sequencer: Use higher sequencer drift for Celo (#251)

Closes celo-org/celo-blockchain-planning#629

op-node/rollup/chain_spec.go

@@ -27,6 +27,12 @@ const (
 // ChainSpec instead of reading the rollup configuration field directly.
 const maxSequencerDriftFjord = 1800
 
+// Normal OP chains wait for five confirmations while Celo waits for finalization, which can take
+// up to 3 * 32 blocks. So we should allow for more drift to compensate.
+// 3 * 32 - 5 = 91 blocks
+// 91 * 12s block time = 1092
+const maxSequencerDriftCelo = maxSequencerDriftFjord + 1092
+
 type ForkName string
 
 const (
@@ -105,7 +111,11 @@ func (s *ChainSpec) IsFeatMaxSequencerDriftConstant(t uint64) bool {
 // should always be queried via the ChainSpec.
 func (s *ChainSpec) MaxSequencerDrift(t uint64) uint64 {
 	if s.IsFeatMaxSequencerDriftConstant(t) {
-		return maxSequencerDriftFjord
+		if s.config.IsCel2(t) {
+			return maxSequencerDriftCelo
+		} else {
+			return maxSequencerDriftFjord
+		}
 	}
 	return s.config.MaxSequencerDrift
 }

op-node/rollup/types.go

@@ -408,6 +408,10 @@ func (c *Config) IsInterop(timestamp uint64) bool {
 	return c.InteropTime != nil && timestamp >= *c.InteropTime
 }
 
+func (c *Config) IsCel2(timestamp uint64) bool {
+	return c.Cel2Time != nil && timestamp >= *c.Cel2Time
+}
+
 func (c *Config) IsRegolithActivationBlock(l2BlockTime uint64) bool {
 	return c.IsRegolith(l2BlockTime) &&
 		l2BlockTime >= c.BlockTime &&