https://git.openwrt.org/?p=openwrt/openwrt.git;a=commit;h=ed087cba8a8e41f76f9487caa34eff926ea8a065
Based on this thread, there may be differences between the EA3500 and EA7300 - maybe post your Linksys model/version:
https://forum.openwrt.org/t/add-support-for-linksys-ea7300-v2/74563/18