Bluetooth: btmtk: Add reset mechanism if downloading firmware failed

Add a new flag 'BTMTK_FIRMWARE_DL_RETRY'.
If an error occurs during mt79xx firmware download process, this flag
will be set and cleared after a reset. If the flag is already set and
firmware still cannot be loaded successfully after a reset, no further
reset attempts will be made. In other words, if there is a problem during
firmware download, only one reset will be attempted.

Signed-off-by: Chris Lu <[e-mail]>
Signed-off-by: Luiz Augusto von Dentz <[e-mail]>

drivers/bluetooth/btmtk.c

···
 		err = btmtk_setup_firmware_79xx(hdev, fw_bin_name,
 						btmtk_usb_hci_wmt_sync);
 		if (err < 0) {
+			/* retry once if setup firmware error */
+			if (!test_and_set_bit(BTMTK_FIRMWARE_DL_RETRY, &btmtk_data->flags))
+				btmtk_reset_sync(hdev);
 			bt_dev_err(hdev, "Failed to set up firmware (%d)", err);
 			return err;
 		}
···
 
 		hci_set_msft_opcode(hdev, 0xFD30);
 		hci_set_aosp_capable(hdev);
+
+		/* Clear BTMTK_FIRMWARE_DL_RETRY if setup successfully */
+		test_and_clear_bit(BTMTK_FIRMWARE_DL_RETRY, &btmtk_data->flags);
 
 		/* Set up ISO interface after protocol enabled */
 		if (test_bit(BTMTK_ISOPKT_OVER_INTR, &btmtk_data->flags)) {

drivers/bluetooth/btmtk.h

···
 	BTMTK_HW_RESET_ACTIVE,
 	BTMTK_ISOPKT_OVER_INTR,
 	BTMTK_ISOPKT_RUNNING,
+	BTMTK_FIRMWARE_DL_RETRY,
 };
 
 typedef int (*btmtk_reset_sync_func_t)(struct hci_dev *, void *);