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From:   Krishna Yarlagadda <kyarlagadda@nvidia.com>
To:     <gregkh@linuxfoundation.org>, <robh+dt@kernel.org>,
        <mark.rutland@arm.com>, <thierry.reding@gmail.com>,
        <jonathanh@nvidia.com>, <ldewangan@nvidia.com>, <jslaby@suse.com>
CC:     <linux-serial@vger.kernel.org>, <devicetree@vger.kernel.org>,
        <linux-tegra@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        "Krishna Yarlagadda" <kyarlagadda@nvidia.com>,
        Shardar Shariff Md <smohammed@nvidia.com>
Subject: [PATCH 06/14] serial: tegra: report error to upper tty layer
Date:   Mon, 12 Aug 2019 16:58:15 +0530
Message-ID: <1565609303-27000-7-git-send-email-kyarlagadda@nvidia.com>
In-Reply-To: <1565609303-27000-1-git-send-email-kyarlagadda@nvidia.com>
References: <1565609303-27000-1-git-send-email-kyarlagadda@nvidia.com>
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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>
---
 drivers/tty/serial/serial-tegra.c | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/drivers/tty/serial/serial-tegra.c b/drivers/tty/serial/serial-tegra.c
index f6a3f4e..7ab81bb 100644
--- a/drivers/tty/serial/serial-tegra.c
+++ b/drivers/tty/serial/serial-tegra.c
@@ -374,13 +374,21 @@ 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_err(tup->uport.dev, "Got Break\n");
 		}
+		uart_insert_char(&tup->uport, lsr, UART_LSR_OE, 0, flag);
 	}
+
 	return flag;
 }
 
@@ -562,6 +570,9 @@ 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++;
 
@@ -1224,6 +1235,8 @@ 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);
 }
-- 
2.7.4