b200: Make sure no GPS settings are applied when no gpsdo present.

This changes the exception message thrown when gpsdo is selected as a
clock source, but does not change the exception. Note that before,
during its first run, the B2x0 would happily accept gpsdo as a clock
source even when none was present.

1 files changed, 4 insertions, 1 deletions

diff --git a/host/lib/usrp/b200/b200_impl.cpp b/host/lib/usrp/b200/b200_impl.cpp
index 33f0850eb..9bd2799c2 100644
--- a/host/lib/usrp/b200/b200_impl.cpp
+++ b/host/lib/usrp/b200/b200_impl.cpp
@@ -1041,8 +1041,11 @@ void b200_impl::update_clock_source(const std::string &source)
         }
         _adf4001_iface->set_lock_to_ext_ref(true);
     }
-    else if (_gps and source == "gpsdo")
+    else if (source == "gpsdo")
     {
+        if (not _gps or not _gps->gps_detected()) {
+            throw uhd::key_error("update_clock_source: gpsdo selected, but no gpsdo detected!");
+        }
         if (_gpio_state.ref_sel != 1)
         {
             _gpio_state.ref_sel = 1;