fix(GPO): min suggested tip cap if there's congestion to avoid filter…

…ing through `DefaultIgnorePrice` (scroll-tech#883)

eth/gasprice/gasprice.go

@@ -38,7 +38,7 @@ const sampleNumber = 3 // Number of transactions sampled in a block
 
 var (
 	DefaultMaxPrice    = big.NewInt(500 * params.GWei)
-	DefaultIgnorePrice = big.NewInt(2 * params.Wei)
+	DefaultIgnorePrice = big.NewInt(1 * params.Wei)
 	DefaultBasePrice   = big.NewInt(0)
 )
 
@@ -194,10 +194,13 @@ func (oracle *Oracle) SuggestTipCap(ctx context.Context) (*big.Int, error) {
 	// high-priced txs are causing the suggested tip cap to be high.
 	pendingTxCount, _ := oracle.backend.Stats()
 	if pendingTxCount < oracle.congestedThreshold {
-		// Before Curie (EIP-1559), we need to return the total suggested gas price. After Curie we return 1 wei as the tip cap,
+		// Before Curie (EIP-1559), we need to return the total suggested gas price. After Curie we return 2 wei as the tip cap,
 		// as the base fee is set separately or added manually for legacy transactions.
-		// Set price to 1 as otherwise tx with a 0 tip might be filtered out by the default mempool config.
-		price := big.NewInt(1)
+		// 1. Set price to at least 1 as otherwise tx with a 0 tip might be filtered out by the default mempool config.
+		// 2. Since oracle.ignoreprice was set to 2 (DefaultIgnorePrice) before by default, we need to set the price
+		//    to 2 to avoid filtering in oracle.getBlockValues() by nodes that did not yet update to this version.
+		//    In the future we can set the price to 1 wei.
+		price := big.NewInt(2)
 		if !oracle.backend.ChainConfig().IsCurie(head.Number) {
 			price = oracle.defaultBasePrice
 		}

params/version.go

@@ -24,7 +24,7 @@ import (
 const (
 	VersionMajor = 5         // Major version component of the current release
 	VersionMinor = 5         // Minor version component of the current release
-	VersionPatch = 6         // Patch version component of the current release
+	VersionPatch = 7         // Patch version component of the current release
 	VersionMeta  = "mainnet" // Version metadata to append to the version string
 )