FreeCalypso > hg > fc-tourmaline
view src/ui/bmi/mmiBlkResources.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 | 8142e6773a49 |
| children |
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#ifndef _MMI_BlkResources_H_ #define _MMI_BlkResources_H_ #define ALLOC_MEMORY mfwAlloc #define FREE_MEMORY mfwFree /******************************************************************************* CONDAT (UK) ******************************************************************************** This software product is the property of Condat (UK) Ltd and may not be disclosed to any third party without the express permission of the owner. ******************************************************************************** $Project name: Basic MMI $Project code: BMI (6349) $Module: PhoneBook $File: MmiBlkResources.h $Revision: 1.0 $Author: Condat(UK) $Date: 25/10/00 ******************************************************************************** Description: The block resource manager handles a list of blocks of information, passing back pointers to the block of data on request. It provides a mechanism for mapping identifiers to strings, bitmaps, melodies or any other block of information. ******************************************************************************** $History: MmiBlkResources.h 25/10/00 Original Condat(UK) BMI version. $End *******************************************************************************/ /* Define the prototypes for the basic routines */ typedef void *tBlkHandle; typedef long int tBlkId; /* The initialisation routine must be called as part of the startup phase of the system, it will allocate working space for the block handler if required, and will initialise any structures required to maintain the correct operation of the functions. This routine must be called prior to invocation of any other block resource function */ tBlkHandle mmibr_Initialise( tBlkHandle BlkBase, int NumEntries ); /* The shutdown function can be called to free any allocations set up by the Initialise routine. In a running system this is unlikely to be called unless a catastrophic error has occurred and the system needs to be restarted. */ void mmibr_ShutDown( tBlkHandle *BlkRsrc ); /* We will adopt a mechanism where each block of data being provided will need to be returned to the block resource manager when it is no longer being used, this will provide an orthogonal approach when dealing with data coming from either ROM or dynamically allocated memory */ tBlkHandle mmibr_Fetch( tBlkHandle BlkRsrc, tBlkId Id ); /* Added to remove warning Aug - 11 */ EXTERN U8 *mfwAlloc (U32 size); /* End - Remove warning */ /******************************************************************************* End of File *******************************************************************************/ #endif