[PATCH v5 3/9] greybus: operation: arm request timeout before sending

[Ayush Singh]

The host driver can complete a request before add_timer is called. The
main case for this is softsvc, although, depending on which transport
is used, there is a possibility that response arrives much faster than
expected.

By populating timer earilier, we prevent the starting a timer on
already completed request (which would then leak an active timer on cleanup).

Signed-off-by: Ayush Singh <ayush@xxxxxxxxxxxxxxx>
---
 drivers/greybus/operation.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/greybus/operation.c b/drivers/greybus/operation.c
index a63bc2eb164e..2d37acedf36f 100644
--- a/drivers/greybus/operation.c
+++ b/drivers/greybus/operation.c
@@ -782,20 +782,25 @@ int gb_operation_request_send(struct gb_operation *operation,
 		return 0;
 	}
 
+	/*
+	 * Arm the timeout before sending: the response can arrive, and the
+	 * operation complete, before the host driver returns.
+	 */
+	if (timeout) {
+		operation->timer.expires = jiffies + msecs_to_jiffies(timeout);
+		add_timer(&operation->timer);
+	}
+
 	ret = gb_message_send(operation->request, gfp);
 	gb_operation_put_active(operation);
 	gb_operation_put(operation);
 	if (ret)
 		goto err_put_active;
 
-	if (timeout) {
-		operation->timer.expires = jiffies + msecs_to_jiffies(timeout);
-		add_timer(&operation->timer);
-	}
-
 	return 0;
 
 err_put_active:
+	timer_delete_sync(&operation->timer);
 	gb_operation_put_active(operation);
 err_put:
 	gb_operation_put(operation);

-- 
2.56.0