From beb6b7fede005ae351619b30a8940a04e797b9b2 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Tue, 19 Jan 2016 12:51:08 +0100 Subject: [PATCH] greybus: connection: add helper to disable incoming operations Add helper to disable and flush incoming operations. This is intended to be used by core to flush any incoming requests before calling driver disconnect, but could potentially later be exported for driver use as well. Note that we currently flush all incoming operation and allow the request handlers to run, but cancel any responses sent. This may need to be refined later. Reviewed-by: Viresh Kumar Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman --- drivers/staging/greybus/connection.c | 54 ++++++++++++++++++++++++++++++++++++ drivers/staging/greybus/connection.h | 1 + 2 files changed, 55 insertions(+) diff --git a/drivers/staging/greybus/connection.c b/drivers/staging/greybus/connection.c index 8ae099d..c3207c8 100644 --- a/drivers/staging/greybus/connection.c +++ b/drivers/staging/greybus/connection.c @@ -386,6 +386,42 @@ static void gb_connection_cancel_operations(struct gb_connection *connection, } } +/* + * Cancel all active incoming operations on a connection. + * + * Locking: Called with connection lock held and state set to ENABLED_TX. + */ +static void +gb_connection_flush_incoming_operations(struct gb_connection *connection, + int errno) +{ + struct gb_operation *operation; + bool incoming; + + while (!list_empty(&connection->operations)) { + incoming = false; + list_for_each_entry(operation, &connection->operations, + links) { + if (gb_operation_is_incoming(operation)) { + gb_operation_get(operation); + incoming = true; + break; + } + } + + if (!incoming) + break; + + spin_unlock_irq(&connection->lock); + + /* FIXME: flush, not cancel? */ + gb_operation_cancel_incoming(operation, errno); + gb_operation_put(operation); + + spin_lock_irq(&connection->lock); + } +} + int gb_connection_enable(struct gb_connection *connection, gb_request_handler_t handler) { @@ -450,6 +486,24 @@ err_unlock: } EXPORT_SYMBOL_GPL(gb_connection_enable); +void gb_connection_disable_rx(struct gb_connection *connection) +{ + mutex_lock(&connection->mutex); + + spin_lock_irq(&connection->lock); + if (connection->state != GB_CONNECTION_STATE_ENABLED) { + spin_unlock_irq(&connection->lock); + goto out_unlock; + } + connection->state = GB_CONNECTION_STATE_ENABLED_TX; + gb_connection_flush_incoming_operations(connection, -ESHUTDOWN); + connection->handler = NULL; + spin_unlock_irq(&connection->lock); + +out_unlock: + mutex_unlock(&connection->mutex); +} + void gb_connection_disable(struct gb_connection *connection) { mutex_lock(&connection->mutex); diff --git a/drivers/staging/greybus/connection.h b/drivers/staging/greybus/connection.h index ab2556d..8813f54 100644 --- a/drivers/staging/greybus/connection.h +++ b/drivers/staging/greybus/connection.h @@ -75,6 +75,7 @@ static inline int gb_connection_enable_tx(struct gb_connection *connection) { return gb_connection_enable(connection, NULL); } +void gb_connection_disable_rx(struct gb_connection *connection); void gb_connection_disable(struct gb_connection *connection); int gb_connection_legacy_init(struct gb_connection *connection); -- 2.7.4