> > I see, we shutdown the socket immediately since the socket API itself > > don't seem to have a concept of disconnect syscall not sure if other > > values could be passed to shutdown second parameter to indicate we > > want to actually wait it to be disconnected. I don't think the second parameter matters, I tried every possible valid values and intr_watch_cb is still called without waiting for the response. > > in a blocking synchronous system call world we have SO_LINGER for that. In the world of asynchronous IO handling (what we do), we need to check what is the right way of handling this. > I spot this piece of code [1] which utilizes getsockopt to query socket connection information from the kernel space to the user space. We can use a similar method to query whether (sk->sk_state == BT_CLOSED), which is only true when we get the response. What do you think? [1] https://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth-next.git/tree/net/bluetooth/l2cap_sock.c#n476
