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.

#ifndef EXTDSPL_H
#define EXTDSPL_H
/* 
+----------------------------------------------------------------------------- 
|  Project :  
|  Modul   :  
+----------------------------------------------------------------------------- 
|  Copyright 2002 Texas Instruments Berlin, AG 
|                 All rights reserved. 
| 
|                 This file is confidential and a trade secret of Texas 
|                 Instruments Berlin, AG 
|                 The receipt of or possession of this file does not convey 
|                 any rights to reproduce or disclose its contents or to 
|                 manufacture, use, or sell anything it may describe, in 
|                 whole, or in part, without the specific written consent of 
|                 Texas Instruments Berlin, AG. 
+----------------------------------------------------------------------------- 
|  Purpose :  Definitions of the EXTDSPL service access point.
+----------------------------------------------------------------------------- 
*/ 


/*
 * Definition of the SAP
 */
#define SAP_EXTDSPL


/*
 * Mask for Opcodes
 */
#define EXTDSPL_DL  0x7F00
#define EXTDSPL_UL  0x3F00


/*
 * The primitves and their OPC's
 */
typedef struct 
{
  U32 dummy;
} T_EXTDSPL_CAP_REQ;

#define EXTDSPL_CAP_REQ 0x3F00


typedef struct 
{
  U32 dummy;
} T_EXTDSPL_DATA_REQ;

#define EXTDSPL_DATA_REQ 0x3F01


typedef struct 
{
  U16 width;
  U16 height;
  U16 bpp;
  U8  _dallign1;
  U8  _dallign2;
} T_EXTDSPL_CAP_IND;

#define EXTDSPL_CAP_IND 0x7F00


typedef struct 
{
  U16 col;
  U16 row;
  U16 width;
  U16 height;
  T_sdu sdu;
} T_EXTDSPL_DATA_IND;

#define EXTDSPL_DATA_IND 0x7F01


#endif /* EXTDSPL_H */