From 570dfa7c55a76258b03a2d93f9db12dacc2ad3c6 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Tue, 19 Jan 2016 12:51:07 +0100 Subject: [PATCH] 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: Viresh Kumar Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman --- drivers/staging/greybus/connection.c | 19 ++++++++++++++++++- drivers/staging/greybus/connection.h | 7 ++++++- drivers/staging/greybus/operation.c | 7 +++++-- 3 files changed, 29 insertions(+), 4 deletions(-) diff --git a/drivers/staging/greybus/connection.c b/drivers/staging/greybus/connection.c index 56588f3..8ae099d 100644 --- a/drivers/staging/greybus/connection.c +++ b/drivers/staging/greybus/connection.c @@ -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; - connection->state = GB_CONNECTION_STATE_ENABLED; + 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 @@ err_svc_destroy: 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); diff --git a/drivers/staging/greybus/connection.h b/drivers/staging/greybus/connection.h index e7c6feb..ab2556d 100644 --- a/drivers/staging/greybus/connection.h +++ b/drivers/staging/greybus/connection.h @@ -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); diff --git a/drivers/staging/greybus/operation.c b/drivers/staging/greybus/operation.c index 4dc79cb..d6b3d1f 100644 --- a/drivers/staging/greybus/operation.c +++ b/drivers/staging/greybus/operation.c @@ -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; -- 2.7.4