, "driver own failed\n");
-               mt7921_reset(&dev->mt76);
-               return -EIO;
+               err = -EIO;
+               goto out;
        }
+       clear_bit(MT76_STATE_PM, &mphy->state);
 
 out:
        dev->pm.last_activity = jiffies;
+       mutex_unlock(&dev->pm.mutex);
 
-       return 0;
+       if (err)
+               mt7921_reset(&dev->mt76);
+
+       return err;
 }
 
 int mt7921_mcu_fw_pmctrl(struct mt7921_dev *dev)
 {
        struct mt76_phy *mphy = &dev->mt76.phy;
-       int i;
+       int i, err = 0;
+
+       mutex_lock(&dev->pm.mutex);
 
        if (test_and_set_bit(MT76_STATE_PM, &mphy->state))
-               return 0;
+               goto out;
 
        for (i = 0; i < MT7921_DRV_OWN_RETRY_COUNT; i++) {
                mt76_wr(dev, MT_CONN_ON_LPCTL, PCIE_LPCR_HOST_SET_OWN);
@@ -1308,11 +1317,16 @@ int mt7921_mcu_fw_pmctrl(struct mt7921_dev *dev)
 
        if (i == MT7921_DRV_OWN_RETRY_COUNT) {
                dev_err(dev->mt76.dev, "firmware own failed\n");
-               mt7921_reset(&dev->mt76);
-               return -EIO;
+               clear_bit(MT76_STATE_PM, &mphy->state);
+               err = -EIO;
        }
+out:
+       mutex_unlock(&dev->pm.mutex);
 
-       return 0;
+       if (err)
+               mt7921_reset(&dev->mt76);
+
+       return err;
 }
 
 void