static unsigned int n_tty_poll(struct tty_struct *tty, struct file *file,
poll_table *wait)
{
unsigned int mask = 0;
poll_wait(file, &tty->read_wait, wait);
poll_wait(file, &tty->write_wait, wait);
if (input_available_p(tty, TIME_CHAR(tty) ? 0 : MIN_CHAR(tty)))
mask |= POLLIN | POLLRDNORM;
if (tty->packet && tty->link->ctrl_status)
mask |= POLLPRI | POLLIN | POLLRDNORM;
if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
mask |= POLLHUP;
if (tty_hung_up_p(file))
mask |= POLLHUP;
if (!(mask & (POLLHUP | POLLIN | POLLRDNORM))) {
if (MIN_CHAR(tty) && !TIME_CHAR(tty))
tty->minimum_to_wake = MIN_CHAR(tty);
else
tty->minimum_to_wake = 1;
}
if (tty->ops->write && !tty_is_writelocked(tty) &&
tty_chars_in_buffer(tty) < WAKEUP_CHARS &&
tty_write_room(tty) > 0)
mask |= POLLOUT | POLLWRNORM;
return mask;
}
/**
* n_hdlc_tty_poll - TTY callback for poll system call
* @tty - pointer to tty instance data
* @filp - pointer to open file object for device
* @poll_table - wait queue for operations
*
* Determine which operations (read/write) will not block and return info
* to caller.
* Returns a bit mask containing info on which ops will not block.
*/
static unsigned int n_hdlc_tty_poll(struct tty_struct *tty, struct file *filp,
poll_table *wait)
{
struct n_hdlc *n_hdlc = tty2n_hdlc (tty);
unsigned int mask = 0;
if (debuglevel >= DEBUG_LEVEL_INFO)
printk("%s(%d)n_hdlc_tty_poll() called\n",__FILE__,__LINE__);
if (n_hdlc && n_hdlc->magic == HDLC_MAGIC && tty == n_hdlc->tty) {
/* queue current process into any wait queue that */
/* may awaken in the future (read and write) */
poll_wait(filp, &tty->read_wait, wait);
poll_wait(filp, &tty->write_wait, wait);
/* set bits for operations that won't block */
if (n_hdlc->rx_buf_list.head)
mask |= POLLIN | POLLRDNORM; /* readable */
if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
mask |= POLLHUP;
if (tty_hung_up_p(filp))
mask |= POLLHUP;
if (!tty_is_writelocked(tty) &&
n_hdlc->tx_free_buf_list.head)
mask |= POLLOUT | POLLWRNORM; /* writable */
}
return mask;
} /* end of n_hdlc_tty_poll() */
static unsigned int n_hdlc_tty_poll(struct tty_struct *tty, struct file *filp,
poll_table *wait)
{
struct n_hdlc *n_hdlc = tty2n_hdlc (tty);
unsigned int mask = 0;
if (debuglevel >= DEBUG_LEVEL_INFO)
printk("%s(%d)n_hdlc_tty_poll() called\n",__FILE__,__LINE__);
if (n_hdlc && n_hdlc->magic == HDLC_MAGIC && tty == n_hdlc->tty) {
poll_wait(filp, &tty->read_wait, wait);
poll_wait(filp, &tty->write_wait, wait);
if (n_hdlc->rx_buf_list.head)
mask |= POLLIN | POLLRDNORM;
if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
mask |= POLLHUP;
if (tty_hung_up_p(filp))
mask |= POLLHUP;
if (!tty_is_writelocked(tty) &&
n_hdlc->tx_free_buf_list.head)
mask |= POLLOUT | POLLWRNORM;
}
return mask;
}