return default fee if not subnet-evm

Author: ceyonur

core/blockchain_reader.go

@@ -361,11 +361,15 @@ func (bc *BlockChain) SubscribeAcceptedTransactionEvent(ch chan<- NewTxsEvent) e
 }
 
 // GetFeeConfigAt returns the fee configuration and the last changed block number at [parent].
+// If Subnet-EVM is not activated, returns default fee config and nil block number.
 // If FeeManager is activated at [parent], returns the fee config in the precompile contract state.
 // Otherwise returns the fee config in the chain config.
 // Assumes that a valid configuration is stored when the precompile is activated.
 func (bc *BlockChain) GetFeeConfigAt(parent *types.Header) (commontype.FeeConfig, *big.Int, error) {
 	config := bc.Config()
+	if !config.IsSubnetEVM(parent.Time) {
+		return params.DefaultFeeConfig, nil, nil
+	}
 	if !config.IsPrecompileEnabled(feemanager.ContractAddress, parent.Time) {
 		return config.FeeConfig, common.Big0, nil
 	}

core/txpool/legacypool/legacypool.go

@@ -1818,6 +1818,8 @@ func (pool *LegacyPool) periodicBaseFeeUpdate() {
 	}
 }
 
+// updateBaseFee updates the base fee in the tx pool based on the current head block.
+// should only be called when the chain is in Subnet EVM.
 func (pool *LegacyPool) updateBaseFee() {
 	pool.mu.Lock()
 	defer pool.mu.Unlock()
@@ -1829,6 +1831,7 @@ func (pool *LegacyPool) updateBaseFee() {
 }
 
 // assumes lock is already held
+// should only be called when the chain is in Subnet EVM.
 func (pool *LegacyPool) updateBaseFeeAt(head *types.Header) error {
 	feeConfig, _, err := pool.chain.GetFeeConfigAt(head)
 	if err != nil {

eth/gasprice/gasprice.go

@@ -192,12 +192,8 @@ func NewOracle(backend OracleBackend, config Config) (*Oracle, error) {
 		}
 	}()
 	feeConfig, _, err := backend.GetFeeConfigAt(backend.LastAcceptedBlock().Header())
-	var minBaseFee *big.Int
 	if err != nil {
-		// resort back to chain config
 		return nil, fmt.Errorf("failed getting fee config in the oracle: %w", err)
-	} else {
-		minBaseFee = feeConfig.MinBaseFee
 	}
 	feeInfoProvider, err := newFeeInfoProvider(backend, minGasUsed.Uint64(), config.Blocks)
 	if err != nil {
@@ -206,7 +202,7 @@ func NewOracle(backend OracleBackend, config Config) (*Oracle, error) {
 	return &Oracle{
 		backend:             backend,
 		lastPrice:           minPrice,
-		lastBaseFee:         new(big.Int).Set(minBaseFee),
+		lastBaseFee:         new(big.Int).Set(feeConfig.MinBaseFee),
 		minPrice:            minPrice,
 		maxPrice:            maxPrice,
 		checkBlocks:         blocks,