[keymgr,keymgr_dpe] Don't block PRNG reseeding operations while proce…

…ssing commands A code comment mentioned that this was due to DV limitations but there are no signs that this limitation still exists. Removing this qualification of the seed enable signal is more efficient from an entropy consumption viewpoint as the entropy is anyway requested but just dropped in case of commands being processed currently. Co-authored-by: Andreas Kurth <[email protected]> Signed-off-by: Pirmin Vogel <[email protected]>
Razer6 · Sep 24, 2024 · eaf21ea · eaf21ea
1 parent f71bc93
commit eaf21ea
Showing 1 changed file with 1 addition and 6 deletions.
diff --git a/hw/ip/keymgr_dpe/rtl/keymgr_dpe.sv b/hw/ip/keymgr_dpe/rtl/keymgr_dpe.sv
@@ -209,12 +209,7 @@ module keymgr_dpe
     .clk_i,
     .rst_ni,
     .lfsr_en_i(ctrl_lfsr_en | data_lfsr_en | sideload_lfsr_en),
-    // The seed update is skipped if there is an ongoing keymgr transaction.
-    // This is not really done for any functional purpose but more to simplify
-    // DV. When an invalid operation is selected, the keymgr just starts transmitting
-    // whatever is at the prng output, however, this may cause a dv protocol violation
-    // if a reseed happens to coincide.
-    .seed_en_i(seed_en & ~reg2hw.start.q),
+    .seed_en_i(seed_en),
     .seed_i(seed),
     .entropy_i('0),
     .state_o(lfsr)