deviceLookup :: DeviceManager -> DevicePath -> Sys (Maybe DeviceTree)
deviceLookup dm path = deviceTreeLookup path <$> readTVarIO (dmDevices dm)
deviceLookup :: DeviceManager -> DevicePath -> Sys (Maybe DeviceTree)
deviceLookup dm path = deviceTreeLookup path <$> readTVarIO (dmDevices dm)
deviceLookup dm path = deviceTreeLookup path <$> readTVarIO (dmDevices dm)