[PATCH v2 04/12] USB: serial: io_edgeport: move initial termios update to open()

[Johan Hovold <johan@kernel.org>]

Explicitly update the terminal settings on open() instead of doing so
from the interrupt completion handler when receiving an open command
response, which in theory can be received after a failed open attempt.

Note that this will be used to fix a FIFO corruption issue and also
allows for switching to synchronous commands.

Cc: stable@vger.kernel.org
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/usb/serial/io_edgeport.c | 64 +++++---------------------------
 1 file changed, 10 insertions(+), 54 deletions(-)

diff --git a/drivers/usb/serial/io_edgeport.c b/drivers/usb/serial/io_edgeport.c
index e8e641e9a197..cdcff02c435b 100644
--- a/drivers/usb/serial/io_edgeport.c
+++ b/drivers/usb/serial/io_edgeport.c
@@ -281,8 +281,7 @@ static void handle_new_lsr(struct edgeport_port *edge_port, __u8 lsrData,
 static int  send_iosp_ext_cmd(struct edgeport_port *edge_port, __u8 command,
 				__u8 param);
 static int  calc_baud_rate_divisor(struct device *dev, int baud_rate, int *divisor);
-static void change_port_settings(struct tty_struct *tty,
-				struct edgeport_port *edge_port,
+static void edge_set_termios(struct tty_struct *tty, struct usb_serial_port *port,
 				const struct ktermios *old_termios);
 static int  send_cmd_write_uart_register(struct edgeport_port *edge_port,
 				__u8 regNum, __u8 regValue);
@@ -923,6 +922,9 @@ static int edge_open(struct tty_struct *tty, struct usb_serial_port *port)
 		return -ENOMEM;
 	}
 
+	if (tty)
+		edge_set_termios(tty, port, NULL);
+
 	spin_lock_irq(&edge_port->ep_lock);
 	edge_port->open = true;
 	spin_unlock_irq(&edge_port->ep_lock);
@@ -1443,30 +1445,6 @@ static void edge_unthrottle(struct tty_struct *tty)
 }
 
 
-/*****************************************************************************
- * SerialSetTermios
- *	this function is called by the tty driver when it wants to change
- * the termios structure
- *****************************************************************************/
-static void edge_set_termios(struct tty_struct *tty,
-			     struct usb_serial_port *port,
-			     const struct ktermios *old_termios)
-{
-	struct edgeport_port *edge_port = usb_get_serial_port_data(port);
-
-	if (edge_port == NULL)
-		return;
-
-	if (!edge_port->open) {
-		dev_dbg(&port->dev, "%s - port not opened\n", __func__);
-		return;
-	}
-
-	/* change the port settings to the new ones specified */
-	change_port_settings(tty, edge_port, old_termios);
-}
-
-
 /*****************************************************************************
  * get_lsr_info - get line status register info
  *
@@ -1756,7 +1734,6 @@ static void process_rcvd_status(struct edgeport_serial *edge_serial,
 {
 	struct usb_serial_port *port;
 	struct edgeport_port *edge_port;
-	struct tty_struct *tty;
 	struct device *dev;
 	__u8 code = edge_serial->rxStatusCode;
 
@@ -1808,15 +1785,6 @@ static void process_rcvd_status(struct edgeport_serial *edge_serial,
 			__func__, edge_serial->rxPort, byte2, edge_port->txCredits);
 		handle_new_msr(edge_port, byte2);
 
-		/* send the current line settings to the port so we are
-		   in sync with any further termios calls */
-		tty = tty_port_tty_get(&edge_port->port->port);
-		if (tty) {
-			change_port_settings(tty,
-				edge_port, &tty->termios);
-			tty_kref_put(tty);
-		}
-
 		/* we have completed the open */
 		edge_port->openPending = false;
 		wake_up(&edge_port->wait_open);
@@ -2328,18 +2296,12 @@ static int send_cmd_write_uart_register(struct edgeport_port *edge_port,
 }
 
 
-/*****************************************************************************
- * change_port_settings
- *	This routine is called to set the UART on the device to match the
- *	specified new settings.
- *****************************************************************************/
-
-static void change_port_settings(struct tty_struct *tty,
-	struct edgeport_port *edge_port, const struct ktermios *old_termios)
+static void edge_set_termios(struct tty_struct *tty, struct usb_serial_port *port,
+		const struct ktermios *old_termios)
 {
-	struct device *dev = &edge_port->port->dev;
-	struct edgeport_serial *edge_serial =
-			usb_get_serial_data(edge_port->port->serial);
+	struct edgeport_serial *edge_serial = usb_get_serial_data(port->serial);
+	struct edgeport_port *edge_port = usb_get_serial_port_data(port);
+	struct device *dev = &port->dev;
 	int baud;
 	unsigned cflag;
 	__u8 mask = 0xff;
@@ -2350,12 +2312,6 @@ static void change_port_settings(struct tty_struct *tty,
 	__u8 txFlow;
 	int status;
 
-	if (!edge_port->open &&
-	    !edge_port->openPending) {
-		dev_dbg(dev, "%s - port not opened\n", __func__);
-		return;
-	}
-
 	cflag = tty->termios.c_cflag;
 
 	switch (cflag & CSIZE) {
@@ -2489,7 +2445,7 @@ static void change_port_settings(struct tty_struct *tty,
 
 	dev_dbg(dev, "%s - baud rate = %d\n", __func__, baud);
 	status = send_cmd_write_baud_rate(edge_port, baud);
-	if (status == -1) {
+	if (status == -1 && old_termios) {
 		/* Speed change was not possible - put back the old speed */
 		baud = tty_termios_baud_rate(old_termios);
 		tty_encode_baud_rate(tty, baud, baud);
-- 
2.55.0