diff --git a/src/arduino.c b/src/arduino.c
index 89b6e825..0a071b99 100644
--- a/src/arduino.c
+++ b/src/arduino.c
@@ -119,9 +119,9 @@ static int arduino_open(PROGRAMMER *pgm, const char *port) {
   union pinfo pinfo;
   pinfo.serialinfo.baud = pgm->baudrate? pgm->baudrate: 115200;
   pinfo.serialinfo.cflags = SERIAL_8N1;
-  if(serial_open(port, pinfo, &pgm->fd) == -1) {
-    return -1;
-  }
+  int rc;
+  if((rc = serial_open(port, pinfo, &pgm->fd)) < 0)
+    return rc;
 
   if(my.autoreset) {
     // This code assumes a negative-logic USB to TTL serial adapter
diff --git a/src/avr910.c b/src/avr910.c
index 67cac3f5..94d4c1b3 100644
--- a/src/avr910.c
+++ b/src/avr910.c
@@ -328,8 +328,9 @@ static int avr910_open(PROGRAMMER *pgm, const char *port) {
   pgm->port = port;
   pinfo.serialinfo.baud = pgm->baudrate? pgm->baudrate: 19200;
   pinfo.serialinfo.cflags = SERIAL_8N1;
-  if(serial_open(port, pinfo, &pgm->fd) < 0)
-    return -1;
+  int rc;
+  if((rc = serial_open(port, pinfo, &pgm->fd)) < 0)
+    return rc;
 
   (void) avr910_drain(pgm, 0);
 
diff --git a/src/buspirate.c b/src/buspirate.c
index 5a96a013..658c3b29 100644
--- a/src/buspirate.c
+++ b/src/buspirate.c
@@ -448,9 +448,9 @@ static int buspirate_open(PROGRAMMER *pgm, const char *port) {
   pinfo.serialinfo.baud = pgm->baudrate? pgm->baudrate: 115200;
   pinfo.serialinfo.cflags = SERIAL_8N1;
   pgm->port = port;
-  if(serial_open(port, pinfo, &pgm->fd) == -1) {
-    return -1;
-  }
+  int rc;
+  if((rc = serial_open(port, pinfo, &pgm->fd)) < 0)
+    return rc;
 
   // Drain any extraneous input
   serial_drain(&pgm->fd, 0);
diff --git a/src/butterfly.c b/src/butterfly.c
index 5c803659..16d80f86 100644
--- a/src/butterfly.c
+++ b/src/butterfly.c
@@ -329,8 +329,9 @@ static int butterfly_open(PROGRAMMER *pgm, const char *port) {
   union pinfo pinfo;
   pinfo.serialinfo.baud = pgm->baudrate? pgm->baudrate: 19200;
   pinfo.serialinfo.cflags = SERIAL_8N1;
-  if(serial_open(port, pinfo, &pgm->fd) == -1)
-    return -1;
+  int rc;
+  if((rc = serial_open(port, pinfo, &pgm->fd)) < 0)
+    return rc;
 
   if(my.autoreset) {
     // This code assumes a negative-logic USB to TTL serial adapter
diff --git a/src/jtag3.c b/src/jtag3.c
index 89443af3..f3560bde 100644
--- a/src/jtag3.c
+++ b/src/jtag3.c
@@ -1673,6 +1673,8 @@ int jtag3_open_common(PROGRAMMER *pgm, const char *port, int mode_switch) {
 
     pgm->port = port;
     rv = serial_open(port, pinfo, &pgm->fd);
+    if(rv == LIBAVRDUDE_EXIT_FAIL || rv == LIBAVRDUDE_EXIT_OK)
+      return rv;
   }
   if(rv < 0) {
 #endif                          // HAVE_LIBHIDAPI
@@ -1689,6 +1691,8 @@ int jtag3_open_common(PROGRAMMER *pgm, const char *port, int mode_switch) {
 
       pgm->port = port;
       rv = serial_open(port, pinfo, &pgm->fd);
+      if(rv == LIBAVRDUDE_EXIT_FAIL || rv == LIBAVRDUDE_EXIT_OK)
+        return rv;
     }
 #endif                          // HAVE_LIBUSB
 
@@ -1714,9 +1718,13 @@ int jtag3_open_common(PROGRAMMER *pgm, const char *port, int mode_switch) {
         int pic_mode = serial_open(port, pinfo, &pgm->fd);
 
         if(pic_mode < 0) {
+          if(pic_mode == LIBAVRDUDE_EXIT_FAIL || pic_mode == LIBAVRDUDE_EXIT_OK)
+            return pic_mode;
           // Retry with bootloader USB PID
           pinfo.usbinfo.pid = bl_pid;
           pic_mode = serial_open(port, pinfo, &pgm->fd);
+          if(pic_mode == LIBAVRDUDE_EXIT_FAIL || pic_mode == LIBAVRDUDE_EXIT_OK)
+            return pic_mode;
         }
         if(pic_mode >= 0) {
           const char *partsdesc_flag = partdesc? " -p ": "";
diff --git a/src/jtagmkI.c b/src/jtagmkI.c
index b4600d86..854abb4a 100644
--- a/src/jtagmkI.c
+++ b/src/jtagmkI.c
@@ -522,9 +522,9 @@ static int jtagmkI_open(PROGRAMMER *pgm, const char *port) {
     pinfo.serialinfo.baud = baudtab[i].baud;
     pinfo.serialinfo.cflags = SERIAL_8N1;
     pmsg_notice2("%s(): trying to sync at baud rate %ld:\n", __func__, pinfo.serialinfo.baud);
-    if(serial_open(port, pinfo, &pgm->fd) == -1) {
-      return -1;
-    }
+    int rc;
+    if((rc = serial_open(port, pinfo, &pgm->fd)) < 0)
+      return rc;
 
     // Drain any extraneous input
     jtagmkI_drain(pgm, 0);
diff --git a/src/jtagmkII.c b/src/jtagmkII.c
index 0d7f6be4..a7fcaeb6 100644
--- a/src/jtagmkII.c
+++ b/src/jtagmkII.c
@@ -1417,9 +1417,9 @@ static int jtagmkII_open(PROGRAMMER *pgm, const char *port) {
   }
 
   pgm->port = port;
-  if(serial_open(port, pinfo, &pgm->fd) == -1) {
-    return -1;
-  }
+  int rc;
+  if((rc = serial_open(port, pinfo, &pgm->fd)) < 0)
+    return rc;
 
   // Drain any extraneous input
   jtagmkII_drain(pgm, 0);
@@ -1467,9 +1467,9 @@ static int jtagmkII_open_dw(PROGRAMMER *pgm, const char *port) {
   }
 
   pgm->port = port;
-  if(serial_open(port, pinfo, &pgm->fd) == -1) {
-    return -1;
-  }
+  int rc;
+  if((rc = serial_open(port, pinfo, &pgm->fd)) < 0)
+    return rc;
 
   // Drain any extraneous input
   jtagmkII_drain(pgm, 0);
@@ -1517,9 +1517,9 @@ static int jtagmkII_open_pdi(PROGRAMMER *pgm, const char *port) {
   }
 
   pgm->port = port;
-  if(serial_open(port, pinfo, &pgm->fd) == -1) {
-    return -1;
-  }
+  int rc;
+  if((rc = serial_open(port, pinfo, &pgm->fd)) < 0)
+    return rc;
 
   // Drain any extraneous input
   jtagmkII_drain(pgm, 0);
@@ -1573,9 +1573,9 @@ static int jtagmkII_dragon_open(PROGRAMMER *pgm, const char *port) {
   }
 
   pgm->port = port;
-  if(serial_open(port, pinfo, &pgm->fd) == -1) {
-    return -1;
-  }
+  int rc;
+  if((rc = serial_open(port, pinfo, &pgm->fd)) < 0)
+    return rc;
 
   // Drain any extraneous input
   jtagmkII_drain(pgm, 0);
@@ -1623,9 +1623,9 @@ static int jtagmkII_dragon_open_dw(PROGRAMMER *pgm, const char *port) {
   }
 
   pgm->port = port;
-  if(serial_open(port, pinfo, &pgm->fd) == -1) {
-    return -1;
-  }
+  int rc;
+  if((rc = serial_open(port, pinfo, &pgm->fd)) < 0)
+    return rc;
 
   // Drain any extraneous input
   jtagmkII_drain(pgm, 0);
@@ -1650,11 +1650,7 @@ static int jtagmkII_dragon_open_pdi(PROGRAMMER *pgm, const char *port) {
   pinfo.serialinfo.baud = 19200;
   pinfo.serialinfo.cflags = SERIAL_8N1;
 
-  /*
-   * If the port name starts with "usb", divert the serial routines to the USB
-   * ones.  The serial_open() function for USB overrides the meaning of the
-   * "baud" parameter to be the USB device ID to search for.
-   */
+  // If the port name starts with "usb", divert the serial routines to the USB ones
   if(str_casestarts(port, "usb")) {
 
 #if defined(HAVE_LIBUSB)
@@ -1673,9 +1669,9 @@ static int jtagmkII_dragon_open_pdi(PROGRAMMER *pgm, const char *port) {
   }
 
   pgm->port = port;
-  if(serial_open(port, pinfo, &pgm->fd) == -1) {
-    return -1;
-  }
+  int rc;
+  if((rc = serial_open(port, pinfo, &pgm->fd)) < 0)
+    return rc;
 
   // Drain any extraneous input
   jtagmkII_drain(pgm, 0);
@@ -3255,9 +3251,9 @@ static int jtagmkII_open32(PROGRAMMER *pgm, const char *port) {
   }
 
   pgm->port = port;
-  if(serial_open(port, pinfo, &pgm->fd) == -1) {
-    return -1;
-  }
+  int rc;
+  if((rc = serial_open(port, pinfo, &pgm->fd)) < 0)
+    return rc;
 
   // Drain any extraneous input
   jtagmkII_drain(pgm, 0);
diff --git a/src/serialadapter.c b/src/serialadapter.c
index 07eedb87..c92a4b33 100644
--- a/src/serialadapter.c
+++ b/src/serialadapter.c
@@ -331,9 +331,10 @@ int touch_serialport(char **portp, int baudrate, int nwaits) {
 
   pinfo.serialinfo.baud = baudrate;
   pinfo.serialinfo.cflags = SERIAL_8N1;
-  if(serial_open(*portp, pinfo, &fd) == -1) {
+  int rc;
+  if((rc = serial_open(*portp, pinfo, &fd)) < 0) {
     pmsg_error("%s() failed to open port %s at %d baud\n", __func__, *portp, baudrate);
-    return -1;
+    return rc;
   }
   serial_set_dtr_rts(&fd, 1);
   usleep(100);
diff --git a/src/serprog.c b/src/serprog.c
index dfab68a3..d27cc886 100644
--- a/src/serprog.c
+++ b/src/serprog.c
@@ -169,8 +169,9 @@ static int serprog_open(PROGRAMMER *pgm, const char *port) {
   pgm->port = port;
   pinfo.serialinfo.baud = pgm->baudrate? pgm->baudrate: 115200;
   pinfo.serialinfo.cflags = SERIAL_8N1;
-  if(serial_open(port, pinfo, &pgm->fd) == -1)
-    return -1;
+  int rc;
+  if((rc = serial_open(port, pinfo, &pgm->fd)) < 0)
+    return rc;
 
   unsigned char buf[32];
 
diff --git a/src/stk500.c b/src/stk500.c
index 6e00e753..a8100213 100644
--- a/src/stk500.c
+++ b/src/stk500.c
@@ -854,9 +854,9 @@ static int stk500_open(PROGRAMMER *pgm, const char *port) {
   pgm->port = port;
   pinfo.serialinfo.baud = pgm->baudrate? pgm->baudrate: 115200;
   pinfo.serialinfo.cflags = SERIAL_8N1;
-  if(serial_open(port, pinfo, &pgm->fd) == -1) {
-    return -1;
-  }
+  int rc;
+  if((rc = serial_open(port, pinfo, &pgm->fd)) < 0)
+    return rc;
 
   // Drain any extraneous input
   stk500_drain(pgm, 0);
diff --git a/src/stk500v2.c b/src/stk500v2.c
index 84feea26..c4a8f1c6 100644
--- a/src/stk500v2.c
+++ b/src/stk500v2.c
@@ -1365,7 +1365,7 @@ static int stk500v2_jtag3_initialize(const PROGRAMMER *pgm, const AVRPART *p) {
     if(my.vtarg_switch_get) {
       pmsg_info("Vtarg switch setting read as %u: target power is switched %s\n",
         my.vtarg_switch_data[0], my.vtarg_switch_data[0]? "on": "off");
-    } 
+    }
     // Write Vtarg switch value
     if(my.vtarg_switch_set) {
       if(jtag3_setparm(pgmcp, SCOPE_EDBG, EDBG_CTXT_CONTROL,
@@ -1504,7 +1504,7 @@ static int stk500hv_initialize(const PROGRAMMER *pgm, const AVRPART *p, enum hvm
           my.varef_channel, (varef_read/100.0));
       }
       // STK600: Write target voltage value for channel n
-      if(my.varef_set) {                  
+      if(my.varef_set) {
         msg_info("Changing analog reference channel %d voltage from %.2f V to %.2f V\n",
           my.varef_channel, (varef_read/100.0), my.varef_data);
         if(pgm->set_varef(pgm, my.varef_channel, my.varef_data) < 0)
@@ -2148,9 +2148,9 @@ static int stk500v2_open(PROGRAMMER *pgm, const char *port) {
   }
 
   pgm->port = port;
-  if(serial_open(port, pinfo, &pgm->fd) == -1) {
-    return -1;
-  }
+  int rc;
+  if((rc = serial_open(port, pinfo, &pgm->fd)) < 0)
+    return rc;
 
   // Make USB serial number and USB product name available to programmer
   if(serdev) {
@@ -2216,9 +2216,9 @@ static int stk600_open(PROGRAMMER *pgm, const char *port) {
   }
 
   pgm->port = port;
-  if(serial_open(port, pinfo, &pgm->fd) == -1) {
-    return -1;
-  }
+  int rc;
+  if((rc = serial_open(port, pinfo, &pgm->fd)) < 0)
+    return rc;
 
   // Drain any extraneous input, synchronise and drain again
   if(stk500v2_drain(pgm, 0) < 0 || stk500v2_getsync(pgm) < 0 || stk500v2_drain(pgm, 0) < 0)
@@ -3927,9 +3927,9 @@ static int stk500v2_jtagmkII_open(PROGRAMMER *pgm, const char *port) {
   }
 
   pgm->port = port;
-  if(serial_open(port, pinfo, &pgm->fd) == -1) {
-    return -1;
-  }
+  int rc;
+  if((rc = serial_open(port, pinfo, &pgm->fd)) < 0)
+    return rc;
 
   // Drain any extraneous input
   stk500v2_drain(pgm, 0);
@@ -4025,9 +4025,9 @@ static int stk500v2_dragon_isp_open(PROGRAMMER *pgm, const char *port) {
   }
 
   pgm->port = port;
-  if(serial_open(port, pinfo, &pgm->fd) == -1) {
-    return -1;
-  }
+  int rc;
+  if((rc = serial_open(port, pinfo, &pgm->fd)) < 0)
+    return rc;
 
   // Drain any extraneous input
   stk500v2_drain(pgm, 0);
@@ -4098,9 +4098,9 @@ static int stk500v2_dragon_hv_open(PROGRAMMER *pgm, const char *port) {
   }
 
   pgm->port = port;
-  if(serial_open(port, pinfo, &pgm->fd) == -1) {
-    return -1;
-  }
+  int rc;
+  if((rc = serial_open(port, pinfo, &pgm->fd)) < 0)
+    return rc;
 
   // Drain any extraneous input
   stk500v2_drain(pgm, 0);
diff --git a/src/updi_link.c b/src/updi_link.c
index 5666a6b9..89eff004 100644
--- a/src/updi_link.c
+++ b/src/updi_link.c
@@ -57,10 +57,10 @@ static int updi_physical_open(PROGRAMMER *pgm, int baudrate, unsigned long cflag
 
   pmsg_debug("opening serial port ...\n");
 
-  if(serial_open(pgm->port, pinfo, &pgm->fd) == -1) {
-
+  int rc;
+  if((rc = serial_open(pgm->port, pinfo, &pgm->fd)) < 0) {
     pmsg_debug("serial port open failed!\n");
-    return -1;
+    return rc;
   }
 
   // Drain any extraneous input
diff --git a/src/urclock.c b/src/urclock.c
index 29dcbb94..7423320e 100644
--- a/src/urclock.c
+++ b/src/urclock.c
@@ -2249,8 +2249,9 @@ static int urclock_open(PROGRAMMER *pgm, const char *port) {
   pinfo.serialinfo.cflags = SERIAL_8N1;
 
   pmsg_debug("%s(\"%s\")\n", __func__, port);
-  if(serial_open(port, pinfo, &pgm->fd) == -1)
-    return -1;
+  int rc;
+  if((rc = serial_open(port, pinfo, &pgm->fd)) < 0)
+    return rc;
 
   if(!ur.noautoreset) {
     // This code assumes a negative-logic USB to TTL serial adapter
diff --git a/src/wiring.c b/src/wiring.c
index 80ab3f40..aee1cd05 100644
--- a/src/wiring.c
+++ b/src/wiring.c
@@ -144,7 +144,9 @@ static int wiring_open(PROGRAMMER *pgm, const char *port) {
   pgm->port = port;
   pinfo.serialinfo.baud = pgm->baudrate? pgm->baudrate: 115200;
   pinfo.serialinfo.cflags = SERIAL_8N1;
-  serial_open(port, pinfo, &pgm->fd);
+  int rc;
+  if((rc = serial_open(port, pinfo, &pgm->fd)) < 0)
+    return rc;
 
   // If we have a snoozetime, then we wait and do NOT toggle DTR/RTS
   if(mywiring.snoozetime > 0) {
diff --git a/src/xbee.c b/src/xbee.c
index e8b0f69a..06c85921 100644
--- a/src/xbee.c
+++ b/src/xbee.c
@@ -1438,9 +1438,9 @@ static int xbee_open(PROGRAMMER *pgm, const char *port) {
   serdev->set_dtr_rts = xbeedev_set_dtr_rts;
   serdev->flags = SERDEV_FL_NONE;
 
-  if(serial_open(port, pinfo, &pgm->fd) == -1) {
-    return -1;
-  }
+  int rc;
+  if((rc = serial_open(port, pinfo, &pgm->fd)) < 0)
+    return rc;
 
   xbeedev_setresetpin(&pgm->fd, my.xbeeResetPin);