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HAL_PX4: always use the hrt semaphore based delay

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the up_udelay() could cause too much timing jitter
This commit is contained in:
Andrew Tridgell 2015-02-13 11:51:20 +11:00
parent 7f0060b881
commit 001643d5a3
1 changed files with 2 additions and 10 deletions
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12
libraries/AP_HAL_PX4/Scheduler.cpp
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@ -102,6 +102,7 @@ void PX4Scheduler::delay_microseconds_semaphore(uint16_t usec)
sem_t wait_semaphore;
struct hrt_call wait_call;
sem_init(&wait_semaphore, 0, 0);
memset(&wait_call, 0, sizeof(wait_call));
hrt_call_after(&wait_call, usec, (hrt_callout)sem_post, &wait_semaphore);
sem_wait(&wait_semaphore);
}
@ -109,16 +110,7 @@ void PX4Scheduler::delay_microseconds_semaphore(uint16_t usec)
void PX4Scheduler::delay_microseconds(uint16_t usec)
{
perf_begin(_perf_delay);
if (usec >= 500) {
delay_microseconds_semaphore(usec);
perf_end(_perf_delay);
return;
}
uint64_t start = micros64();
uint64_t dt;
while ((dt=(micros64() - start)) < usec) {
up_udelay(usec - dt);
}
delay_microseconds_semaphore(usec);
perf_end(_perf_delay);
}