This patch causes vcc_release_async to be applied to any open
vcc's when the modem is disconnected.  This signals a socket
shutdown, letting the socket user know that the game is up.
I wrote this patch because of reports that pppd would keep
connections open forever when the modem is disconnected.
This patch does not fix that problem, but it's a step in the
right direction.  It doesn't help because the pppoatm module
doesn't yet monitor state changes on the ATM socket, so simply
never realises that the ATM connection has gone down (meaning
it doesn't tell the ppp layer).  But at least there is a socket
state change now.  Unfortunately this patch may create problems
for those rare users like me who use routed IP or some other
non-ppp connection method that goes via the ATM ARP daemon: the
daemon is buggy, and with this patch will crash when the modem
is disconnected.  Users with a buggy atmarpd can simply restart
it after disconnecting the modem.

Signed-off-by: Duncan Sands <baldrick@free.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>