+static int set_serial_info(struct acm *acm,
+ struct serial_struct __user *newinfo)
+{
+ struct serial_struct new_serial;
+ unsigned int closing_wait, close_delay;
+ int retval = 0;
+
+ if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
+ return -EFAULT;
+
+ close_delay = new_serial.close_delay * 10;
+ closing_wait = new_serial.closing_wait == ASYNC_CLOSING_WAIT_NONE ?
+ ASYNC_CLOSING_WAIT_NONE : new_serial.closing_wait * 10;
+
+ mutex_lock(&acm->port.mutex);
+
+ if (!capable(CAP_SYS_ADMIN)) {
+ if ((close_delay != acm->port.close_delay) ||
+ (closing_wait != acm->port.closing_wait))
+ retval = -EPERM;
+ else
+ retval = -EOPNOTSUPP;
+ } else {
+ acm->port.close_delay = close_delay;
+ acm->port.closing_wait = closing_wait;
+ }
+
+ mutex_unlock(&acm->port.mutex);
+ return retval;
+}
+