[PATCH v3 5/5] console: Introduce ->exit() callback

[Andy Shevchenko <andriy.shevchenko@linux.intel.com>]

Some consoles might require special operations on unregistering. For example,
serial console, when registered in the kernel, keeps power on for entire time,
until it gets unregistered. For such cases to have a balance we would provide
->exit() callback.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
v3: move callback out from console_lock (Sergey)
 include/linux/console.h | 1 +
 kernel/printk/printk.c  | 4 ++++
 2 files changed, 5 insertions(+)

diff --git a/include/linux/console.h b/include/linux/console.h
index f33016b3a401..54759ad0c36b 100644
--- a/include/linux/console.h
+++ b/include/linux/console.h
@@ -148,6 +148,7 @@ struct console {
 	struct tty_driver *(*device)(struct console *, int *);
 	void	(*unblank)(void);
 	int	(*setup)(struct console *, char *);
+	void	(*exit)(struct console *);
 	int	(*match)(struct console *, char *name, int idx, char *options);
 	short	flags;
 	short	index;
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index da6a9bdf76b6..6ca03d199132 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -2853,6 +2853,10 @@ int unregister_console(struct console *console)
 	console->flags &= ~CON_ENABLED;
 	console_unlock();
 	console_sysfs_notify();
+
+	if (console->exit)
+		console->exit(console);
+
 	return res;
 }
 EXPORT_SYMBOL(unregister_console);
-- 
2.24.1