Re: [PATCH 4/5] tty: n_gsm: initiate close of all DLCIs during mux shutdown

[Alan Cox <alan@lxorguk.ukuu.org.uk>]

On Fri,  3 Jun 2011 12:03:40 -0700
Russ Gorby <russ.gorby@intel.com> wrote:

> Although DLCI-0 is closed during ldisc close, we found the
> applications were better served when open DLCI shutdowns where
> initiated at that time as well.

They should all see a hangup on the gsm client tty anyway ?

> -	for (i = 0; i < NUM_DLCI; i++)
> +	for (i = NUM_DLCI-1; i >= 0; i--) {
> +		dlci = gsm->dlci[i];
> +		if (dlci) {
> +			if (i != 0)
> +				gsm_dlci_begin_close(dlci);
> +			else {
> +				dlci->dead = 1;
> +				gsm_dlci_begin_close(dlci);
> +				t = wait_event_timeout(gsm->event,
> +					   dlci->state == DLCI_CLOSED,
> +					   gsm->t2 * HZ / 100);
> +				if (!t) {
> +					pr_info("%s: timeout dlci0 close",
> +						__func__);
> +					gsm_dlci_close(dlci);
> +				}
> +			}
> +		}
> +	}
> +	for (i = NUM_DLCI-1; i >= 0; i--)

I'd like to understand better why it is needed and also why you don't
want for the others to close but just set it off ?