Commit cad09a8f authored by Johan Hovold's avatar Johan Hovold Committed by Greg Kroah-Hartman
Browse files

greybus: connection: add connection-state locking 



Add locking, and the implied barriers, to connection-state updates.

This will be used to fix a number of races in the operations and
connection-tear-down implementations.

Signed-off-by: default avatarJohan Hovold <johan@hovoldconsulting.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@google.com>
parent 886c6069

drivers/staging/greybus/connection.c

+20 −4
Original line number Diff line number Diff line
@@ -65,8 +65,13 @@ static ssize_t state_show(struct device *dev, struct device_attribute *attr, 
			  char *buf)

{

	struct gb_connection *connection = to_gb_connection(dev);

	enum gb_connection_state state;



	return sprintf(buf, "%d\n", connection->state);

	spin_lock_irq(&connection->lock);

	state = connection->state;

	spin_unlock_irq(&connection->lock);



	return sprintf(buf, "%d\n", state);

}

static DEVICE_ATTR_RO(state);
@@ -204,6 +209,7 @@ struct gb_connection *gb_connection_create(struct gb_bundle *bundle, 
	spin_unlock_irq(&gb_connections_lock);



	atomic_set(&connection->op_cycle, 0);

	spin_lock_init(&connection->lock);

	INIT_LIST_HEAD(&connection->operations);



	/* XXX Will have to establish connections to get version */
@@ -274,10 +280,16 @@ int gb_connection_init(struct gb_connection *connection) 
	}



	/* Need to enable the connection to initialize it */

	spin_lock_irq(&connection->lock);

	connection->state = GB_CONNECTION_STATE_ENABLED;

	spin_unlock_irq(&connection->lock);



	ret = connection->protocol->connection_init(connection);

	if (ret)

	if (ret) {

		spin_lock_irq(&connection->lock);

		connection->state = GB_CONNECTION_STATE_ERROR;

		spin_unlock_irq(&connection->lock);

	}



	return ret;

}
@@ -291,10 +303,14 @@ void gb_connection_exit(struct gb_connection *connection) 
		return;

	}



	if (connection->state != GB_CONNECTION_STATE_ENABLED)

	spin_lock_irq(&connection->lock);

	if (connection->state != GB_CONNECTION_STATE_ENABLED) {

		spin_unlock_irq(&connection->lock);

		return;



	}

	connection->state = GB_CONNECTION_STATE_DESTROYING;

	spin_unlock_irq(&connection->lock);



	connection->protocol->connection_exit(connection);



	/*

drivers/staging/greybus/connection.h

+1 −0
Original line number Diff line number Diff line
@@ -35,6 +35,7 @@ struct gb_connection { 
	u8				major;

	u8				minor;



	spinlock_t			lock;

	enum gb_connection_state	state;



	atomic_t			op_cycle;