[PATCH 1/1] Bluetooth: btusb: mediatek: add a recovery method for MT7922

[Hao Qin <hao.qin@mediatek.com>]

From: "hao.qin" <hao.qin@mediatek.com>

For MT7922, perform a reset before patch download to avoid
unexpected problems caused by inconsistency between upper layer
status and dongle status. Add USB reset retry to recover from
unexpected patch download failure.

Signed-off-by: hao.qin <hao.qin@mediatek.com>
---
 drivers/bluetooth/btusb.c | 66 +++++++++++++++++++++++++++------------
 1 file changed, 46 insertions(+), 20 deletions(-)

diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index 0926e4451802..778e1a0d9cae 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -2812,7 +2812,7 @@ static int btusb_mtk_hci_wmt_sync(struct hci_dev *hdev,
 	 * WMT command.
 	 */
 	err = wait_on_bit_timeout(&data->flags, BTUSB_TX_WAIT_VND_EVT,
-				  TASK_INTERRUPTIBLE, HCI_INIT_TIMEOUT);
+				  TASK_INTERRUPTIBLE, HCI_CMD_TIMEOUT);
 	if (err == -EINTR) {
 		bt_dev_err(hdev, "Execution of wmt command interrupted");
 		clear_bit(BTUSB_TX_WAIT_VND_EVT, &data->flags);
@@ -2994,28 +2994,22 @@ static u32 btusb_mtk_reset_done(struct hci_dev *hdev)
 	return val & MTK_BT_RST_DONE;
 }
 
-static int btusb_mtk_reset(struct hci_dev *hdev, void *rst_data)
+static int btusb_mtk_subsys_reset(struct hci_dev *hdev, u32 dev_id)
 {
 	struct btusb_data *data = hci_get_drvdata(hdev);
-	struct btmediatek_data *mediatek;
 	u32 val;
 	int err;
 
-	/* It's MediaTek specific bluetooth reset mechanism via USB */
-	if (test_and_set_bit(BTUSB_HW_RESET_ACTIVE, &data->flags)) {
-		bt_dev_err(hdev, "last reset failed? Not resetting again");
-		return -EBUSY;
-	}
-
-	err = usb_autopm_get_interface(data->intf);
-	if (err < 0)
-		return err;
-
-	btusb_stop_traffic(data);
-	usb_kill_anchored_urbs(&data->tx_anchor);
-	mediatek = hci_get_priv(hdev);
-
-	if (mediatek->dev_id == 0x7925) {
+	if (dev_id == 0x7922) {
+		btusb_mtk_uhw_reg_read(data, MTK_BT_SUBSYS_RST, &val);
+		val |= 0x00002020;
+		btusb_mtk_uhw_reg_write(data, MTK_BT_SUBSYS_RST, val);
+		btusb_mtk_uhw_reg_write(data, MTK_EP_RST_OPT, 0x00010001);
+		btusb_mtk_uhw_reg_read(data, MTK_BT_SUBSYS_RST, &val);
+		val |= (1 << 0);
+		btusb_mtk_uhw_reg_write(data, MTK_BT_SUBSYS_RST, val);
+		msleep(100);
+	} else if (dev_id == 0x7925) {
 		btusb_mtk_uhw_reg_read(data, MTK_BT_RESET_REG_CONNV3, &val);
 		val |= (1 << 5);
 		btusb_mtk_uhw_reg_write(data, MTK_BT_RESET_REG_CONNV3, val);
@@ -3053,14 +3047,41 @@ static int btusb_mtk_reset(struct hci_dev *hdev, void *rst_data)
 	err = readx_poll_timeout(btusb_mtk_reset_done, hdev, val,
 				 val & MTK_BT_RST_DONE, 20000, 1000000);
 	if (err < 0)
-		bt_dev_err(hdev, "Reset timeout");
+		bt_dev_err(hdev, "Subsys reset timeout");
+
+	if (dev_id == 0x7922)
+		btusb_mtk_uhw_reg_write(data, MTK_UDMA_INT_STA_BT, 0x000000FF);
 
 	btusb_mtk_id_get(data, 0x70010200, &val);
 	if (!val)
 		bt_dev_err(hdev, "Can't get device id, subsys reset fail.");
 
-	usb_queue_reset_device(data->intf);
+	return err;
+}
+
+static int btusb_mtk_reset(struct hci_dev *hdev, void *rst_data)
+{
+	struct btusb_data *data = hci_get_drvdata(hdev);
+	struct btmediatek_data *mediatek;
+	int err;
+
+	/* It's MediaTek specific bluetooth reset mechanism via USB */
+	if (test_and_set_bit(BTUSB_HW_RESET_ACTIVE, &data->flags)) {
+		bt_dev_err(hdev, "last reset failed? Not resetting again");
+		return -EBUSY;
+	}
+
+	err = usb_autopm_get_interface(data->intf);
+	if (err < 0)
+		return err;
+
+	btusb_stop_traffic(data);
+	usb_kill_anchored_urbs(&data->tx_anchor);
+	mediatek = hci_get_priv(hdev);
 
+	err = btusb_mtk_subsys_reset(hdev, mediatek->dev_id);
+
+	usb_queue_reset_device(data->intf);
 	clear_bit(BTUSB_HW_RESET_ACTIVE, &data->flags);
 
 	return err;
@@ -3119,6 +3140,8 @@ static int btusb_mtk_setup(struct hci_dev *hdev)
 		fwname = FIRMWARE_MT7668;
 		break;
 	case 0x7922:
+		btusb_mtk_subsys_reset(hdev, dev_id);
+		fallthrough;
 	case 0x7961:
 	case 0x7925:
 		if (dev_id == 0x7925)
@@ -3134,6 +3157,9 @@ static int btusb_mtk_setup(struct hci_dev *hdev)
 						btusb_mtk_hci_wmt_sync);
 		if (err < 0) {
 			bt_dev_err(hdev, "Failed to set up firmware (%d)", err);
+			btusb_stop_traffic(data);
+			usb_kill_anchored_urbs(&data->tx_anchor);
+			usb_queue_reset_device(data->intf);
 			return err;
 		}
 
-- 
2.18.0