1 files changed, 28 insertions, 31 deletions

diff --git a/host/lib/usrp/x300/x300_io_impl.cpp b/host/lib/usrp/x300/x300_io_impl.cpp
index 85de34a54..9263c9b44 100644
--- a/host/lib/usrp/x300/x300_io_impl.cpp
+++ b/host/lib/usrp/x300/x300_io_impl.cpp
@@ -242,6 +242,8 @@ struct x300_tx_fc_guts_t
     boost::shared_ptr<x300_impl::async_md_type> old_async_queue;
 };
 
+#define X300_ASYNC_EVENT_CODE_FLOW_CTRL 0
+
 static size_t get_tx_flow_control_window(size_t frame_size, const device_addr_t& tx_args)
 {
     double hw_buff_size = tx_args.cast<double>("send_buff_size", X300_TX_HW_BUFF_SIZE);
@@ -283,23 +285,28 @@ static void handle_tx_async_msgs(boost::shared_ptr<x300_tx_fc_guts_t> guts, zero
         return;
     }
 
-    //catch the flow control packets and react
-    if (endian_conv(packet_buff[if_packet_info.num_header_words32+0]) == 0)
-    {
-        const size_t seq = endian_conv(packet_buff[if_packet_info.num_header_words32+1]);
-        guts->seq_queue.push_with_haste(seq);
-        return;
-    }
-
     //fill in the async metadata
     async_metadata_t metadata;
     load_metadata_from_buff(
         endian_conv, metadata, if_packet_info, packet_buff,
         clock->get_master_clock_rate(), guts->stream_channel);
-    guts->async_queue->push_with_pop_on_full(metadata);
-    metadata.channel = guts->device_channel;
-    guts->old_async_queue->push_with_pop_on_full(metadata);
-    standard_async_msg_prints(metadata);
+
+    //The FC response and the burst ack are two indicators that the radio
+    //consumed packets. Use them to update the FC metadata
+    if (metadata.event_code == X300_ASYNC_EVENT_CODE_FLOW_CTRL or
+        metadata.event_code == async_metadata_t::EVENT_CODE_BURST_ACK
+    ) {
+        const size_t seq = metadata.user_payload[0];
+        guts->seq_queue.push_with_pop_on_full(seq);
+    }
+
+    //FC responses don't propagate up to the user so filter them here
+    if (metadata.event_code != X300_ASYNC_EVENT_CODE_FLOW_CTRL) {
+        guts->async_queue->push_with_pop_on_full(metadata);
+        metadata.channel = guts->device_channel;
+        guts->old_async_queue->push_with_pop_on_full(metadata);
+        standard_async_msg_prints(metadata);
+    }
 }
 
 static managed_send_buffer::sptr get_tx_buff_with_flowctrl(
@@ -319,7 +326,9 @@ static managed_send_buffer::sptr get_tx_buff_with_flowctrl(
     }
 
     managed_send_buffer::sptr buff = xport->get_send_buff(timeout);
-    if (buff) guts->last_seq_out++; //update seq, this will actually be a send
+    if (buff) {
+        guts->last_seq_out++; //update seq, this will actually be a send
+    }
     return buff;
 }
 
@@ -399,15 +408,9 @@ rx_streamer::sptr x300_impl::get_rx_stream(const uhd::stream_args_t &args_)
         both_xports_t xport = this->make_transport(mb_index, dest, X300_RADIO_DEST_PREFIX_RX, device_addr, data_sid);
         UHD_LOG << boost::format("data_sid = 0x%08x, actual recv_buff_size = %d\n") % data_sid % xport.recv_buff_size << std::endl;
 
-        //calculate packet size
-        static const size_t hdr_size = 0
-            + vrt::num_vrl_words32*sizeof(boost::uint32_t)
-            + vrt::max_if_hdr_words32*sizeof(boost::uint32_t)
-            + sizeof(vrt::if_packet_info_t().tlr) //forced to have trailer
-            - sizeof(vrt::if_packet_info_t().cid) //no class id ever used
-            - sizeof(vrt::if_packet_info_t().tsi) //no int time ever used
-        ;
-        const size_t bpp = xport.recv->get_recv_frame_size() - hdr_size; // bytes per packet
+	// To calculate the max number of samples per packet, we assume the maximum header length
+	// to avoid fragmentation should the entire header be used.
+        const size_t bpp = xport.recv->get_recv_frame_size() - X300_RX_MAX_HDR_LEN; // bytes per packet
         const size_t bpi = convert::get_bytes_per_item(args.otw_format); // bytes per item
         const size_t spp = unsigned(args.args.cast<double>("spp", bpp/bpi)); // samples per packet
 
@@ -568,15 +571,9 @@ tx_streamer::sptr x300_impl::get_tx_stream(const uhd::stream_args_t &args_)
         both_xports_t xport = this->make_transport(mb_index, dest, X300_RADIO_DEST_PREFIX_TX, device_addr, data_sid);
         UHD_LOG << boost::format("data_sid = 0x%08x\n") % data_sid << std::endl;
 
-        //calculate packet size
-        static const size_t hdr_size = 0
-            + vrt::num_vrl_words32*sizeof(boost::uint32_t)
-            + vrt::max_if_hdr_words32*sizeof(boost::uint32_t)
-            //+ sizeof(vrt::if_packet_info_t().tlr) //forced to have trailer
-            - sizeof(vrt::if_packet_info_t().cid) //no class id ever used
-            - sizeof(vrt::if_packet_info_t().tsi) //no int time ever used
-        ;
-        const size_t bpp = xport.send->get_send_frame_size() - hdr_size;
+	// To calculate the max number of samples per packet, we assume the maximum header length
+	// to avoid fragmentation should the entire header be used.
+        const size_t bpp = xport.send->get_send_frame_size() - X300_TX_MAX_HDR_LEN;
         const size_t bpi = convert::get_bytes_per_item(args.otw_format);
         const size_t spp = unsigned(args.args.cast<double>("spp", bpp/bpi));