console: Introduce ->exit() callback

Some consoles might require special operations on unregistering.
For instance, serial console, when registered in the kernel,
keeps power on for entire time, until it gets unregistered.
Example of use:

	->setup(console):
		pm_runtime_get(...);

	->exit(console):
		pm_runtime_put(...);

For such cases to have a balance we would provide ->exit() callback.

Link: http://lkml.kernel.org/r/20200203133130.11591-7-andriy.shevchenko@linux.intel.com
To: linux-kernel@vger.kernel.org
To: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>

diff --git a/include/linux/console.h b/include/linux/console.h
index d09951d5a94e4aa6341086aa98e186af8f10ba8f..0cbd2a36aa00281c957faf74a26ec82ed3db9d2d 100644 (file)
--- a/include/linux/console.h
+++ b/include/linux/console.h
@@ -149,6 +149,7 @@ struct console {
        struct tty_driver *(*device)(struct console *, int *);
        void    (*unblank)(void);
        int     (*setup)(struct console *, char *);
+       int     (*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 f435a17ef988260e1eb630b8bd3dde844b4027b9..633f41a11d759c29adcabf3d9c4381a41c05d9ba 100644 (file)
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -2853,6 +2853,9 @@ int unregister_console(struct console *console)
        console_unlock();
        console_sysfs_notify();
 
+       if (console->exit)
+               res = console->exit(console);
+
        return res;
 
 out_disable_unlock: