diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index adae3e04c8c3..eda82a771ab8 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -14,6 +14,12 @@
 #define PCI_EXP_AER_FLAGS	(PCI_EXP_DEVCTL_CERE | PCI_EXP_DEVCTL_NFERE | \
 				 PCI_EXP_DEVCTL_FERE | PCI_EXP_DEVCTL_URRE)
 
+/*
+ * PCIe r6.0, sec 5.3.3.2.1 <PME Synchronization>
+ * Recommends 1ms to 10ms timeout to check L2 ready.
+ */
+#define PCIE_PME_TO_L2_TIMEOUT_US	10000
+
 extern const unsigned char pcie_link_speed[];
 extern bool pci_early_dump;