UPDATE: See also below part of this post: Installing on TP-Link TL-WR841N V13
at bottom of: https://github.com/lede-project/source/commit/24043a0d2e01b9843c0dc529205b3b0bc7ecbbf9
it says:
Flash instruction:
Until (if at all) TP-Link fixes described problem, the only way to flash
LEDE image in these devices is to use tftp recovery mode in U-Boot:
- Configure PC with static IP 192.168.0.66/24 and tftp server.
- Rename "lede-ramips-mt7628-tl-wr84...-squashfs-tftp-recovery.bin"
to "tp_recovery.bin" and place it in tftp server directory. - Connect PC with one of LAN ports, press the reset button, power up
the router and keep button pressed for around 6-7 seconds, until
device starts downloading the file. - Router will download file from server, write it to flash and reboot.
To access U-Boot CLI, keep pressed "4" key during boot.