Bluetooth: btusb: mediatek: reset the controller before downloading the fw

[ Upstream commit ccfc894 ]

Reset the controller before downloading the firmware to improve its
reliability. This includes situations like cold or warm reboots, ensuring
the controller is in its initial state before starting the firmware
download.

Co-developed-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Co-developed-by: Chris Lu <chris.lu@mediatek.com>
Signed-off-by: Chris Lu <chris.lu@mediatek.com>
Signed-off-by: Hao Qin <hao.qin@mediatek.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Stable-dep-of: 5c5e8c5 ("Bluetooth: btmtk: move btusb_mtk_[setup, shutdown] to btmtk.c")
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: Hao Qin

drivers/bluetooth/btusb.c

@@ -2940,16 +2940,26 @@ static int btusb_mtk_setup(struct hci_dev *hdev)
 	case 0x7922:
 	case 0x7961:
 	case 0x7925:
+		/* Reset the device to ensure it's in the initial state before
+		 * downloading the firmware to ensure.
+		 */
+
+		if (!test_bit(BTUSB_FIRMWARE_LOADED, &data->flags))
+			btusb_mtk_subsys_reset(hdev, dev_id);
+
 		btmtk_fw_get_filename(fw_bin_name, sizeof(fw_bin_name), dev_id,
 				      fw_version, 0);
 
 		err = btmtk_setup_firmware_79xx(hdev, fw_bin_name,
 						btmtk_usb_hci_wmt_sync);
 		if (err < 0) {
 			bt_dev_err(hdev, "Failed to set up firmware (%d)", err);
+			clear_bit(BTUSB_FIRMWARE_LOADED, &data->flags);
 			return err;
 		}
 
+		set_bit(BTUSB_FIRMWARE_LOADED, &data->flags);
+
 		/* It's Device EndPoint Reset Option Register */
 		btusb_mtk_uhw_reg_write(data, MTK_EP_RST_OPT, MTK_EP_RST_IN_OUT_OPT);