DASD_FEATURE_USEDIAG
if (device->features & DASD_FEATURE_USEDIAG) {
use_diag = (devmap->features & DASD_FEATURE_USEDIAG) != 0;
use_diag = (DASD_FEATURE_DEFAULT & DASD_FEATURE_USEDIAG) != 0;
devmap->features |= DASD_FEATURE_USEDIAG;
devmap->features &= ~DASD_FEATURE_USEDIAG;
if (!devmap->device && !(devmap->features & DASD_FEATURE_USEDIAG)) {
features |= DASD_FEATURE_USEDIAG;