easyteacher:

Device: Newifi D1
Software version: Linux Kernel 4.14.29

A similar problem has been reported [[https://www.spinics.net/lists/stable/msg227954.html|here]].
https://www.spinics.net/lists/stable/msg227954.html

I have tried to apply [[https://patchwork.ozlabs.org/patch/886324/|this patch]], and it works very well for there are no more annoying warning messages in dmesg and the system won't unexpectedly hang again. But it hasn't been accepted upstream.
https://patchwork.ozlabs.org/patch/886324/