From: James Churchill <redacted>
Date: Sun, 18 Feb 2018 06:54:01 +0000 (+1000)
Subject: modbus: Return explicit SR_ERR values as required by modbus.c
X-Git-Url: https://sigrok.org/gitaction?a=commitdiff_plain;h=7b50a9b86987845bc596bfa226c69313afab6b8b;p=libsigrok.git

modbus: Return explicit SR_ERR values as required by modbus.c

The Modbus RTU implementation was inappropriately returning lengths
from the serial functions when the calling functions expect only an
sr_error_code value.
---

diff --git a/src/modbus/modbus_serial_rtu.c b/src/modbus/modbus_serial_rtu.c
index 4b15d241..065c25f6 100644
--- a/src/modbus/modbus_serial_rtu.c
+++ b/src/modbus/modbus_serial_rtu.c
@@ -111,18 +111,18 @@ static int modbus_serial_rtu_send(void *priv,
 
 	result = serial_write_blocking(serial, &slave_addr, sizeof(slave_addr), 0);
 	if (result < 0)
-		return result;
+		return SR_ERR;
 
 	result = serial_write_blocking(serial, buffer, buffer_size, 0);
 	if (result < 0)
-		return result;
+		return SR_ERR;
 
 	crc = modbus_serial_rtu_crc(0xFFFF, &slave_addr, sizeof(slave_addr));
 	crc = modbus_serial_rtu_crc(crc, buffer, buffer_size);
 
 	result = serial_write_blocking(serial, &crc, sizeof(crc), 0);
 	if (result < 0)
-		return result;
+		return SR_ERR;
 
 	return SR_OK;
 }
@@ -135,11 +135,11 @@ static int modbus_serial_rtu_read_begin(void *priv, uint8_t *function_code)
 
 	ret = serial_read_blocking(modbus->serial, &slave_addr, 1, 500);
 	if (ret != 1 || slave_addr != modbus->slave_addr)
-		return ret;
+		return SR_ERR;
 
 	ret = serial_read_blocking(modbus->serial, function_code, 1, 100);
 	if (ret != 1)
-		return ret;
+		return SR_ERR;
 
 	modbus->crc = modbus_serial_rtu_crc(0xFFFF, &slave_addr, sizeof(slave_addr));
 	modbus->crc = modbus_serial_rtu_crc(modbus->crc, function_code, 1);
@@ -167,7 +167,7 @@ static int modbus_serial_rtu_read_end(void *priv)
 
 	ret = serial_read_blocking(modbus->serial, &crc, sizeof(crc), 100);
 	if (ret != 2)
-		return ret;
+		return SR_ERR;
 
 	if (crc != modbus->crc) {
 		sr_err("CRC error (0x%04X vs 0x%04X).", crc, modbus->crc);