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Commit 2c992cd7 authored by Johan Hovold's avatar Johan Hovold Committed by Greg Kroah-Hartman
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USB: ti_usb_3410_5052: 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: default avatarJohan Hovold <jhovold@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent b5784f7d

drivers/usb/serial/ti_usb_3410_5052.c

+8 −0
Original line number Diff line number Diff line
@@ -687,6 +687,8 @@ static int ti_chars_in_buffer(struct tty_struct *tty) 
	struct ti_port *tport = usb_get_serial_port_data(port);

	int chars = 0;

	unsigned long flags;

	int ret;

	u8 lsr;



	if (tport == NULL)

		return 0;
@@ -695,6 +697,12 @@ static int ti_chars_in_buffer(struct tty_struct *tty) 
	chars = kfifo_len(&tport->write_fifo);

	spin_unlock_irqrestore(&tport->tp_lock, flags);



	if (!chars) {

		ret = ti_get_lsr(tport, &lsr);

		if (!ret && !(lsr & TI_LSR_TX_EMPTY))

			chars = 1;

	}



	dev_dbg(&port->dev, "%s - returns %d\n", __func__, chars);

	return chars;

}