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esp32s2: port_get_raw_ticks: Use a more efficient, monotonic routine

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While trying to debug #3572, I noticed that I would frequently break in
the midst of gettimeofday and that the routine get_adjusted_boot_time
had to take and release locks.  Furthermore, we don't want "adjusted"
boot time, which could go forwards or backwards depending on the
adjustment (such as setting the clock used by gettimeofday() to the network
time)
This commit is contained in:
Jeff Epler 2020-11-17 17:45:12 -06:00
parent 1bc770c3dc
commit 9206925bf8
1 changed files with 5 additions and 5 deletions
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10
ports/esp32s2/supervisor/port.c
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@ -191,14 +191,14 @@ uint32_t port_get_saved_word(void) {
}
uint64_t port_get_raw_ticks(uint8_t* subticks) {
struct timeval tv_now;
gettimeofday(&tv_now, NULL);
// convert usec back to ticks
uint64_t all_subticks = (uint64_t)(tv_now.tv_usec * 2) / 71;
// Convert microseconds to subticks of 1/32768 seconds
// 32768/1000000 = 64/15625 in lowest terms
// this arithmetic overflows after 570 years
int64_t all_subticks = esp_timer_get_time() * 512 / 15625;
if (subticks != NULL) {
*subticks = all_subticks % 32;
}
return (uint64_t)tv_now.tv_sec * 1024L + all_subticks / 32;
return all_subticks / 32;
}
// Enable 1/1024 second tick.