serialqueue: Message receive_time must be taken after read()

The est_clock calculation code requires timestamps on status messages
to never be prior to the reception of the message.  The eventtime of
handle_message() is taken before the read() and there is a small
possibility that it could be inaccurate enough to corrupt the
est_clock calculation.  Take a new timestamp when storing receive_time
to prevent this.  This fix prevents some firmware "Move queue empty"
shutdowns.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

1 files changed, 1 insertions, 1 deletions

diff --git a/klippy/serialqueue.c b/klippy/serialqueue.c
index 4c18c971..cb24d523 100644
--- a/klippy/serialqueue.c
+++ b/klippy/serialqueue.c
@@ -496,7 +496,7 @@ handle_message(struct serialqueue *sq, double eventtime, int len)
         // Add message to receive queue
         struct queue_message *qm = message_fill(sq->input_buf, len);
         qm->sent_time = sq->last_receive_sent_time;
-        qm->receive_time = eventtime;
+        qm->receive_time = get_monotonic(); // must be time post read()
         list_add_tail(&qm->node, &sq->receive_queue);
         check_wake_receive(sq);
     }