Increase delta to 500 us. This value is still short enough to detect
incorrect behavior of the sleep_manager_can_deep_sleep_test_check() fun,
but allows the targets with low LP timer accuracy to pass, i.e.
NUCLEO_F429ZI.
You are allowed in POSIX / ANSI C to read and write on the same stream, but you
have to do an fseek in between read and write call (getc->fseek->putc)
Thanks @Alex-EEE for sharing the fix: https://github.com/ARMmbed/mbed-os/pull/7749
Added test case for verification of the behavior
Heap statistics are used for analysing heap stats, but it doesn't tell anything
about real heap usage or malloc overheads. Adding `overhead_size` element
will help users to get the real heap usage.
There is no problem with this test during the morph, but some issue has been noticed while testing new Jenkins CI in Oulu on NRF52_DK.
I was able to reproduce the issue locally. The difference between morph and local run is that CPU statistics are enabled on morph. This makes the difference and test passes.
The sleep test case perform sleep for 100 us, 200 us, ... ,1000 us in loop (us ticker wakes the board) and verifies if sleep time matches the assumption.
I got the following results:
sleep wake-up after
100 us ~100 us ok
200 us ~200 us ok
300 us ~300 us ok
400 us ~400 us ok
500 us ~14 us (??)
When requested sleep time is equal to 500 us some unexpected interrupt occurs which wakeup the board and force the test to fail.
Register state just after exit from sleep:
Control and State Register: 0x00400000 (ISRPENDING - Interrupt pending flag is set).
NVIC Interrupt Set-pending Register[0]: 0x00000004 (UARTE0_UART0_IRQn) or 0x00000200 (TIMER1_IRQn - timer used by us ticker).
UART interrupt is generated because of green-tea transmission. We know that it is performed while test is executed since we need to wait before going into deep-sleep since otherwise the transmission will be broken. So to take care of UART interrupt we need to wait before sleep test in the same way like it is done in deep-sleep test.
Test case was assuming that secure and unsecure SSID were on different
channels.
This is not a requirement and it should be OK to run on same channel.
Fixed the testcase by using +1 on channel number to get a wrong channel.
2.4GHz and 5GHz channels might be using the same SSID. Wifi scan
might also fail occasionally to find secure- and unsecure channels
on same scan so lets not assume that we'll find both.
Add a test to ensure that devices have at least 2K free ram
and 2K free heap. This test should be the first test that fails
due to running out of ram or heap.