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view src/cs/drivers/drv_core/timer/timer.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 | 4e78acac3d88 |
| children |
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/******************************************************************************* TEXAS INSTRUMENTS INCORPORATED PROPRIETARY INFORMATION Property of Texas Instruments -- For Unrestricted Internal Use Only Unauthorized reproduction and/or distribution is strictly prohibited. This product is protected under copyright law and trade secret law as an unpublished work. Created 1987, (C) Copyright 1997 Texas Instruments. All rights reserved. Filename : timer.h Description : timer.c header Project : drivers Author : pmonteil@tif.ti.com Patrice Monteil. Version number : 1.3 Date and time : 07/23/98 16:25:53 Previous delta : 07/23/98 16:25:52 SCCS file : /db/gsm_asp/db_ht96/dsp_0/gsw/rel_0/mcu_l1/release1.5/mod/emu/EMU_MCMP/eva3_drivers/source/SCCS/s.timer.h Sccs Id (SID) : '@(#) timer.h 1.3 07/23/98 16:25:53 ' *****************************************************************************/ #include "l1sw.cfg" #if (OP_L1_STANDALONE == 0) #include "main/sys_types.h" #else #include "sys_types.h" #endif #define TIMER_CNTL_REG MEM_TIMER_ADDR /* watchdog Control Timer register */ #define TIMER_ST 0x0080 #define TIMER_AR 0x0100 #define TIMER_PTV 0x0e00 #define TIMER_CNTL_MASK 0x0f80 #define TIMER_MODE_MASK 0x80ff #define TIMER_LOAD_REG (MEM_TIMER_ADDR + 0x02) /* Timer load register */ #define TIMER_READ_REG (MEM_TIMER_ADDR + 0x02) /* Timer read register */ #define TIMER_MODE_REG (MEM_TIMER_ADDR + 0x04) /* Timer mode register */ #define TIMER_WDOG 0x8000 /* watch dog */ #define START_STOP 1 /*to start or stop a timer */ #define AR 0x0002 #define PTV 0x001c #define TIMER_CLK_EN 0x0020 #define TIMER1_CNTL (MEM_TIMER1 + 0x00) #define TIMER1_LOAD_TIM (MEM_TIMER1 + 0x02) #define TIMER1_READ_TIM (MEM_TIMER1 + 0x04) #define TIMER2_CNTL (MEM_TIMER2 + 0x00) #define TIMER2_LOAD_TIM (MEM_TIMER2 + 0x02) #define TIMER2_READ_TIM (MEM_TIMER2 + 0x04) /*-------------------------------------------------------------- * TIMER_START_STOP () *-------------------------------------------------------------- * Parameters : start or stop command * Return : none * Functionality : Start or Stop the timer *--------------------------------------------------------------*/ #define TIMER_START_STOP(startStop) ((startStop) ? ((* (volatile SYS_UWORD16 *) TIMER_CNTL_REG) |= TIMER_ST) : \ ((* (volatile SYS_UWORD16 *) TIMER_CNTL_REG) &= ~TIMER_ST)) /* Prototype of the functions */ void TM_ResetTimer (SYS_UWORD16 timerNum, SYS_UWORD16 countValue, SYS_UWORD16 autoReload, SYS_UWORD16 clockScale); void TM_StopTimer (int timerNum); void TM_StartTimer (int timerNum); SYS_UWORD16 TM_ReadTimer (int timerNum); void TM_DisableWatchdog(void); void TM_EnableWatchdog(void); void TM_ResetWatchdog(SYS_UWORD16 cnt); void TM_EnableTimer (int timerNum); void TM_DisableTimer (int timerNum); SYS_UWORD16 TIMER_Read (unsigned short); void TIMER_WriteValue (SYS_UWORD16); unsigned short TIMER_ReadValue (void);