1 files changed, 13 insertions, 16 deletions

diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index fc9dd5d45295da..893bc493f66252 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -612,13 +612,6 @@ int serial8250_em485_config(struct uart_port *port, struct ktermios *termios,
 {
 	struct uart_8250_port *up = up_to_u8250p(port);
 
-	/* pick sane settings if the user hasn't */
-	if (!!(rs485->flags & SER_RS485_RTS_ON_SEND) ==
-	    !!(rs485->flags & SER_RS485_RTS_AFTER_SEND)) {
-		rs485->flags |= SER_RS485_RTS_ON_SEND;
-		rs485->flags &= ~SER_RS485_RTS_AFTER_SEND;
-	}
-
 	/*
 	 * Both serial8250_em485_init() and serial8250_em485_destroy()
 	 * are idempotent.
@@ -1630,7 +1623,7 @@ static void serial8250_start_tx(struct uart_port *port)
 	/* Port locked to synchronize UART_IER access against the console. */
 	lockdep_assert_held_once(&port->lock);
 
-	if (!port->x_char && uart_circ_empty(&port->state->xmit))
+	if (!port->x_char && kfifo_is_empty(&port->state->port.xmit_fifo))
 		return;
 
 	serial8250_rpm_get_tx(up);
@@ -1778,7 +1771,7 @@ EXPORT_SYMBOL_GPL(serial8250_rx_chars);
 void serial8250_tx_chars(struct uart_8250_port *up)
 {
 	struct uart_port *port = &up->port;
-	struct circ_buf *xmit = &port->state->xmit;
+	struct tty_port *tport = &port->state->port;
 	int count;
 
 	if (port->x_char) {
@@ -1789,14 +1782,19 @@ void serial8250_tx_chars(struct uart_8250_port *up)
 		serial8250_stop_tx(port);
 		return;
 	}
-	if (uart_circ_empty(xmit)) {
+	if (kfifo_is_empty(&tport->xmit_fifo)) {
 		__stop_tx(up);
 		return;
 	}
 
 	count = up->tx_loadsz;
 	do {
-		serial_out(up, UART_TX, xmit->buf[xmit->tail]);
+		unsigned char c;
+
+		if (!uart_fifo_get(port, &c))
+			break;
+
+		serial_out(up, UART_TX, c);
 		if (up->bugs & UART_BUG_TXRACE) {
 			/*
 			 * The Aspeed BMC virtual UARTs have a bug where data
@@ -1809,9 +1807,7 @@ void serial8250_tx_chars(struct uart_8250_port *up)
 			 */
 			serial_in(up, UART_SCR);
 		}
-		uart_xmit_advance(port, 1);
-		if (uart_circ_empty(xmit))
-			break;
+
 		if ((up->capabilities & UART_CAP_HFIFO) &&
 		    !uart_lsr_tx_empty(serial_in(up, UART_LSR)))
 			break;
@@ -1821,7 +1817,7 @@ void serial8250_tx_chars(struct uart_8250_port *up)
 			break;
 	} while (--count > 0);
 
-	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+	if (kfifo_len(&tport->xmit_fifo) < WAKEUP_CHARS)
 		uart_write_wakeup(port);
 
 	/*
@@ -1829,7 +1825,8 @@ void serial8250_tx_chars(struct uart_8250_port *up)
 	 * HW can go idle. So we get here once again with empty FIFO and disable
 	 * the interrupt and RPM in __stop_tx()
 	 */
-	if (uart_circ_empty(xmit) && !(up->capabilities & UART_CAP_RPM))
+	if (kfifo_is_empty(&tport->xmit_fifo) &&
+	    !(up->capabilities & UART_CAP_RPM))
 		__stop_tx(up);
 }
 EXPORT_SYMBOL_GPL(serial8250_tx_chars);