Delta calculation from lp_ticker_set_interrupt() function:
delta_us = timestamp > now_us ? timestamp - now_us : (uint32_t)((uint64_t)timestamp + 0xFFFFFFFF - now_us);
Lets assume that timestam == now_us.
Expected delta value should be 0 and in this current version is 0xFFFFFFFF.
The following condition:
timestamp > now_us
should have the following form:
timestamp >= now_us
Additionally modified us ticker driver to provide the same logic.
If NVIC_NUM_VECTORS is larger than the space allocated by the vector
table in ram (__ram_vector_table_size__) then the call to mbed_cpy_nvic
during boot will corrupt valid data, which can lead to a crash. This
patch fixes the declared number of vectors on the KL27Z, KL43Z and
KL82Z to fix this crash.
fire_interrupt function should be used for events in the past. As we have now
64bit timestamp, we can figure out what is in the past, and ask a target to invoke
an interrupt immediately. The previous attemps in the target HAL tickers were not ideal, as it can wrap around easily (16 or 32 bit counters). This new
functionality should solve this problem.
set_interrupt for tickers in HAL code should not handle anything but the next match interrupt. If it was in the past is handled by the upper layer.
It is possible that we are setting next event to the close future, so once it is set it is already in the past. Therefore we add a check after set interrupt to verify it is in future.
If it is not, we fire interrupt immediately. This results in
two events - first one immediate, correct one. The second one might be scheduled in far future (almost entire ticker range),
that should be discarded.
The specification for the fire_interrupts are:
- should set pending bit for the ticker interrupt (as soon as possible),
the event we are scheduling is already in the past, and we do not want to skip
any events
- no arguments are provided, neither return value, not needed
- ticker should be initialized prior calling this function (no need to check if it is already initialized)
All our targets provide this new functionality, removing old misleading if (timestamp is in the past) checks.
When initializing the RTC on Kinetis devices, handle the case where
the time overflow interrupt is pending and the case where the time
alarm flag is pending. These flags persist across reset and if not
handled will cause a crash when powering up the low power ticker.
This problem manifested as a lp_ticker test failure on the K22F and
K64F on CI only when running a nightly. This problem has been present
but was made obvious by PR #4094 which configures all tickers to
interrupt at least every MBED_TICKER_INTERRUPT_TIMESTAMP_MAX_DELTA
(~31 minutes). This caused the RTC alarm to fire 31 minutes after the lp_ticker
or lp_timeout test and caused the next run of the lp_ticker test to
crash on boot.
Przemyslaw Stekiel
Maciej Rogozinski
sarahmarshy
Jimmy Brisson
Mahadevan Mahesh
maclobdell
Martin Kojtal
Dexter Fryar
Russ Butler
Deepika
Anna Bridge
Sam Grove
Bartek Szatkowski