[patch 36/61] lock validator: special locking: serial

[Ingo Molnar]

From: Ingo Molnar <mingo@xxxxxxx>

teach special (dual-initialized) locking code to the lock validator.
Has no effect on non-lockdep kernels.

Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
Signed-off-by: Arjan van de Ven <arjan@xxxxxxxxxxxxxxx>
---
---
 drivers/serial/serial_core.c |   10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

Index: linux/drivers/serial/serial_core.c
===================================================================
--- linux.orig/drivers/serial/serial_core.c
+++ linux/drivers/serial/serial_core.c
@@ -1849,6 +1849,12 @@ static const struct baud_rates baud_rate
 	{      0, B38400  }
 };
 
+/*
+ * lockdep: port->lock is initialized in two places, but we
+ *          want only one lock-type:
+ */
+static struct lockdep_type_key port_lock_key;
+
 /**
  *	uart_set_options - setup the serial console parameters
  *	@port: pointer to the serial ports uart_port structure
@@ -1869,7 +1875,7 @@ uart_set_options(struct uart_port *port,
 	 * Ensure that the serial console lock is initialised
 	 * early.
 	 */
-	spin_lock_init(&port->lock);
+	spin_lock_init_key(&port->lock, &port_lock_key);
 
 	memset(&termios, 0, sizeof(struct termios));
 
@@ -2255,7 +2261,7 @@ int uart_add_one_port(struct uart_driver
 	 * initialised.
 	 */
 	if (!(uart_console(port) && (port->cons->flags & CON_ENABLED)))
-		spin_lock_init(&port->lock);
+		spin_lock_init_key(&port->lock, &port_lock_key);
 
 	uart_configure_port(drv, state, port);
 
-
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