Prevent TIOCMIWAIT from beinf sent to non-serial devices.

All regression tests pass.

1 files changed, 11 insertions, 9 deletions

diff --git a/gpsd.c b/gpsd.c
index fb3351e6..1f89d1b8 100644
--- a/gpsd.c
+++ b/gpsd.c
@@ -708,15 +708,17 @@ static bool open_device( /*@null@*/struct gps_device_t *device)
     }
 
 #ifdef NTPSHM_ENABLE
-    /*
-     * Now is the right time to grab the shared memory segment(s)
-     * to communicate the navigation message derived and (possibly)
-     * 1PPS derived time data to ntpd/chrony.
-     */
-    ntpshm_link_activate(device);
-    gpsd_report(&context.errout, LOG_INF, 
-		"NTPD ntpshm_link_activate: %d\n",
-		device->shm_clock != NULL);
+    if (device->sourcetype == source_rs232 || device->sourcetype == source_usb) {
+	/*
+	 * Now is the right time to grab the shared memory segment(s)
+	 * to communicate the navigation message derived and (possibly)
+	 * 1PPS derived time data to ntpd/chrony.
+	 */
+	ntpshm_link_activate(device);
+	gpsd_report(&context.errout, LOG_INF, 
+		    "NTPD ntpshm_link_activate: %d\n",
+		    device->shm_clock != NULL);
+    }
 #endif /* NTPSHM_ENABLE */
 
     gpsd_report(&context.errout, LOG_INF,