From fac972bfe62f9f365f62082301f8100c4b77ccf2 Mon Sep 17 00:00:00 2001
From: Alex Forencich <alex@alexforencich.com>
Date: Tue, 22 Jan 2019 22:50:15 -0800
Subject: [PATCH] RC channel backpressure fix

---
 rtl/pcie_us_axi_dma_rd.v | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/rtl/pcie_us_axi_dma_rd.v b/rtl/pcie_us_axi_dma_rd.v
index c12f261..f79ca25 100644
--- a/rtl/pcie_us_axi_dma_rd.v
+++ b/rtl/pcie_us_axi_dma_rd.v
@@ -687,10 +687,11 @@ always @* begin
                         tlp_state_next = TLP_STATE_WAIT_END;
                     end
                 end else begin
+                    s_axis_rc_tready_next = 1'b0;
                     tlp_state_next = TLP_STATE_IDLE;
                 end
             end else begin
-                s_axis_rc_tready_next = !m_axi_awvalid || m_axi_awready;
+                s_axis_rc_tready_next = 1'b1;
 
                 if (s_axis_rc_tready && s_axis_rc_tvalid) begin
                     // header fields
@@ -723,13 +724,15 @@ always @* begin
                         final_cpl_next = 1'b1;
                     end
 
-                    s_axis_rc_tready_next = 1'b0;
                     if (s_axis_rc_tlast) begin
+                        s_axis_rc_tready_next = !m_axi_awvalid || m_axi_awready;
                         tlp_state_next = TLP_STATE_IDLE;
                     end else begin
+                        s_axis_rc_tready_next = 1'b0;
                         tlp_state_next = TLP_STATE_HEADER;
                     end
                 end else begin
+                    s_axis_rc_tready_next = !m_axi_awvalid || m_axi_awready;
                     tlp_state_next = TLP_STATE_IDLE;
                 end
             end