Merge branch 'tty-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty into for-next

Conflicts:
	arch/arm64/kernel/early_printk.c

2 files changed, 20 insertions, 1 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 *)
  *