[PATCH v3 1/4] tty: serial: move and cleanup vt8500_tx_empty()

[Jiri Slaby <jslaby@suse.cz>]

Make vt8500_tx_empty() more readable by introducing a new local variable
and move the function before handle_tx(). That way we can reuse it in
there too.

Cc: <linux-arm-kernel@lists.infradead.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---

Notes:
    [v3] this is new in v3 -- extracted as a separate change from later
         patches

 drivers/tty/serial/vt8500_serial.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/drivers/tty/serial/vt8500_serial.c b/drivers/tty/serial/vt8500_serial.c
index 6f08136ce78a..9e2c745b4535 100644
--- a/drivers/tty/serial/vt8500_serial.c
+++ b/drivers/tty/serial/vt8500_serial.c
@@ -187,6 +187,13 @@ static void handle_rx(struct uart_port *port)
 	tty_flip_buffer_push(tport);
 }
 
+static unsigned int vt8500_tx_empty(struct uart_port *port)
+{
+	unsigned int idx = vt8500_read(port, VT8500_URFIDX) & 0x1f;
+
+	return idx < 16 ? TIOCSER_TEMT : 0;
+}
+
 static void handle_tx(struct uart_port *port)
 {
 	struct circ_buf *xmit = &port->state->xmit;
@@ -201,7 +208,7 @@ static void handle_tx(struct uart_port *port)
 		return;
 	}
 
-	while ((vt8500_read(port, VT8500_URFIDX) & 0x1f) < 16) {
+	while (vt8500_tx_empty(port)) {
 		if (uart_circ_empty(xmit))
 			break;
 
@@ -260,12 +267,6 @@ static irqreturn_t vt8500_irq(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
-static unsigned int vt8500_tx_empty(struct uart_port *port)
-{
-	return (vt8500_read(port, VT8500_URFIDX) & 0x1f) < 16 ?
-						TIOCSER_TEMT : 0;
-}
-
 static unsigned int vt8500_get_mctrl(struct uart_port *port)
 {
 	unsigned int usr;
-- 
2.37.3