From: Johan Hovold <jhovold@gmail.com>
Date: Mon, 14 Jan 2013 15:52:57 +0000 (+0100)
Subject: USB: io_ti: query hardware-buffer status in chars_in_buffer
X-Git-Tag: v3.9-rc1~126^2~62
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=263e1f9fbb999fb78df5bfed87ddbba1c12ee0f1;p=platform%2Fkernel%2Flinux-3.10.git

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>
---

diff --git a/drivers/usb/serial/io_ti.c b/drivers/usb/serial/io_ti.c
index 3abbdaa..590f27d 100644
--- a/drivers/usb/serial/io_ti.c
+++ b/drivers/usb/serial/io_ti.c
@@ -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;
 }