Patch "tty: goldfish: Enable 'earlycon' only if built-in" has been added to the 4.15-stable tree

This is a note to let you know that I've just added the patch titled

tty: goldfish: Enable 'earlycon' only if built-in

to the 4.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
tty-goldfish-enable-earlycon-only-if-built-in.patch
and it can be found in the queue-4.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Sebastian Andrzej Siewior <[email protected]>
Date: Thu, 30 Nov 2017 09:16:31 +0100
Subject: tty: goldfish: Enable 'earlycon' only if built-in

From: Sebastian Andrzej Siewior <[email protected]>

[ Upstream commit 6a28fd2bbc94bfca105632e5ef8a9dbe63ba0b39 ]

Commit 3840ed9548f7 ("tty: goldfish: Implement support for kernel 'earlycon' parameter") breaks an allmodconfig config on x86:

|  LD      vmlinux.o
|  MODPOST vmlinux.o
|drivers/tty/serial/earlycon.o: In function `parse_options':
|drivers/tty/serial/earlycon.c:97: undefined reference to `uart_parse_earlycon'
|Makefile:1005: recipe for target 'vmlinux' failed

earlycon.c::parse_options() invokes uart_parse_earlycon() from serial_core.c which is compiled=m because GOLDFISH_TTY itself (and most others) are =m. To avoid that, I'm adding the _CONSOLE config option which is selected if the GOLDFISH module itself is =y since it doesn't need the early bits for the =m case (other drivers do the same dance).
The alternative would be to move uart_parse_earlycon() from serial_core.c to earlycon.c (we don't have that many users of that function).

'earlycon' parameter")

---
 drivers/tty/Kconfig    |    6 +++++-
 drivers/tty/goldfish.c |    2 ++
 2 files changed, 7 insertions(+), 1 deletion(-)

@@ -394,10 +394,14 @@ config GOLDFISH_TTY
 	depends on GOLDFISH
 	select SERIAL_CORE
 	select SERIAL_CORE_CONSOLE
-	select SERIAL_EARLYCON
 	help
 	  Console and system TTY driver for the Goldfish virtual platform.
 
+config GOLDFISH_TTY_EARLY_CONSOLE
+	bool
+	default y if GOLDFISH_TTY=y
+	select SERIAL_EARLYCON
+
 config DA_TTY
 	bool "DA TTY"
 	depends on METAG_DA

@@ -433,6 +433,7 @@ static int goldfish_tty_remove(struct pl
 	return 0;
 }
 
+#ifdef CONFIG_GOLDFISH_TTY_EARLY_CONSOLE
 static void gf_early_console_putchar(struct uart_port *port, int ch)
 {
 	__raw_writel(ch, port->membase);

@@ -456,6 +457,7 @@ static int __init gf_earlycon_setup(stru
 }
 
 OF_EARLYCON_DECLARE(early_gf_tty, "google,goldfish-tty", gf_earlycon_setup);
+#endif
 
 static const struct of_device_id goldfish_tty_of_match[] = {
 	{ .compatible = "google,goldfish-tty", },

Patches currently in stable-queue which might be from [email protected] are

queue-4.15/tty-goldfish-enable-earlycon-only-if-built-in.patch