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| author | Stefan Kerkmann <karlk90@pm.me> | 2022-07-11 15:17:05 +0200 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2022-07-11 15:17:05 +0200 |
| commit | 3f5dc472965e6a5b8efe60e33c7b6c2d18d92008 (patch) | |
| tree | c60357db5312ccbaae608c47edd77982ad1c17ad /platforms/chibios/_wait.h | |
| parent | 57021d63582718635f87ba661f40683e98ba59da (diff) | |
[Core] Use polled waiting on ChibiOS platforms that support it (#17607)
* Use polled waiting on platforms that support it
Due to context switching overhead waiting a very short amount of time on
a sleeping thread is often not accurate and in fact not usable for timing
critical usage i.e. in a driver. Thus we use polled waiting for ranges
in the us range on platforms that support it instead. The fallback is
the thread sleeping mechanism.
This includes:
* ARM platforms with CYCCNT register (ARMv7, ARMv8) this is
incremented at CPU clock frequency
* GD32VF103 RISC-V port with CSR_MCYCLE register this is incremented at
CPU clock frequency
* RP2040 ARMv6 port which uses the integrated timer peripheral which is
incremented with a fixed 1MHz frequency
* Use wait_us() instead of chSysPolledDelayX
...as it is powered by busy waiting now.
* Add chibios waiting methods test bench
Diffstat (limited to 'platforms/chibios/_wait.h')
| -rw-r--r-- | platforms/chibios/_wait.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/platforms/chibios/_wait.h b/platforms/chibios/_wait.h index 2f36c64a2e..21cdffe11a 100644 --- a/platforms/chibios/_wait.h +++ b/platforms/chibios/_wait.h @@ -30,6 +30,11 @@ #ifdef WAIT_US_TIMER void wait_us(uint16_t duration); +#elif PORT_SUPPORTS_RT == TRUE +# define wait_us(us) \ + do { \ + chSysPolledDelayX(US2RTC(REALTIME_COUNTER_CLOCK, us)); \ + } while (0) #else # define wait_us(us) \ do { \ |