Comment 4 for bug 2045387

The correct way to backport this driver should be
1. check the driver SHA1 on the mainline kernel
   $ git log --oneline drivers/net/can/usb/f81604.c
   88da17436973 can: usb: f81604: add Fintek F81604 support
2. add the mainline kernel git tree to focal kernel tree
   $ git remote add linus git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
3. fetch the mainline kernel source
   $ git fetch linus
4. cherry pick the commit we want
   $ git cherry-pick -xse 88da17436973
5. fix the conflict file, Makefile, and then add it
   $ (after solved the Makefile conflict) git add -u
6. modify the commit message, add BugLink and replace "cherry picked" to "backported"
   $ git cherry-pick --continue
7. then you can generate this patch for review