greybus: loopback: add response len to loopback protocol

This patch adds a len field to the loopback protocol.
This field is validated in gb_loopback_transfer() and stuffed in
gb_loopback_request_recv().

Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Reviewed-by: Patrick Titiano <ptitiano@baylibre.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

diff --git a/drivers/staging/greybus/greybus_protocols.h b/drivers/staging/greybus/greybus_protocols.h
index 77a7c49..76fea9a 100644 (file)
--- a/drivers/staging/greybus/greybus_protocols.h
+++ b/drivers/staging/greybus/greybus_protocols.h
@@ -917,6 +917,7 @@ struct gb_loopback_transfer_request {
 } __packed;
 
 struct gb_loopback_transfer_response {
+       __le32  len;
        __u8    data[0];
 } __packed;
 

diff --git a/drivers/staging/greybus/loopback.c b/drivers/staging/greybus/loopback.c
index a9b901f..ba65457 100644 (file)
--- a/drivers/staging/greybus/loopback.c
+++ b/drivers/staging/greybus/loopback.c
@@ -524,6 +524,7 @@ static int gb_loopback_request_recv(u8 type, struct gb_operation *operation)
                                return -ENOMEM;
                        }
                        response = operation->response->payload;
+                       response->len = cpu_to_le32(len);
                        memcpy(response->data, request->data, len);
                }
                return 0;