greybus: send operation response messages

Define a helper function gb_operation_response_alloc() and use it
to allocate the response buffer for outgoing operations in
gb_operation_create_common(.

Use it also in  gb_operation_response_send() if the caller has not
allocated a response buffer.

Once a response buffer is allocated, fill in its result code and
send it.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/staging/greybus/operation.h b/drivers/staging/greybus/operation.h
index adaec7c43ea9..c60decb40539 100644
--- a/drivers/staging/greybus/operation.h
+++ b/drivers/staging/greybus/operation.h
@@ -98,6 +98,9 @@ static inline void gb_operation_destroy(struct gb_operation *operation)
 	gb_operation_put(operation);
 }
 
+bool gb_operation_response_alloc(struct gb_operation *operation,
+					size_t response_size);
+
 int gb_operation_request_send(struct gb_operation *operation,
 				gb_operation_callback callback);
 int gb_operation_response_send(struct gb_operation *operation, int errno);