[PATCH 5.0 v2] mt76x0u: fix suspend/resume

[Stanislaw Gruszka <sgruszka@redhat.com>]

We need to reset MCU and do other initializations on resume otherwise
MT7610U device will fail to initialize, what cause system hung due to
USB requests timeouts.

Patch fixes 4.19 -> 4.20 regression.

Cc: stable@vger.kernel.org # 4.20+
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
---
v2: minor coding style changes

 drivers/net/wireless/mediatek/mt76/mt76x0/usb.c | 46 ++++++++++++++++---------
 1 file changed, 29 insertions(+), 17 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt76x0/usb.c b/drivers/net/wireless/mediatek/mt76/mt76x0/usb.c
index 0e6b43bb4678..a5ea3ba495a4 100644
--- a/drivers/net/wireless/mediatek/mt76/mt76x0/usb.c
+++ b/drivers/net/wireless/mediatek/mt76/mt76x0/usb.c
@@ -158,39 +158,49 @@ static const struct ieee80211_ops mt76x0u_ops = {
 	.get_txpower = mt76x02_get_txpower,
 };
 
-static int mt76x0u_register_device(struct mt76x02_dev *dev)
+static int mt76x0u_init_hardware(struct mt76x02_dev *dev)
 {
-	struct ieee80211_hw *hw = dev->mt76.hw;
 	int err;
 
-	err = mt76u_alloc_queues(&dev->mt76);
-	if (err < 0)
-		goto out_err;
-
-	err = mt76u_mcu_init_rx(&dev->mt76);
-	if (err < 0)
-		goto out_err;
-
 	mt76x0_chip_onoff(dev, true, true);
-	if (!mt76x02_wait_for_mac(&dev->mt76)) {
-		err = -ETIMEDOUT;
-		goto out_err;
-	}
+
+	if (!mt76x02_wait_for_mac(&dev->mt76))
+		return -ETIMEDOUT;
 
 	err = mt76x0u_mcu_init(dev);
 	if (err < 0)
-		goto out_err;
+		return err;
 
 	mt76x0_init_usb_dma(dev);
 	err = mt76x0_init_hardware(dev);
 	if (err < 0)
-		goto out_err;
+		return err;
 
 	mt76_rmw(dev, MT_US_CYC_CFG, MT_US_CYC_CNT, 0x1e);
 	mt76_wr(dev, MT_TXOP_CTRL_CFG,
 		FIELD_PREP(MT_TXOP_TRUN_EN, 0x3f) |
 		FIELD_PREP(MT_TXOP_EXT_CCA_DLY, 0x58));
 
+	return 0;
+}
+
+static int mt76x0u_register_device(struct mt76x02_dev *dev)
+{
+	struct ieee80211_hw *hw = dev->mt76.hw;
+	int err;
+
+	err = mt76u_alloc_queues(&dev->mt76);
+	if (err < 0)
+		goto out_err;
+
+	err = mt76u_mcu_init_rx(&dev->mt76);
+	if (err < 0)
+		goto out_err;
+
+	err = mt76x0u_init_hardware(dev);
+	if (err < 0)
+		goto out_err;
+
 	err = mt76x0_register_device(dev);
 	if (err < 0)
 		goto out_err;
@@ -301,6 +311,8 @@ static int __maybe_unused mt76x0_suspend(struct usb_interface *usb_intf,
 
 	mt76u_stop_queues(&dev->mt76);
 	mt76x0u_mac_stop(dev);
+	clear_bit(MT76_STATE_MCU_RUNNING, &dev->mt76.state);
+	mt76x0_chip_onoff(dev, false, false);
 	usb_kill_urb(usb->mcu.res.urb);
 
 	return 0;
@@ -328,7 +340,7 @@ static int __maybe_unused mt76x0_resume(struct usb_interface *usb_intf)
 	tasklet_enable(&usb->rx_tasklet);
 	tasklet_enable(&usb->tx_tasklet);
 
-	ret = mt76x0_init_hardware(dev);
+	ret = mt76x0u_init_hardware(dev);
 	if (ret)
 		goto err;
 
-- 
2.7.5