diff --git a/arch/ia64/mm/tlb.c b/arch/ia64/mm/tlb.c
index d52ec4e..8caf424 100644
--- a/arch/ia64/mm/tlb.c
+++ b/arch/ia64/mm/tlb.c
@@ -168,7 +168,10 @@
 	static int firstcpu = 1;
 
 	if (toolatetochangeptcgsem) {
-		BUG_ON(max_purges < nptcg);
+		if (nptcg_from == NPTCG_FROM_PAL && max_purges == 0)
+			BUG_ON(1 < nptcg);
+		else
+			BUG_ON(max_purges < nptcg);
 		return;
 	}