Given that the 'is_tx = 0' cannot be moved in the whole handler thanks to a achievable race in between the hold off in switching to STATE_RX_AACK_ON as well as a new interrupt, we introduce an intermediate 'was_tx' boolean only for this function. There is not any Fixes tag making https://erickorstt.bloggazzo.com/28151363/wordpress-plugins-for-dummies