wr_mini_nic: go through RX_MEM_FLUSH only when needed

Otherwise we do twice the same write to memory and we permanently lose one nrx_avail. This way, after some time minic may drop frames because it will think its buffer has not enough space (based on nrx_avail value).

wr_mini_nic: go through RX_MEM_FLUSH only when needed
Otherwise we do twice the same write to memory and we permanently lose one nrx_avail. This way, after some time minic may drop frames because it will think its buffer has not enough space (based on nrx_avail value).
221a6143 · Grzegorz Daniluk · a1075fd9 · 221a6143
Commit 221a6143 authored Oct 20, 2015 by Grzegorz Daniluk
Hide whitespace changes
Inline Side-by-side

Showing with 6 additions and 2 deletions

wr_mini_nic.vhd modules/wr_mini_nic/wr_mini_nic.vhd +6 -2

No files found.
--- a/modules/wr_mini_nic/wr_mini_nic.vhd
+++ b/modules/wr_mini_nic/wr_mini_nic.vhd
@@ -809,8 +809,12 @@ begin  -- behavioral
                  --nrx_error <= '1' when nrx_stat_error='1' or nrx_avail=to_unsigned(0, nrx_avail'length) else '0';
                  nrx_done <= '1';

-                  -- flush the remaining packet data into the DMA buffer
-                  nrx_state <= RX_MEM_FLUSH;
+                  -- flush the remaining packet data into the DMA buffer if needed
+                  if(nrx_toggle='1') then
+                    nrx_state <= RX_MEM_FLUSH;
+                  else
+                    nrx_state <= RX_UPDATE_DESC;
+                  end if;

                  if(nrx_valid = '1' or nrx_toggle = '1') then
                    if nrx_mem_a + 1 >= nrx_bufstart + nrx_bufsize then