[PATCH] lockdep: annotate serial
Teach special (dual-initialized) locking code to the lock validator. Has no
effect on non-lockdep kernels.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index c54af877..9583180 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -49,6 +49,12 @@
*/
static DEFINE_MUTEX(port_mutex);
+/*
+ * lockdep: port->lock is initialized in two places, but we
+ * want only one lock-class:
+ */
+static struct lock_class_key port_lock_key;
+
#define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
#define uart_users(state) ((state)->count + ((state)->info ? (state)->info->blocked_open : 0))
@@ -1865,6 +1871,7 @@
* early.
*/
spin_lock_init(&port->lock);
+ lockdep_set_class(&port->lock, &port_lock_key);
memset(&termios, 0, sizeof(struct termios));
@@ -2247,8 +2254,10 @@
* If this port is a console, then the spinlock is already
* initialised.
*/
- if (!(uart_console(port) && (port->cons->flags & CON_ENABLED)))
+ if (!(uart_console(port) && (port->cons->flags & CON_ENABLED))) {
spin_lock_init(&port->lock);
+ lockdep_set_class(&port->lock, &port_lock_key);
+ }
uart_configure_port(drv, state, port);