4 files changed, 28 insertions, 3 deletions

diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index f729be981da0..7a15b5b24c0b 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -285,6 +285,22 @@ static inline int uart_poll_timeout(struct uart_port *port)
 /*
  * Console helpers.
  */
+struct earlycon_device {
+        struct console *con;
+        struct uart_port port;
+        char options[16];               /* e.g., 115200n8 */
+        unsigned int baud;
+};
+int setup_earlycon(char *buf, const char *match,
+                   int (*setup)(struct earlycon_device *, const char *));
+
+#define EARLYCON_DECLARE(name, func) \
+static int __init name ## _setup_earlycon(char *buf) \
+{ \
+        return setup_earlycon(buf, __stringify(name), func); \
+} \
+early_param("earlycon", name ## _setup_earlycon);
+
 struct uart_port *uart_get_console(struct uart_port *ports, int nr,
                                    struct console *c);
 void uart_parse_options(char *options, int *baud, int *parity, int *bits,
diff --git a/include/linux/tty_ldisc.h b/include/linux/tty_ldisc.h
index add26da2faeb..00c9d688d7b7 100644
--- a/include/linux/tty_ldisc.h
+++ b/include/linux/tty_ldisc.h
@@ -92,7 +92,10 @@
  *      This function is called by the low-level tty driver to signal
  *      that line discpline should try to send more characters to the
  *      low-level driver for transmission.  If the line discpline does
- *      not have any more data to send, it can just return.
+ *      not have any more data to send, it can just return. If the line
+ *      discipline does have some data to send, please arise a tasklet
+ *      or workqueue to do the real data transfer. Do not send data in
+ *      this hook, it may leads to a deadlock.
  *
  * int (*hangup)(struct tty_struct *)
  *
diff --git a/include/uapi/linux/serial_core.h b/include/uapi/linux/serial_core.h
index b47dba2c1e6f..5820269aa132 100644
--- a/include/uapi/linux/serial_core.h
+++ b/include/uapi/linux/serial_core.h
@@ -211,7 +211,7 @@
 /* VIA VT8500 SoC */
 #define PORT_VT8500     97
 
-/* Xilinx PSS UART */
+/* Cadence (Xilinx Zynq) UART */
 #define PORT_XUARTPS    98
 
 /* Atheros AR933X SoC */
@@ -238,4 +238,10 @@
 /* Tilera TILE-Gx UART */
 #define PORT_TILEGX     106
 
+/* MEN 16z135 UART */
+#define PORT_MEN_Z135   107
+
+/* SC16IS74xx */
+#define PORT_SC16IS7XX   108
+
 #endif /* _UAPILINUX_SERIAL_CORE_H */
diff --git a/include/uapi/linux/serial_reg.h b/include/uapi/linux/serial_reg.h
index e6322605b138..99b47058816a 100644
--- a/include/uapi/linux/serial_reg.h
+++ b/include/uapi/linux/serial_reg.h
@@ -32,7 +32,7 @@
 
 #define UART_IIR        2       /* In:  Interrupt ID Register */
 #define UART_IIR_NO_INT         0x01 /* No interrupts pending */
-#define UART_IIR_ID             0x06 /* Mask for the interrupt ID */
+#define UART_IIR_ID             0x0e /* Mask for the interrupt ID */
 #define UART_IIR_MSI            0x00 /* Modem status interrupt */
 #define UART_IIR_THRI           0x02 /* Transmitter holding register empty */
 #define UART_IIR_RDI            0x04 /* Receiver data interrupt */