diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h
index be750b22672a77d85c94ecde80ea9448a352fc54..bef1695af07833f05594a2831a3519557f434d7f 100644
--- a/include/uapi/linux/pci_regs.h
+++ b/include/uapi/linux/pci_regs.h
@@ -532,7 +532,7 @@
 #define  PCI_EXP_DEVSTA_TRPND	0x0020	/* Transactions Pending */
 #define PCI_CAP_EXP_RC_ENDPOINT_SIZEOF_V1	12	/* v1 endpoints without link end here */
 #define PCI_EXP_LNKCAP		0x0c	/* Link Capabilities */
-#define  PCI_EXP_LNKCAP_SLS	0x0000000f /* Supported Link Speeds */
+#define  PCI_EXP_LNKCAP_SLS	0x0000000f /* Max Link Speed (prior to PCIe r3.0: Supported Link Speeds) */
 #define  PCI_EXP_LNKCAP_SLS_2_5GB 0x00000001 /* LNKCAP2 SLS Vector bit 0 */
 #define  PCI_EXP_LNKCAP_SLS_5_0GB 0x00000002 /* LNKCAP2 SLS Vector bit 1 */
 #define  PCI_EXP_LNKCAP_SLS_8_0GB 0x00000003 /* LNKCAP2 SLS Vector bit 2 */