Francesco Lavra wrote:
> this patch adds support for reset_resume in cdc-acm. This function simply calls
> tty_hangup() if there was any user of the tty at suspend time, and then calls
> the normal resume function. Tested with a Samsung SGH-U900 device.
> Without reset_resume, every time the system is hibernated during a PPP
> connection, the device moves from ttyACMx to ttyACM(x+1), an it must be
> unplugged and replugged in order for its original node ttyACMx to re-appear.
> Instead, with reset_resume the device retains its node name across hibernation
> cycles.
Hi,
I'm playing with a back-port of this patch to v2.6.29 for a similar scenario
(suspend during an active PPP connection). I see that if we hit the
reset-resume, the tty_hangup() call results in the PPP connection getting dropped.
Do you know if it is possible to have the reset-resume without the
tty_hangup(), and without moving the device from ttyACMx to ttyACM(x+1)?
Thanks in advance,
Anand
> Signed-off-by: Francesco Lavra <francescolavra@xxxxxxxxxxxx>
>
> --- a/drivers/usb/class/cdc-acm.c 2009-12-07 16:22:20.000000000 +0100
> +++ b/drivers/usb/class/cdc-acm.c 2009-12-08 08:39:49.000000000 +0100
> @@ -1460,6 +1460,23 @@ err_out:
> return rv;
> }
>
> +static int acm_reset_resume(struct usb_interface *intf)
> +{
> + struct acm *acm = usb_get_intfdata(intf);
> + struct tty_struct *tty;
> +
> + mutex_lock(&acm->mutex);
> + if (acm->port.count) {
> + tty = tty_port_tty_get(&acm->port);
> + if (tty) {
> + tty_hangup(tty);
> + tty_kref_put(tty);
> + }
> + }
> + mutex_unlock(&acm->mutex);
> + return acm_resume(intf);
> +}
> +
> #endif /* CONFIG_PM */
> /*
> * USB driver structure.
> @@ -1546,6 +1563,7 @@ static struct usb_driver acm_driver = {
> #ifdef CONFIG_PM
> .suspend = acm_suspend,
> .resume = acm_resume,
> + .reset_resume = acm_reset_resume,
> #endif
> .id_table = acm_ids,
> #ifdef CONFIG_PM
>
>
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