rdtech-tc: avoid too eager request retransmission

[libsigrok.git] / src / hardware / rdtech-tc / protocol.c

diff --git a/src/hardware/rdtech-tc/protocol.c b/src/hardware/rdtech-tc/protocol.c
index bef28a932a4418a368c7f7fa21f73da28c7ed50d..3dff0d6a8271e358b411d66220432386d44f27c2 100644 (file)
--- a/src/hardware/rdtech-tc/protocol.c
+++ b/src/hardware/rdtech-tc/protocol.c
@@ -202,10 +202,17 @@ SR_PRIV int rdtech_tc_poll(const struct sr_dev_inst *sdi, gboolean force)
 
        /*
         * Don't send the request while receive data is being accumulated.
+        * Defer request transmission when a previous request has not yet
+        * seen any response data at all (more probable to happen shortly
+        * after connecting to the peripheral).
         */
        devc = sdi->priv;
-       if (!force && devc->rdlen)
-               return SR_OK;
+       if (!force) {
+               if (devc->rdlen)
+                       return SR_OK;
+               if (!devc->rx_after_tx)
+                       return SR_OK;
+       }
 
        /*
         * Send the request when the transmit interval was reached. Or
@@ -228,6 +235,7 @@ SR_PRIV int rdtech_tc_poll(const struct sr_dev_inst *sdi, gboolean force)
                return SR_ERR;
        }
        devc->cmd_sent_at = now;
+       devc->rx_after_tx = 0;
 
        return SR_OK;
 }
@@ -291,6 +299,7 @@ static int recv_poll_data(struct sr_dev_inst *sdi, struct sr_serial_dev_inst *se
                if (len == 0)
                        return SR_OK;
                devc->rdlen += len;
+               devc->rx_after_tx += len;
        }
 
        /*