From 238bbe98558bcd5ed9ab73ef03db82b57ab056ab Mon Sep 17 00:00:00 2001
From: Giulio Benetti <giulio.benetti@micronovasrl.com>
Date: Fri, 31 Aug 2018 15:18:22 +0200
Subject: [PATCH] sysdep1: check if RS485 is support before setting its
 parameters

Not every kernel supports RS485, so better check it before setting its
parameters.

Test if RS485 is supported by checking if these 3 macros are defined:
- SER_RS485_ENABLED
- TIOCGRS485
- TIOCSRS485
If they're not defined m_set485parms becomes a dummy function.

Signed-off-by: Giulio Benetti <giulio.benetti@micronovasrl.com>
---
 src/sysdep1.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/sysdep1.c b/src/sysdep1.c
index 798b006..b03b442 100644
--- a/src/sysdep1.c
+++ b/src/sysdep1.c
@@ -599,7 +599,7 @@ void m_set485parms(int fd, int en, int rts_on_snd, int rts_aft_snd,
                    int rx_dur_tx, int term_bus, char *del_rts_bef_snd,
                    char *del_rts_aft_snd)
 {
-#ifdef SER_RS485_ENABLED
+#if defined (SER_RS485_ENABLED) && defined (TIOCGRS485) && defined (TIOCSRS485)
   struct serial_rs485 rs485conf;
 
   if (ioctl(fd, TIOCGRS485, &rs485conf))
-- 
2.17.1