Initial commit

target/linux/generic/pending-4.9/890-uart_optional_sysrq.patch

@@ -0,0 +1,40 @@
+From: John Crispin <john@phrozen.org>
+Subject: serial: do not accept sysrq characters via serial port
+
+many embedded boards have a disconnected TTL level serial which can
+generate some garbage that can lead to spurious false sysrq detects.
+
+[john@phrozen.org: sent upstream 22.12.2016]
+
+Signed-off-by: John Crispin <john@phrozen.org>
+Signed-off-by: Felix Fietkau <nbd@nbd.name>
+---
+ include/linux/serial_core.h | 2 +-
+ lib/Kconfig.debug           | 5 +++++
+ 2 files changed, 6 insertions(+), 1 deletion(-)
+
+--- a/include/linux/serial_core.h
++++ b/include/linux/serial_core.h
+@@ -457,7 +457,7 @@ extern void uart_handle_cts_change(struc
+ extern void uart_insert_char(struct uart_port *port, unsigned int status,
+ 		 unsigned int overrun, unsigned int ch, unsigned int flag);
+ 
+-#ifdef SUPPORT_SYSRQ
++#if defined(SUPPORT_SYSRQ) && defined(CONFIG_MAGIC_SYSRQ_SERIAL)
+ static inline int
+ uart_handle_sysrq_char(struct uart_port *port, unsigned int ch)
+ {
+--- a/lib/Kconfig.debug
++++ b/lib/Kconfig.debug
+@@ -410,6 +410,11 @@ config MAGIC_SYSRQ_DEFAULT_ENABLE
+ 	  This may be set to 1 or 0 to enable or disable them all, or
+ 	  to a bitmask as described in Documentation/sysrq.txt.
+ 
++config MAGIC_SYSRQ_SERIAL
++	bool "Enable magic SysRq key over serial"
++	depends on MAGIC_SYSRQ
++	default y
++
+ config DEBUG_KERNEL
+ 	bool "Kernel debugging"
+ 	help