PCI_EXP_DEVCAP_L1
encoding = FIELD_GET(PCI_EXP_DEVCAP_L1, endpoint->devcap);
u32 l1_lat = FIELD_GET(PCI_EXP_DEVCAP_L1, dev->devcap);
dev->devcap |= FIELD_PREP(PCI_EXP_DEVCAP_L1, 7);