Commit 570dfa7c authored by Johan Hovold's avatar Johan Hovold Committed by Greg Kroah-Hartman
Browse files

greybus: connection: add unidirectional enabled state 



Add a new connection state ENABLED_TX in which only outgoing operations
are allowed.

This allows drivers to query the device during probe before allocating
their state containers without having to worry about racing incoming
requests.

Reviewed-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: default avatarJohan Hovold <johan@hovoldconsulting.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@google.com>
parent 23268785

drivers/staging/greybus/connection.c

+18 −1
Original line number Diff line number Diff line
@@ -396,6 +396,18 @@ int gb_connection_enable(struct gb_connection *connection, 
	if (connection->state == GB_CONNECTION_STATE_ENABLED)

		goto out_unlock;



	if (connection->state == GB_CONNECTION_STATE_ENABLED_TX) {

		if (!handler)

			goto out_unlock;



		spin_lock_irq(&connection->lock);

		connection->handler = handler;

		connection->state = GB_CONNECTION_STATE_ENABLED;

		spin_unlock_irq(&connection->lock);



		goto out_unlock;

	}



	ret = gb_connection_hd_cport_enable(connection);

	if (ret)

		goto err_unlock;
@@ -406,7 +418,10 @@ int gb_connection_enable(struct gb_connection *connection, 


	spin_lock_irq(&connection->lock);

	connection->handler = handler;

	if (handler)

		connection->state = GB_CONNECTION_STATE_ENABLED;

	else

		connection->state = GB_CONNECTION_STATE_ENABLED_TX;

	spin_unlock_irq(&connection->lock);



	ret = gb_connection_control_connected(connection);
@@ -422,6 +437,7 @@ int gb_connection_enable(struct gb_connection *connection, 
	spin_lock_irq(&connection->lock);

	connection->state = GB_CONNECTION_STATE_DISABLED;

	gb_connection_cancel_operations(connection, -ESHUTDOWN);

	connection->handler = NULL;

	spin_unlock_irq(&connection->lock);



	gb_connection_svc_connection_destroy(connection);
@@ -446,6 +462,7 @@ void gb_connection_disable(struct gb_connection *connection) 
	spin_lock_irq(&connection->lock);

	connection->state = GB_CONNECTION_STATE_DISABLED;

	gb_connection_cancel_operations(connection, -ESHUTDOWN);

	connection->handler = NULL;

	spin_unlock_irq(&connection->lock);



	gb_connection_svc_connection_destroy(connection);

drivers/staging/greybus/connection.h

+6 −1
Original line number Diff line number Diff line
@@ -16,7 +16,8 @@ 
enum gb_connection_state {

	GB_CONNECTION_STATE_INVALID	= 0,

	GB_CONNECTION_STATE_DISABLED	= 1,

	GB_CONNECTION_STATE_ENABLED	= 2,

	GB_CONNECTION_STATE_ENABLED_TX	= 2,

	GB_CONNECTION_STATE_ENABLED	= 3,

};



struct gb_operation;
@@ -70,6 +71,10 @@ static inline bool gb_connection_is_static(struct gb_connection *connection) 


int gb_connection_enable(struct gb_connection *connection,

					gb_request_handler_t handler);

static inline int gb_connection_enable_tx(struct gb_connection *connection)

{

	return gb_connection_enable(connection, NULL);

}

void gb_connection_disable(struct gb_connection *connection);



int gb_connection_legacy_init(struct gb_connection *connection);

drivers/staging/greybus/operation.c

+5 −2
Original line number Diff line number Diff line
@@ -47,7 +47,9 @@ static int gb_operation_get_active(struct gb_operation *operation) 


	spin_lock_irqsave(&connection->lock, flags);



	if (connection->state != GB_CONNECTION_STATE_ENABLED) {

	if (connection->state != GB_CONNECTION_STATE_ENABLED &&

			connection->state != GB_CONNECTION_STATE_ENABLED_TX &&

			!gb_operation_is_incoming(operation)) {

		spin_unlock_irqrestore(&connection->lock, flags);

		return -ENOTCONN;

	}
@@ -906,7 +908,8 @@ void gb_connection_recv(struct gb_connection *connection, 
	size_t msg_size;

	u16 operation_id;



	if (connection->state != GB_CONNECTION_STATE_ENABLED) {

	if (connection->state != GB_CONNECTION_STATE_ENABLED &&

		connection->state != GB_CONNECTION_STATE_ENABLED_TX) {

		dev_warn(dev, "%s: dropping %zu received bytes\n",

				connection->name, size);

		return;