Since the 'is_tx = 0' can't be moved in the entire handler thanks to a probable race between the delay in switching to STATE_RX_AACK_ON as well as a new interrupt, we introduce an intermediate 'was_tx' boolean only for this purpose. There is no Fixes tag making use of listed here, https://schemapro38271.thelateblog.com/29111421/helping-the-others-realize-the-advantages-of-wordpress-and-plugins