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view src/cs/drivers/drv_core/timer/timer2.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 This product is protected under copyright law and trade secret law as an unpublished work.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 : timer2.h Description :TIMER1 Project : drivers Author : pmonteil@tif.ti.com Patrice Monteil. Version number : 1.4 Date and time : 02/15/01 15:47:05 Previous delta : 02/15/01 15:47:05 SCCS file : /db/gsm_asp/db_ht96/dsp_0/gsw/rel_0/mcu_l1/release_gprs/mod/emu_p/EMU_P_FRED/drivers1/common/SCCS/s.timer2.h Sccs Id (SID) : '@(#) timer2.h 1.4 02/15/01 15:47:05 ' *****************************************************************************/ #include "l1sw.cfg" #if (OP_L1_STANDALONE == 0) #include "main/sys_types.h" #else #include "sys_types.h" #endif /**** DIONE TIMERs configuration register ****/ #define D_TIMER_ADDR 0xfffe6800 #define D_TIMER_CNTL_MASK 0x001f #define CNTL_D_TIMER_OFFSET 0x0000 #define LOAD_D_TIMER_OFFSET 0x0002 #define READ_D_TIMER_OFFSET 0x0004 #define D_TIMER_CNTL (D_TIMER_ADDR+CNTL_D_TIMER_OFFSET) #define D_TIMER_LOAD (D_TIMER_ADDR+LOAD_D_TIMER_OFFSET) #define D_TIMER_READ (D_TIMER_ADDR+READ_D_TIMER_OFFSET) #define D_TIMER_ST 0x0001 /* bit 0 */ #define D_TIMER_AR 0x0002 /* bit 1 */ #define D_TIMER_PTV 0x001c /* bits 4:2 */ #define D_TIMER_CLK_EN 0x0020 /* bit 5 */ #define D_TIMER_RUN 0x0021 /* bit 5 ,0 */ #define LOAD_TIM 0xffff /* bits 15:0 */ /* ----- Prototypes ----- */ SYS_UWORD16 Dtimer2_Get_cntlreg(void); void Dtimer2_AR(SYS_UWORD16 Ar); void Dtimer2_PTV(SYS_UWORD16 Ptv); void Dtimer2_Clken(SYS_UWORD16 En); void Dtimer2_Start (SYS_UWORD16 startStop); void Dtimer2_Init_cntl (SYS_UWORD16 St, SYS_UWORD16 Reload, SYS_UWORD16 clockScale, SYS_UWORD16 clkon); void Dtimer2_WriteValue (SYS_UWORD16 value); SYS_UWORD16 Dtimer2_ReadValue (void);