RETRY_USECS
i += RETRY_USECS) {
drv_usecwait(RETRY_USECS);
i += RETRY_USECS) {
drv_usecwait(RETRY_USECS);
i += RETRY_USECS) {
drv_usecwait(RETRY_USECS);
i += RETRY_USECS) {
drv_usecwait(RETRY_USECS);