openwrt/target/linux/layerscape/patches-5.4/819-uart-0003-tty-serial-fsl_lpuart-add-magic-SysRq-support.patch

From 74d7e639cce7ae95cacd948dcf5ed3b28c3fff5c Mon Sep 17 00:00:00 2001
From: Fugang Duan <fugang.duan@nxp.com>
Date: Mon, 28 Jan 2019 10:27:27 +0800
Subject: [PATCH] tty: serial: fsl_lpuart: add magic SysRq support

Add magic SysRq key support.

Signed-off-by: Fugang Duan <fugang.duan@nxp.com>
---
 drivers/tty/serial/fsl_lpuart.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -931,7 +931,12 @@ static void lpuart32_rxint(struct lpuart
 		 */
 		sr = lpuart32_read(&sport->port, UARTSTAT);
 		rx = lpuart32_read(&sport->port, UARTDATA);
-		rx &= 0x3ff;
+
+		if ((sr & UARTSTAT_FE) && (rx & UARTDATA_FRETSC) &&
+			!(rx & UARTDATA_MASK)) {
+			if (uart_handle_break(&sport->port))
+				continue;
+		}
 
 		if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx))
 			continue;