--- drivers/usb/class/cdc-acm.c

+++ drivers/usb/class/cdc-acm.c

@@ -297,6 +297,8 @@ static void acm_ctrl_irq(struct urb *urb

if (!ACM_READY(acm))

goto exit;

+ usb_mark_last_busy(acm->dev);

+

data = (unsigned char *)(dr + 1);

switch (dr->bNotificationType) {

case USB_CDC_NOTIFY_NETWORK_CONNECTION:

@@ -336,7 +338,6 @@ static void acm_ctrl_irq(struct urb *urb

break;

}

exit:

- usb_mark_last_busy(acm->dev);

retval = usb_submit_urb(urb, GFP_ATOMIC);

if (retval)

dev_err(&urb->dev->dev, "%s - usb_submit_urb failed with "

@@ -534,6 +535,8 @@ static void acm_softint(struct work_stru

if (!ACM_READY(acm))

return;

tty = tty_port_tty_get(&acm->port);

+ if (!tty)

+ return;

tty_wakeup(tty);

tty_kref_put(tty);

}

@@ -652,8 +655,10 @@ static void acm_port_down(struct acm *ac

usb_kill_urb(acm->ctrlurb);

for (i = 0; i < ACM_NW; i++)

usb_kill_urb(acm->wb[i].urb);

+ tasklet_disable(&acm->urb_task);

for (i = 0; i < nr; i++)

usb_kill_urb(acm->ru[i].urb);

+ tasklet_enable(&acm->urb_task);

acm->control->needs_remote_wakeup = 0;

usb_autopm_put_interface(acm->control);

}