modules/swcore: fix rcv_fsm conditional to prevent false force free

Without this fix, when previous frame was whole dropped, transfer fsm was still in DROP state, while RCV fsm was going to S_IDLE. In that case, RCV fsm saw tp_drop high and it was doing force_free of a correctly received frame (the one before dropped frame). The conditional statement is needed, but it had to be fixed to work according to description in the comment - i.e. dropping frame when RTU decision is very late.

modules/swcore: fix rcv_fsm conditional to prevent false force free
Without this fix, when previous frame was whole dropped, transfer fsm was still in DROP state, while RCV fsm was going to S_IDLE. In that case, RCV fsm saw tp_drop high and it was doing force_free of a correctly received frame (the one before dropped frame). The conditional statement is needed, but it had to be fixed to work according to description in the comment - i.e. dropping frame when RTU decision is very late.
4618fd1f · Grzegorz Daniluk · 22e38c23 · 4618fd1f
Commit 4618fd1f authored Mar 26, 2015 by Grzegorz Daniluk
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xswc_input_block.vhd modules/wrsw_swcore/xswc_input_block.vhd +2 -1

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--- a/modules/wrsw_swcore/xswc_input_block.vhd
+++ b/modules/wrsw_swcore/xswc_input_block.vhd
@@ -822,7 +822,7 @@ begin  --archS_PCKSTART_SET_AND_REQ
            snk_stall_force_l <= '1';
            in_pck_dvalid_d0  <= '0';
            in_pck_dat_d0     <= (others => '0');
-            rtu_rsp_abort_o     <= '0';
+            rtu_rsp_abort_o   <= '0';

            -- Sync with trasnfer_pck FSM and ll_write FSM: 
            if(lw_sync_first_stage = '1' and tp_sync = '1') then
@@ -836,6 +836,7 @@ begin  --archS_PCKSTART_SET_AND_REQ
              -- in such case, we will get tp_drop before getting tp_sync, but we will
              -- still have tp_drop when finally tp_sync is HIGH, so this is why the order of if's
            elsif(tp_drop            = '1'   and  -- transfer_pck state indicates the drop decision
+                  s_transfer_pck /= S_DROP   and
                  mmu_force_free_req = '0') then  -- the pck is not being freed yet
              
              mmu_force_free_addr <= current_pckstart_pageaddr;