serial: tegra: report error to upper tty layer

Report overrun/parity/frame/break errors to top tty layer. Add support
to ignore break character if IGNBRK is set.

Signed-off-by: Shardar Shariff Md <smohammed@nvidia.com>
Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com>
Link: https://lore.kernel.org/r/1567572187-29820-5-git-send-email-kyarlagadda@nvidia.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/serial-tegra.c

@@ -373,13 +373,21 @@ static char tegra_uart_decode_rx_error(struct tegra_uart_port *tup,
 			tup->uport.icount.frame++;
 			dev_err(tup->uport.dev, "Got frame errors\n");
 		} else if (lsr & UART_LSR_BI) {
-			dev_err(tup->uport.dev, "Got Break\n");
-			tup->uport.icount.brk++;
-			/* If FIFO read error without any data, reset Rx FIFO */
+			/*
+			 * Break error
+			 * If FIFO read error without any data, reset Rx FIFO
+			 */
 			if (!(lsr & UART_LSR_DR) && (lsr & UART_LSR_FIFOE))
 				tegra_uart_fifo_reset(tup, UART_FCR_CLEAR_RCVR);
+			if (tup->uport.ignore_status_mask & UART_LSR_BI)
+				return TTY_BREAK;
+			flag = TTY_BREAK;
+			tup->uport.icount.brk++;
+			dev_dbg(tup->uport.dev, "Got Break\n");
 		}
+		uart_insert_char(&tup->uport, lsr, UART_LSR_OE, 0, flag);
 	}
+
 	return flag;
 }
 
@@ -561,6 +569,9 @@ static void tegra_uart_handle_rx_pio(struct tegra_uart_port *tup,
 			break;
 
 		flag = tegra_uart_decode_rx_error(tup, lsr);
+		if (flag != TTY_NORMAL)
+			continue;
+
 		ch = (unsigned char) tegra_uart_read(tup, UART_RX);
 		tup->uport.icount.rx++;
 
@@ -1223,6 +1234,8 @@ static void tegra_uart_set_termios(struct uart_port *u,
 	/* Ignore all characters if CREAD is not set */
 	if ((termios->c_cflag & CREAD) == 0)
 		tup->uport.ignore_status_mask |= UART_LSR_DR;
+	if (termios->c_iflag & IGNBRK)
+		tup->uport.ignore_status_mask |= UART_LSR_BI;
 
 	spin_unlock_irqrestore(&u->lock, flags);
 }