tty: Document locking for tty driver methods
The tty core calls the tty driver's open, close and hangup
methods holding the tty lock.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/include/linux/tty_driver.h b/include/linux/tty_driver.h
index 756a609..e48c608 100644
--- a/include/linux/tty_driver.h
+++ b/include/linux/tty_driver.h
@@ -35,14 +35,14 @@
* This routine is mandatory; if this routine is not filled in,
* the attempted open will fail with ENODEV.
*
- * Required method.
- *
+ * Required method. Called with tty lock held.
+ *
* void (*close)(struct tty_struct * tty, struct file * filp);
*
* This routine is called when a particular tty device is closed.
* Note: called even if the corresponding open() failed.
*
- * Required method.
+ * Required method. Called with tty lock held.
*
* void (*shutdown)(struct tty_struct * tty);
*
@@ -172,6 +172,8 @@
*
* Optional:
*
+ * Called with tty lock held.
+ *
* int (*break_ctl)(struct tty_struct *tty, int state);
*
* This optional routine requests the tty driver to turn on or