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view src/g23m-fad/tcpip/include/rvm_ext_priorities.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 (2021-04-26) |
| parents | fa8dc04885d8 |
| children |
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/************************************************************************************* * * * Name rvm_ext_priorities.h * * * * Function this file priorities defintitions for basic SWEs * * It includes a file * * * Version 0.1 * * * * Date Modification * * ------------------------------------ * * 10/11/2000 Create * * * * Author Cristian Livadiotti (c-livadiotti@ti.com) * * * * (C) Copyright 2000 by Texas Instruments Incorporated, All Rights Reserved * * * * --------------------------------------------------------------------------------- * * * * History: * * * * 10/18/2001 - Updated for R2D by Christophe Favergeon * * * *************************************************************************************/ #ifndef __RVM_EXT_PRIORITIES_H_ #define __RVM_EXT_PRIORITIES_H_ /* PRIORITIES SETTING: */ /* All user priority should be set under 250: */ /* Higher values are reserved */ /* ** External Priority definitions */ #define RVM_EXPL_TASK_PRIORITY (240) #define RVM_OBX_TASK_PRIORITY (240) #define RVM_OPP_TASK_PRIORITY (240) #define RVM_SYN_TASK_PRIORITY (240) #define RVM_FTP_TASK_PRIORITY (240) #define RVM_RGUI_TASK_PRIORITY (240) #define RVM_R2D_TASK_PRIORITY (239) #define RVM_DEV1_TASK_PRIORITY (245) #define RVM_DEV2_TASK_PRIORITY (245) #define RVM_DEV3_TASK_PRIORITY (245) #define RVM_UVM_TASK_PRIORITY (245) #endif /* __RVM_EXT_PRIORITIES_H_ */