When the define LPTICKER_DELAY_TICKS is set deep sleep can be randomly
disallowed when using the low power ticker. This is because a Timer
object, which locks deep sleep, is used to protect from back-to-back
writes to lp tickers which can't support that. This causes tests which
assert that deep sleep is allowed to intermittently fail.
To fix this intermittent failure this patch adds the function
sleep_manager_can_deep_sleep_test_check() which checks if deep sleep
is allowed over a duration. It updates all the tests to use
sleep_manager_can_deep_sleep_test_check() rather
than sleep_manager_can_deep_sleep() so the tests work even if deep
sleep is spuriously blocked.
Serial buffer must be flushed before entering deep sleep mode. In the test this is done by the additional delay which is implemented on the busy loop which decrements given value down to 0 (`void wait_cycles(volatile unsigned int cycles)`). This solution is not appropriate since it is very target specific and the cycles value has been already increased few times. Additionally very big number of loop cycles which is suitable for fast targets may take much longer on slower boards and results in test timeout.
It has been verified that 20ms is sufficient delay for the green-tea transmission. In this test we cannot simply use `wait_ms(20)` since this potentially may put board to sleep and wake up using lp ticker. The test re-initialzies the lp ticker(disables ticker interrupt) and this operation may break the schedule and time tracing by the upper layer. But we can use us ticker which is not affected by this test. The solution is to add a delay routine based on busy loop and us ticker only. This way are able to wait exactly 20 ms.
As we do not include rtx_lib header file anymore, these symbols are not available.
Use core util for if ISR is active. And for OS tick, pull in os_tick header file.
Remove the direct use of the microsecond and low power ticker from
the tests. This enforces that sleep mode is properly locked when
using timers. Furthermore, this prepares the codebase for new ticker
changes which allow differing clock frequencies and timer bit widths.
The lp_ticker test overrides the default ticker handler for the
low power ticker. This stops all other low power TimerEvents in the
system, including the ones for tickless, from getting called. Because
of this devices with tickless enabled malfunction during this test.
This patch fixes this problem by passing all lp ticker events it did
not trigger on to the TimerEvent irq handler.
Russ Butler
Martin Kojtal
Przemyslaw Stekiel
Bartek Szatkowski
jeromecoutant
Martin Kojtal
Russ Butler
Vincent Coubard
Mahadevan Mahesh
Brian Daniels
svastm