--- zzzz-none-000/linux-3.10.107/drivers/tty/serial/m32r_sio.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/drivers/tty/serial/m32r_sio.c	2021-02-04 17:41:59.000000000 +0000
@@ -249,7 +249,8 @@
 
 static void m32r_sio_stop_tx(struct uart_port *port)
 {
-	struct uart_sio_port *up = (struct uart_sio_port *)port;
+	struct uart_sio_port *up =
+		container_of(port, struct uart_sio_port, port);
 
 	if (up->ier & UART_IER_THRI) {
 		up->ier &= ~UART_IER_THRI;
@@ -260,19 +261,23 @@
 static void m32r_sio_start_tx(struct uart_port *port)
 {
 #ifdef CONFIG_SERIAL_M32R_PLDSIO
-	struct uart_sio_port *up = (struct uart_sio_port *)port;
+	struct uart_sio_port *up =
+		container_of(port, struct uart_sio_port, port);
 	struct circ_buf *xmit = &up->port.state->xmit;
 
 	if (!(up->ier & UART_IER_THRI)) {
 		up->ier |= UART_IER_THRI;
 		serial_out(up, UART_IER, up->ier);
-		serial_out(up, UART_TX, xmit->buf[xmit->tail]);
-		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
-		up->port.icount.tx++;
+		if (!uart_circ_empty(xmit)) {
+			serial_out(up, UART_TX, xmit->buf[xmit->tail]);
+			xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+			up->port.icount.tx++;
+		}
 	}
 	while((serial_in(up, UART_LSR) & UART_EMPTY) != UART_EMPTY);
 #else
-	struct uart_sio_port *up = (struct uart_sio_port *)port;
+	struct uart_sio_port *up =
+		container_of(port, struct uart_sio_port, port);
 
 	if (!(up->ier & UART_IER_THRI)) {
 		up->ier |= UART_IER_THRI;
@@ -283,7 +288,8 @@
 
 static void m32r_sio_stop_rx(struct uart_port *port)
 {
-	struct uart_sio_port *up = (struct uart_sio_port *)port;
+	struct uart_sio_port *up =
+		container_of(port, struct uart_sio_port, port);
 
 	up->ier &= ~UART_IER_RLSI;
 	up->port.read_status_mask &= ~UART_LSR_DR;
@@ -292,7 +298,8 @@
 
 static void m32r_sio_enable_ms(struct uart_port *port)
 {
-	struct uart_sio_port *up = (struct uart_sio_port *)port;
+	struct uart_sio_port *up =
+		container_of(port, struct uart_sio_port, port);
 
 	up->ier |= UART_IER_MSI;
 	serial_out(up, UART_IER, up->ier);
@@ -368,7 +375,10 @@
 	ignore_char:
 		*status = serial_in(up, UART_LSR);
 	} while ((*status & UART_LSR_DR) && (max_count-- > 0));
+
+	spin_unlock(&up->port.lock);
 	tty_flip_buffer_push(port);
+	spin_lock(&up->port.lock);
 }
 
 static void transmit_chars(struct uart_sio_port *up)
@@ -576,7 +586,8 @@
 
 static unsigned int m32r_sio_tx_empty(struct uart_port *port)
 {
-	struct uart_sio_port *up = (struct uart_sio_port *)port;
+	struct uart_sio_port *up =
+		container_of(port, struct uart_sio_port, port);
 	unsigned long flags;
 	unsigned int ret;
 
@@ -604,7 +615,8 @@
 
 static int m32r_sio_startup(struct uart_port *port)
 {
-	struct uart_sio_port *up = (struct uart_sio_port *)port;
+	struct uart_sio_port *up =
+		container_of(port, struct uart_sio_port, port);
 	int retval;
 
 	sio_init();
@@ -647,7 +659,8 @@
 
 static void m32r_sio_shutdown(struct uart_port *port)
 {
-	struct uart_sio_port *up = (struct uart_sio_port *)port;
+	struct uart_sio_port *up =
+		container_of(port, struct uart_sio_port, port);
 
 	/*
 	 * Disable interrupts from this port
@@ -676,7 +689,8 @@
 static void m32r_sio_set_termios(struct uart_port *port,
 	struct ktermios *termios, struct ktermios *old)
 {
-	struct uart_sio_port *up = (struct uart_sio_port *)port;
+	struct uart_sio_port *up =
+		container_of(port, struct uart_sio_port, port);
 	unsigned char cval = 0;
 	unsigned long flags;
 	unsigned int baud, quot;
@@ -734,7 +748,7 @@
 	up->port.read_status_mask = UART_LSR_OE | UART_LSR_THRE | UART_LSR_DR;
 	if (termios->c_iflag & INPCK)
 		up->port.read_status_mask |= UART_LSR_FE | UART_LSR_PE;
-	if (termios->c_iflag & (BRKINT | PARMRK))
+	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
 		up->port.read_status_mask |= UART_LSR_BI;
 
 	/*
@@ -775,7 +789,8 @@
 static void m32r_sio_pm(struct uart_port *port, unsigned int state,
 	unsigned int oldstate)
 {
-	struct uart_sio_port *up = (struct uart_sio_port *)port;
+	struct uart_sio_port *up =
+		container_of(port, struct uart_sio_port, port);
 
 	if (up->pm)
 		up->pm(port, state, oldstate);
@@ -820,7 +835,8 @@
 
 static void m32r_sio_release_port(struct uart_port *port)
 {
-	struct uart_sio_port *up = (struct uart_sio_port *)port;
+	struct uart_sio_port *up =
+		container_of(port, struct uart_sio_port, port);
 	unsigned long start, offset = 0, size = 0;
 
 	size <<= up->port.regshift;
@@ -857,7 +873,8 @@
 
 static int m32r_sio_request_port(struct uart_port *port)
 {
-	struct uart_sio_port *up = (struct uart_sio_port *)port;
+	struct uart_sio_port *up =
+		container_of(port, struct uart_sio_port, port);
 	struct resource *res = NULL;
 	int ret = 0;
 
@@ -884,7 +901,8 @@
 
 static void m32r_sio_config_port(struct uart_port *port, int unused)
 {
-	struct uart_sio_port *up = (struct uart_sio_port *)port;
+	struct uart_sio_port *up =
+		container_of(port, struct uart_sio_port, port);
 	unsigned long flags;
 
 	spin_lock_irqsave(&up->port.lock, flags);
@@ -995,7 +1013,8 @@
 
 static void m32r_sio_console_putchar(struct uart_port *port, int ch)
 {
-	struct uart_sio_port *up = (struct uart_sio_port *)port;
+	struct uart_sio_port *up =
+		container_of(port, struct uart_sio_port, port);
 
 	wait_for_xmitr(up);
 	sio_out(up, SIOTXB, ch);