FreeCalypso > hg > fc-tourmaline
view src/cs/services/lls/lls_functions.c @ 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 | 5bf097aeaad7 |
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/** * @file lls_functions.c * * Implementation of LLS functions. * * @author Laurent Sollier (l-sollier@ti.com) * @version 0.1 */ /* * History: * * Date Author Modification * ---------------------------------------- * 03/12/2002 L Sollier Create * * * (C) Copyright 2002 by Texas Instruments Incorporated, All Rights Reserved */ #ifndef _WINDOWS #include "l1sw.cfg" #include "chipset.cfg" #endif #include "lls/lls_i.h" #include "lls/lls_api.h" #include "spi/spi_api.h" #include "rvf/rvf_api.h" /* Number of available equipment's */ #define NUMBER_OF_EQUIPMENT 3 /* Parameters for each EQUIPMENT */ typedef struct { T_LLS_EQUIPMENT equipment_sort; UINT16 page; UINT16 address; UINT8 bit; } T_EQUIPMENT_PARAM; /* Table of parameters for all the equipment's */ typedef T_EQUIPMENT_PARAM T_EQUIPMENT_PARAM_TABLE[NUMBER_OF_EQUIPMENT]; /* Definition of the parameters for the equipment */ #if (ANLG_FAM == 2) static T_EQUIPMENT_PARAM_TABLE equipment_param_table = { {LLS_LED_A, PAGE1, AUXLED, 0}, {LLS_BACKLIGHT, PAGE1, AUXLED, 1}, {LLS_PRECHARGE_LED, PAGE0, BCICTL2, 5} }; #else static T_EQUIPMENT_PARAM_TABLE equipment_param_table = {0}; #endif /* Save of the action to perform */ typedef struct { T_LLS_EQUIPMENT equipment_index; UINT8 action; } T_ACTION; static T_ACTION action_to_perform = {0}; /* Mutex used to protect perform only one action simultaneously */ static T_RVF_MUTEX mutex; /** * @name Functions implementation * */ /*@{*/ /** * function: lls_initialize */ T_RV_RET lls_initialize(void) { T_RV_RET ret = RV_OK; UINT8 i; /* Mutex initialization */ ret = rvf_initialize_mutex(&mutex); if (ret != RVF_OK) return RV_INTERNAL_ERR; /* Initialisation of the equipment at SWITCH_OFF */ for (i = 0; i < NUMBER_OF_EQUIPMENT; i++) { ret = lls_switch_off(equipment_param_table[i].equipment_sort); if (ret != RV_OK) return RV_INTERNAL_ERR; } return RV_OK; } /** * function: lls_kill_service */ T_RV_RET lls_kill_service(void) { T_RV_RET ret = RV_OK; ret = rvf_delete_mutex(&mutex); if (ret != RVF_OK) return RV_INTERNAL_ERR; return ret; } /** * function: lls_callback_equipment_status */ void lls_callback_equipment_status(UINT16* equipment_status) { T_RV_RET ret = RV_OK; UINT16 new_equipment_status = *equipment_status; LLS_SEND_TRACE_PARAM("LLS: Received equipment status", (UINT32) new_equipment_status, RV_TRACE_LEVEL_DEBUG_LOW); if (action_to_perform.action == SWITCH_ON) new_equipment_status |= 1 << equipment_param_table[action_to_perform.equipment_index].bit; else new_equipment_status &= ~(1 << equipment_param_table[action_to_perform.equipment_index].bit); LLS_SEND_TRACE_PARAM("LLS: New equipment status", (UINT32) new_equipment_status, RV_TRACE_LEVEL_DEBUG_LOW); ret = spi_abb_write(equipment_param_table[action_to_perform.equipment_index].page, equipment_param_table[action_to_perform.equipment_index].address, new_equipment_status); if (ret != RV_OK) LLS_SEND_TRACE("LLS: Error on SPI read", RV_TRACE_LEVEL_ERROR); rvf_unlock_mutex(&mutex); } /** * function: lls_manage_equipment */ T_RV_RET lls_manage_equipment(UINT8 equipment_index, UINT8 action) { T_RV_RET ret = RV_OK; /* Lock mutex until response from SPI is received */ rvf_lock_mutex(&mutex); /* Save action to do */ action_to_perform.equipment_index = equipment_index; action_to_perform.action = action; ret = spi_abb_read(equipment_param_table[equipment_index].page, equipment_param_table[equipment_index].address, lls_callback_equipment_status); if (ret != RV_OK) LLS_SEND_TRACE("LLS: Error on SPI read", RV_TRACE_LEVEL_ERROR); return ret; } /** * function: lls_search_index */ T_RV_RET lls_search_index(T_LLS_EQUIPMENT equipment, UINT8* equipment_index) { T_RV_RET ret = RV_OK; UINT8 i; for (i = 0; i < NUMBER_OF_EQUIPMENT; i++) if (equipment == equipment_param_table[i].equipment_sort) { *equipment_index = i; return RV_OK; } return RV_INVALID_PARAMETER; } /*@}*/