FreeCalypso > hg > fc-tourmaline
view cdg-hybrid/fflags.h @ 220:0ed36de51973
ABB semaphore protection overhaul
The ABB semaphone protection logic that came with TCS211 from TI
was broken in several ways:
* Some semaphore-protected functions were called from Application_Initialize()
context. NU_Obtain_Semaphore() called with NU_SUSPEND fails with
NU_INVALID_SUSPEND in this context, but the return value wasn't checked,
and NU_Release_Semaphore() would be called unconditionally at the end.
The latter call would increment the semaphore count past 1, making the
semaphore no longer binary and thus no longer effective for resource
protection. The fix is to check the return value from NU_Obtain_Semaphore()
and skip the NU_Release_Semaphore() call if the semaphore wasn't properly
obtained.
* Some SPI hardware manipulation was being done before entering the semaphore-
protected critical section. The fix is to reorder the code: first obtain
the semaphore, then do everything else.
* In the corner case of L1/DSP recovery, l1_abb_power_on() would call some
non-semaphore-protected ABB & SPI init functions. The fix is to skip those
calls in the case of recovery.
* A few additional corner cases existed, all of which are fixed by making
ABB semaphore protection 100% consistent for all ABB functions and code paths.
There is still one remaining problem of priority inversion: suppose a low-
priority task calls an ABB function, and some medium-priority task just happens
to preempt right in the middle of that semaphore-protected ABB operation. Then
the high-priority SPI task is locked out for a non-deterministic time until
that medium-priority task finishes its work and goes back to sleep. This
priority inversion problem remains outstanding for now.
author | Mychaela Falconia <falcon@freecalypso.org> |
---|---|
date | Mon, 26 Apr 2021 20:55:25 +0000 |
parents | 35f7a1dc9f7d |
children |
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/* * This version of fflags.h (ccdgen config file) is a FreeCalypso concoction. * Here I set all feature flags to OFF in order to create a configuration * that mimics the TCS211 program. */ #undef FF_PS_RSSI #undef SIM_PERS #undef FF_PHONE_LOCK #undef TI_PS_FF_AT_CMD_P_ECC #undef TI_PS_FF_REL99_AND_ABOVE #undef TI_DUAL_MODE #undef REL99 #undef FF_BHO #undef TI_PS_FF_EMR #undef TI_PS_FF_RTD #undef FF_EGPRS #undef REL4 #undef TI_PS_FF_TBF_EST_PACCH #undef TI_PS_FF_QUAD_BAND_SUPPORT