tests/kernel/sched/deadline fails on NRF5x boards

[spoorthik]

Commit: 02aa980

Execution log:

 ***** delaying boot 1000ms (per build configuration) *****
***** Booting Zephyr OS 1.13.0-rc2 (delayed boot 1000ms) *****
Running test suite suite_deadline
===================================================================
starting test - test_deadline

    Assertion failed at /zephyr.git/tests/kernel/sched/deadline/src/main.c:70: test_deadline: (n_exec == 0 is false)
threads ran too soon
FAIL - test_deadline
===================================================================
===================================================================

PROJECT EXECUTION FAILED

Platforms tested: nrf52840_pca10056:arm, nrf52_pca10040:arm, nrf51_pca10028:arm

[andyross]

Always NRFx... It's true that I underconstrained the scheduler setup -- maybe the main thread is already at the lowest priority on those boards?

[nashif]

CONFIG_BT=n and it works...
Something in the BT stack interferes with the test, suggest to add CONFIG_BT=n to the prj.conf

[andyross]

That's a good catch. Yeah, there are threads and priority selection done in the context of the BT and network layers, if it pushes the main thread to the bottom that could do it. If it doesn't, though, nothing should really "interfere" with the scheduling here. Agree with that for an immediate fix, but I should dig a little before closing this.

[andyross]

Suggested fix submitted, but please don't close until I can figure out why this is happening (strictly: it's not a problem with the EDF feature, the detected case is that the threads are running before the test's main entry point has blocked, which shouldn't happen). A quick look at the generated .config doesn't show anything obviously wrong.