Add wait_until_sent operation which can be used to wait for hardware
buffers to drain.
Signed-off-by: Johan Hovold <jhovold@xxxxxxxxx>
---
drivers/usb/serial/usb-serial.c | 17 +++++++++++++++++
include/linux/usb/serial.h | 1 +
2 files changed, 18 insertions(+)
diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index cf75beb..31d2768 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -375,6 +375,22 @@ static int serial_chars_in_buffer(struct tty_struct *tty)
return count;
}
+static void serial_wait_until_sent(struct tty_struct *tty, int timeout)
+{
+ struct usb_serial_port *port = tty->driver_data;
+ struct usb_serial *serial = port->serial;
+
+ dev_dbg(tty->dev, "%s\n", __func__);
+
+ if (!port->serial->type->wait_until_sent)
+ return;
+
+ mutex_lock(&serial->disc_mutex);
+ if (!serial->disconnected)
+ port->serial->type->wait_until_sent(tty, timeout);
+ mutex_unlock(&serial->disc_mutex);
+}
+
static void serial_throttle(struct tty_struct *tty)
{
struct usb_serial_port *port = tty->driver_data;
@@ -1191,6 +1207,7 @@ static const struct tty_operations serial_ops = {
.unthrottle = serial_unthrottle,
.break_ctl = serial_break,
.chars_in_buffer = serial_chars_in_buffer,
+ .wait_until_sent = serial_wait_until_sent,
.tiocmget = serial_tiocmget,
.tiocmset = serial_tiocmset,
.get_icount = serial_get_icount,
diff --git a/include/linux/usb/serial.h b/include/linux/usb/serial.h
index b9b0f7b4..afbb7ee 100644
--- a/include/linux/usb/serial.h
+++ b/include/linux/usb/serial.h
@@ -268,6 +268,7 @@ struct usb_serial_driver {
struct usb_serial_port *port, struct ktermios *old);
void (*break_ctl)(struct tty_struct *tty, int break_state);
int (*chars_in_buffer)(struct tty_struct *tty);
+ void (*wait_until_sent)(struct tty_struct *tty, long timeout);
void (*throttle)(struct tty_struct *tty);
void (*unthrottle)(struct tty_struct *tty);
int (*tiocmget)(struct tty_struct *tty);
--
1.8.2.1
--
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