USB: io_ti: query hardware-buffer status in chars_in_buffer

Query hardware-buffer status in chars_in_buffer should the write fifo be
empty.

This is needed to make the tty layer wait for hardware buffers to drain
on close.

Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Johan Hovold 2013-01-14 16:52:57 +01:00 committed by Greg Kroah-Hartman
parent 810360a035
commit 263e1f9fbb
1 changed files with 7 additions and 0 deletions

View File

@ -2088,6 +2088,7 @@ static int edge_chars_in_buffer(struct tty_struct *tty)
struct edgeport_port *edge_port = usb_get_serial_port_data(port);
int chars = 0;
unsigned long flags;
int ret;
if (edge_port == NULL)
return 0;
@ -2098,6 +2099,12 @@ static int edge_chars_in_buffer(struct tty_struct *tty)
chars = kfifo_len(&edge_port->write_fifo);
spin_unlock_irqrestore(&edge_port->ep_lock, flags);
if (!chars) {
ret = tx_active(edge_port);
if (ret > 0)
chars = ret;
}
dev_dbg(&port->dev, "%s - returns %d\n", __func__, chars);
return chars;
}