hvc_console: Change an mb() to smp_mb() and add some comments
I remember some history on this barrier. There was a race between
open via /dev/console and the tty being fully setup. Its also why
there is a temporary variable and the global is assigned at the end
of the function.
Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/drivers/char/hvc_console.c b/drivers/char/hvc_console.c
index 5a8a4c2..f2685b7 100644
--- a/drivers/char/hvc_console.c
+++ b/drivers/char/hvc_console.c
@@ -876,8 +876,11 @@
goto stop_thread;
}
- /* FIXME: This mb() seems completely random. Remove it. */
- mb();
+ /*
+ * Make sure tty is fully registered before allowing it to be
+ * found by hvc_console_device.
+ */
+ smp_mb();
hvc_driver = drv;
return 0;