[PATCH] serial: initialize spinlock for port failed to setupconsole

[Atsushi Nemoto]

It seems serial_core intend to initialize port->lock just once for
each ports.  This is done in uart_set_options() for console, and in
uart_add_one_port() for other ports.  But there is a case the
port->lock is not initialized by serial_core.  If the setup function
for the console was failed, it will not call uart_set_options() but
the port is marked as console (uart_console(port) returns 1).  It can
happen if console was PCI port which can not detected at the time of
register_console.

This patch is to initialize port->lock for such console port.  With
this change, most of spin_lock_init() (some of them are labeled
"Temporary fix.") in low-level serial drivers can be omitted.

Signed-off-by: Atsushi Nemoto <anemo@xxxxxxxxxxxxx>

diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index 9437704..211701d 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -2235,7 +2235,7 @@ int uart_add_one_port(struct uart_driver
 	 * If this port is a console, then the spinlock is already
 	 * initialised.
 	 */
-	if (!uart_console(port))
+	if (!(uart_console(port) && (port->cons->flags & CON_ENABLED)))
 		spin_lock_init(&port->lock);
 
 	uart_configure_port(drv, state, port);
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/