cmx_sync_write_SCR
if ((rv = cmx_sync_write_SCR(sc, SCR_READER_TO_HOST_DONE)) != 0) {
if ((rv = cmx_sync_write_SCR(sc, SCR_HOST_TO_READER_START)) != 0) {
cmx_sync_write_SCR(sc, SCR_HOST_TO_READER_DONE);
if ((rv = cmx_sync_write_SCR(sc, SCR_HOST_TO_READER_DONE)) != 0) {