ols: Fix a serial port related issue on FreeBSD.

Add sp_drain() to ensure bytes have actually been transmitted
over the wire.

This fixes bug #414.

src/hardware/openbench-logic-sniffer/protocol.c

@@ -33,6 +33,9 @@ SR_PRIV int send_shortcommand(struct sr_serial_dev_inst *serial,
 	if (serial_write_blocking(serial, buf, 1, serial_timeout(serial, 1)) != 1)
 		return SR_ERR;
 
+	if (serial_drain(serial) != 0)
+		return SR_ERR;
+
 	return SR_OK;
 }
 
@@ -51,6 +54,9 @@ SR_PRIV int send_longcommand(struct sr_serial_dev_inst *serial,
 	if (serial_write_blocking(serial, buf, 5, serial_timeout(serial, 1)) != 5)
 		return SR_ERR;
 
+	if (serial_drain(serial) != 0)
+		return SR_ERR;
+
 	return SR_OK;
 }
 

src/libsigrok-internal.h

@@ -631,6 +631,7 @@ typedef gboolean (*packet_valid_callback)(const uint8_t *buf);
 SR_PRIV int serial_open(struct sr_serial_dev_inst *serial, int flags);
 SR_PRIV int serial_close(struct sr_serial_dev_inst *serial);
 SR_PRIV int serial_flush(struct sr_serial_dev_inst *serial);
+SR_PRIV int serial_drain(struct sr_serial_dev_inst *serial);
 SR_PRIV int serial_write_blocking(struct sr_serial_dev_inst *serial,
 		const void *buf, size_t count, unsigned int timeout_ms);
 SR_PRIV int serial_write_nonblocking(struct sr_serial_dev_inst *serial,

src/serial.c

@@ -4,6 +4,7 @@
  * Copyright (C) 2010-2012 Bert Vermeulen <bert@biot.com>
  * Copyright (C) 2010-2012 Uwe Hermann <uwe@hermann-uwe.de>
  * Copyright (C) 2012 Alexandru Gagniuc <mr.nuke.me@gmail.com>
+ * Copyright (C) 2014 Uffe Jakobsen <uffe@uffe.org>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -169,6 +170,44 @@ SR_PRIV int serial_flush(struct sr_serial_dev_inst *serial)
 	return SR_OK;
 }
 
+/**
+ * Drain serial port buffers.
+ *
+ * @param serial Previously initialized serial port structure.
+ *
+ * @retval SR_OK Success.
+ * @retval SR_ERR Failure.
+ */
+SR_PRIV int serial_drain(struct sr_serial_dev_inst *serial)
+{
+	int ret;
+	char *error;
+
+	if (!serial) {
+		sr_dbg("Invalid serial port.");
+		return SR_ERR;
+	}
+
+	if (!serial->data) {
+		sr_dbg("Cannot drain unopened serial port %s.", serial->port);
+		return SR_ERR;
+	}
+
+	sr_spew("Draining serial port %s.", serial->port);
+
+	ret = sp_drain(serial->data);
+
+	if (ret == SP_ERR_FAIL) {
+		error = sp_last_error_message();
+		sr_err("Error draining port (%d): %s.",
+			sp_last_error_code(), error);
+		sp_free_error_message(error);
+		return SR_ERR;
+	}
+
+	return SR_OK;
+}
+
 static int _serial_write(struct sr_serial_dev_inst *serial,
 		const void *buf, size_t count, int nonblocking, unsigned int timeout_ms)
 {