Display001GfA/patches/0005-GfA-empty-input-queue-on-CRC-error.patch

From d8d71642ad7b1209e2aa8d3fb227d37051076248 Mon Sep 17 00:00:00 2001
From: Reinhard Russinger <reinhard@russinger.at>
Date: Fri, 22 Jun 2018 10:41:45 +0200
Subject: [PATCH] GfA empty input queue on CRC error

---
 .../003-GfA-empty-input-queue-on-CRC-error.patch   | 39 ++++++++++++++++++++++
 1 file changed, 39 insertions(+)
 create mode 100644 package/libmodbus/003-GfA-empty-input-queue-on-CRC-error.patch

diff --git a/package/libmodbus/003-GfA-empty-input-queue-on-CRC-error.patch b/package/libmodbus/003-GfA-empty-input-queue-on-CRC-error.patch
new file mode 100644
index 0000000..79a7ae3
--- /dev/null
+++ b/package/libmodbus/003-GfA-empty-input-queue-on-CRC-error.patch
@@ -0,0 +1,39 @@
+diff '--exclude=.libs*' '--exclude=*.la' '--exclude=*.lo' '--exclude=Makefile*' -Naurp libmodbus-3.0.6/src/modbus-rtu.c b/src/modbus-rtu.c
+--- libmodbus-3.0.6/src/modbus-rtu.c	2018-06-22 10:34:55.987233891 +0200
++++ b/src/modbus-rtu.c	2018-06-18 19:47:12.682614777 +0200
+@@ -323,6 +323,35 @@ int _modbus_rtu_check_integrity(modbus_t
+     if (crc_calculated == crc_received) {
+         return msg_length;
+     } else {
++        modbus_rtu_t *ctx_rtu = ctx->backend_data;    
++        
++        if(ctx_rtu->echohw) {/* on active echomode empty receiver on crc error */
++            int rc;
++            fd_set rfds;
++            struct timeval tv;    
++        
++            /* Add a file descriptor to the set */
++            FD_ZERO(&rfds);
++            FD_SET(ctx->s, &rfds);
++            
++            if (ctx->debug) {
++                fprintf(stderr, "ERROR CRC received on ECHOHW empty input tv.tv_sec=%d tv.tv_usec=%d\n",
++                        (int)ctx->response_timeout.tv_sec,
++                        (int)ctx->response_timeout.tv_usec);
++                fflush(stderr);                    
++            }
++        
++            do {
++               unsigned char cc[256]; /* dummy buffer für cleaning input */
++           
++               tv.tv_sec = ctx->response_timeout.tv_sec;
++               tv.tv_usec = ctx->response_timeout.tv_usec;
++
++               rc = ctx->backend->select(ctx, &rfds, &tv, sizeof(cc));
++               if(rc > 0) ctx->backend->recv(ctx, msg + msg_length, rc);           
++               } while(rc > 0); /* read until transfer empty */
++            }
++               
+         if (ctx->debug) {
+             fprintf(stderr, "ERROR CRC received %0X != CRC calculated %0X\n",
+                     crc_received, crc_calculated);
-- 
2.7.4