POLL_USEC
count = TIMEOUT_USEC / POLL_USEC;
usleep_range(POLL_USEC / 2, POLL_USEC);
POLL_USEC, TIMEOUT_USEC);
(sig & pwr_hw) == pwr_hw, POLL_USEC,
POLL_USEC, TIMEOUT_USEC);
for (t = 0; t <= timeout * 1000000; t += POLL_USEC) {
struct timeval tv = { .tv_usec = POLL_USEC, };