3 files changed, 10 insertions, 9 deletions
diff --git a/host/lib/rfnoc/graph_impl.cpp b/host/lib/rfnoc/graph_impl.cpp
index a2e0e64f4..d9e069993 100644
--- a/host/lib/rfnoc/graph_impl.cpp
+++ b/host/lib/rfnoc/graph_impl.cpp
@@ -139,11 +139,12 @@ void graph_impl::connect(
             src_block_port
     );
     // On the same crossbar, use lots of FC packets
-    size_t bytes_per_response = std::ceil<size_t>(buf_size_bytes / uhd::rfnoc::DEFAULT_FC_XBAR_RESPONSE_FREQ);
+    size_t bytes_per_response = buf_size_bytes / uhd::rfnoc::DEFAULT_FC_XBAR_RESPONSE_FREQ;
     // Over the network, use less or we'd flood the transport
     if (sid.get_src_addr() != sid.get_dst_addr()) {
-        bytes_per_response = std::ceil<size_t>(buf_size_bytes / uhd::rfnoc::DEFAULT_FC_TX_RESPONSE_FREQ);
+        bytes_per_response = buf_size_bytes / uhd::rfnoc::DEFAULT_FC_TX_RESPONSE_FREQ;
     }
+    UHD_ASSERT_THROW(bytes_per_response != 0);
     dst->configure_flow_control_in(
             bytes_per_response,
             dst_block_port
diff --git a/host/lib/rfnoc/sink_block_ctrl_base.cpp b/host/lib/rfnoc/sink_block_ctrl_base.cpp
index 1562e134b..d14fe2f38 100644
--- a/host/lib/rfnoc/sink_block_ctrl_base.cpp
+++ b/host/lib/rfnoc/sink_block_ctrl_base.cpp
@@ -52,8 +52,8 @@ size_t sink_block_ctrl_base::get_fifo_size(size_t block_port) const {
 }
 
 void sink_block_ctrl_base::configure_flow_control_in(
-        size_t bytes,
-        size_t block_port
+        const size_t bytes,
+        const size_t block_port
 ) {
     UHD_RFNOC_BLOCK_TRACE() << boost::format("sink_block_ctrl_base::configure_flow_control_in(bytes=%d)") % bytes;
 
diff --git a/host/lib/rfnoc/source_block_ctrl_base.cpp b/host/lib/rfnoc/source_block_ctrl_base.cpp
index afec6ba1b..0f1c31e4f 100644
--- a/host/lib/rfnoc/source_block_ctrl_base.cpp
+++ b/host/lib/rfnoc/source_block_ctrl_base.cpp
@@ -77,10 +77,10 @@ void source_block_ctrl_base::set_destination(
 }
 
 void source_block_ctrl_base::configure_flow_control_out(
-            bool enable_fc_output,
-            size_t buf_size_bytes,
-            size_t pkt_limit,
-            size_t block_port,
+            const bool enable_fc_output,
+            const size_t buf_size_bytes,
+            const size_t pkt_limit,
+            const size_t block_port,
             UHD_UNUSED(const uhd::sid_t &sid)
 ) {
     UHD_RFNOC_BLOCK_TRACE() << "source_block_ctrl_base::configure_flow_control_out() buf_size_bytes==" << buf_size_bytes;
@@ -113,7 +113,7 @@ void source_block_ctrl_base::configure_flow_control_out(
     //based flow control
     const bool enable_byte_fc = (buf_size_bytes != 0);
     const bool enable_pkt_cnt_fc = (pkt_limit != 0);
-    const size_t config = enable_fc_output + (enable_byte_fc << 1) + (enable_pkt_cnt_fc << 2);
+    const uint32_t config = (enable_fc_output ? 1 : 0) | (enable_byte_fc << 1) | (enable_pkt_cnt_fc << 2);
 
     //Resize the FC window.
     //Precondition: No data can be buffered upstream.