From: Ingo Molnar Teach special (dual-initialized) locking code to the lock validator. Has no effect on non-lockdep kernels. Signed-off-by: Ingo Molnar Signed-off-by: Arjan van de Ven Cc: Russell King Signed-off-by: Andrew Morton --- drivers/serial/serial_core.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff -puN drivers/serial/serial_core.c~lockdep-annotate-serial drivers/serial/serial_core.c --- a/drivers/serial/serial_core.c~lockdep-annotate-serial +++ a/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 @@ uart_set_options(struct uart_port *port, * early. */ spin_lock_init(&port->lock); + lockdep_set_class(&port->lock, &port_lock_key); memset(&termios, 0, sizeof(struct termios)); @@ -2247,8 +2254,10 @@ int uart_add_one_port(struct uart_driver * 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); _