3 files changed, 22 insertions, 14 deletions

diff --git a/host/lib/usrp/misc_utils.cpp b/host/lib/usrp/misc_utils.cpp
index da22d79f1..930314fc2 100644
--- a/host/lib/usrp/misc_utils.cpp
+++ b/host/lib/usrp/misc_utils.cpp
@@ -127,14 +127,17 @@ static void verify_xx_subdev_spec(
     wax::obj mboard,
     std::string xx_type
 ){
+    prop_names_t dboard_names = mboard[dboard_names_prop].as<prop_names_t>();
+    UHD_ASSERT_THROW(dboard_names.size() > 0); //well i hope there is a dboard
+
     //the subdevice specification is empty: handle automatic
     if (subdev_spec.empty()){
-        BOOST_FOREACH(const std::string &db_name, mboard[dboard_names_prop].as<prop_names_t>()){
+        BOOST_FOREACH(const std::string &db_name, dboard_names){
             wax::obj dboard = mboard[named_prop_t(dboard_prop, db_name)];
 
             //if the dboard slot is populated, take the first subdevice
             if (dboard[DBOARD_PROP_DBOARD_ID].as<dboard_id_t>() != dboard_id_t::none()){
-                std::string sd_name = dboard[DBOARD_PROP_SUBDEV_NAMES].as<prop_names_t>().at(0);
+                std::string sd_name = dboard[DBOARD_PROP_SUBDEV_NAMES].as<prop_names_t>().front();
                 subdev_spec.push_back(subdev_spec_pair_t(db_name, sd_name));
                 break;
             }
@@ -142,16 +145,23 @@ static void verify_xx_subdev_spec(
 
         //didnt find any populated dboards: add the first subdevice
         if (subdev_spec.empty()){
-            std::string db_name = mboard[dboard_names_prop].as<prop_names_t>().at(0);
+            std::string db_name = dboard_names.front();
             wax::obj dboard = mboard[named_prop_t(dboard_prop, db_name)];
-            std::string sd_name = dboard[DBOARD_PROP_SUBDEV_NAMES].as<prop_names_t>().at(0);
+            std::string sd_name = dboard[DBOARD_PROP_SUBDEV_NAMES].as<prop_names_t>().front();
             subdev_spec.push_back(subdev_spec_pair_t(db_name, sd_name));
         }
     }
 
     //sanity check that the dboard/subdevice names exist for this mboard
     BOOST_FOREACH(const subdev_spec_pair_t &pair, subdev_spec){
-        uhd::assert_has(mboard[dboard_names_prop].as<prop_names_t>(),        pair.db_name, xx_type + " dboard name");
+        //empty db name means select dboard automatically
+        if (pair.db_name.empty()){
+            if (dboard_names.size() != 1) throw std::runtime_error(
+                "A daughterboard name must be provided for multi-slot boards: " + subdev_spec.to_string()
+            );
+            pair.db_name == dboard_names.front();
+        }
+        uhd::assert_has(dboard_names, pair.db_name, xx_type + " dboard name");
         wax::obj dboard = mboard[named_prop_t(dboard_prop, pair.db_name)];
         uhd::assert_has(dboard[DBOARD_PROP_SUBDEV_NAMES].as<prop_names_t>(), pair.sd_name, xx_type + " subdev name");
     }
diff --git a/host/lib/usrp/subdev_spec.cpp b/host/lib/usrp/subdev_spec.cpp
index 765eecb3d..7a3e72867 100644
--- a/host/lib/usrp/subdev_spec.cpp
+++ b/host/lib/usrp/subdev_spec.cpp
@@ -53,13 +53,9 @@ std::string subdev_spec_t::to_pp_string(void) const{
     size_t count = 0;
     ss << "Subdevice Specification:" << std::endl;
     BOOST_FOREACH(const subdev_spec_pair_t &pair, *this){
-        std::string db_name = pair.db_name;
-        if (db_name == "") db_name = "0";
-        std::string sd_name = pair.sd_name;
-        if (sd_name == "") sd_name = "0";
         ss << boost::format(
             "    Channel %d: Daughterboard %s, Subdevice %s"
-        ) % (count++) % db_name % sd_name << std::endl;
+        ) % (count++) % pair.db_name % pair.sd_name << std::endl;
     }
     return ss.str();
 }
diff --git a/host/lib/usrp/usrp2/mboard_impl.cpp b/host/lib/usrp/usrp2/mboard_impl.cpp
index fe3ec6785..533b60bae 100644
--- a/host/lib/usrp/usrp2/mboard_impl.cpp
+++ b/host/lib/usrp/usrp2/mboard_impl.cpp
@@ -186,6 +186,8 @@ void usrp2_mboard_impl::issue_ddc_stream_cmd(const stream_cmd_t &stream_cmd){
 /***********************************************************************
  * MBoard Get Properties
  **********************************************************************/
+static const std::string dboard_name = "0";
+
 void usrp2_mboard_impl::get(const wax::obj &key_, wax::obj &val){
     wax::obj key; std::string name;
     boost::tie(key, name) = extract_named_prop(key_);
@@ -222,21 +224,21 @@ void usrp2_mboard_impl::get(const wax::obj &key_, wax::obj &val){
         return;
 
     case MBOARD_PROP_RX_DBOARD:
-        UHD_ASSERT_THROW(name == "");
+        UHD_ASSERT_THROW(name == dboard_name);
         val = _rx_dboard_proxy->get_link();
         return;
 
     case MBOARD_PROP_RX_DBOARD_NAMES:
-        val = prop_names_t(1, "");
+        val = prop_names_t(1, dboard_name);
         return;
 
     case MBOARD_PROP_TX_DBOARD:
-        UHD_ASSERT_THROW(name == "");
+        UHD_ASSERT_THROW(name == dboard_name);
         val = _tx_dboard_proxy->get_link();
         return;
 
     case MBOARD_PROP_TX_DBOARD_NAMES:
-        val = prop_names_t(1, "");
+        val = prop_names_t(1, dboard_name);
         return;
 
     case MBOARD_PROP_RX_DSP: