struct opregion_header {
        u8 signature[16];
        u32 size;
-       u32 opregion_ver;
+       struct {
+               u8 rsvd;
+               u8 revision;
+               u8 minor;
+               u8 major;
+       }  __packed over;
        u8 bios_ver[32];
        u8 vbios_ver[16];
        u8 driver_ver[16];
        opregion->header = base;
        opregion->lid_state = base + ACPI_CLID;
 
+       DRM_DEBUG_DRIVER("ACPI OpRegion version %u.%u.%u\n",
+                        opregion->header->over.major,
+                        opregion->header->over.minor,
+                        opregion->header->over.revision);
+
        mboxes = opregion->header->mboxes;
        if (mboxes & MBOX_ACPI) {
                DRM_DEBUG_DRIVER("Public ACPI methods supported\n");
        if (dmi_check_system(intel_no_opregion_vbt))
                goto out;
 
-       if (opregion->header->opregion_ver >= 2 && opregion->asle &&
+       if (opregion->header->over.major >= 2 && opregion->asle &&
            opregion->asle->rvda && opregion->asle->rvds) {
                opregion->rvda = memremap(opregion->asle->rvda,
                                          opregion->asle->rvds,