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authorJohan Hovold <jhovold@gmail.com>2013-04-18 17:33:21 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-04-19 10:24:13 -0700
commit2c992cd73772bd0ef107536e8e3399d28493caa8 (patch)
treef596c0810ab88d2c468140931e806bca40c3f067 /drivers/usb/serial/ti_usb_3410_5052.c
parentb5784f7d8528926d69c5868f1ddb2af99f85e799 (diff)
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: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/serial/ti_usb_3410_5052.c')
-rw-r--r--drivers/usb/serial/ti_usb_3410_5052.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/usb/serial/ti_usb_3410_5052.c b/drivers/usb/serial/ti_usb_3410_5052.c
index 3ed8ecafe597..062b6d872ea3 100644
--- a/drivers/usb/serial/ti_usb_3410_5052.c
+++ b/drivers/usb/serial/ti_usb_3410_5052.c
@@ -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;
}