Debian kernel 4.10(tag 4.10~rc6-1~exp1) also works fine. It appears the
problem is on Debian 4.9 kernel. I am not sure how to run git bisect on
Debian kernel. Tried anyway. It is pointing to
47811c66356d875e76a6ca637a9d384779a659bb is the first bad commit
commit 47811c66356d875e76a6ca637a9d384779a659bb
Author: Ben Hutchings<benh@xxxxxxxxxx>
Date: Mon Mar 8 01:17:32 2021 +0100
Prepare to release linux (4.9.258-1).
It does not appear to be the right commit. I am out of ideas now.
hanks