non-handle interrupt causes context switch corruption in TI-RTOS

hi Todd,

the non-managed HWI just calculates a value for a 3p3z controller and updates a GPIO pin and PWM values. It just uses integer multiplication and addition.

#define _xsmmlar(a,c,acc) (((int32_t)(((int64_t)(a)*(c))>>32))+(acc))

inline void CNTRL_3p3zFixedUnified(CNTRL_DataFixedUnified* pCtrl)
{
	int32_t acc =0;

	acc = _xsmmlar(pCtrl->m_B3, pCtrl->m_E[2], acc); pCtrl->m_E[2] = pCtrl->m_E[1];
	acc = _xsmmlar(pCtrl->m_B2, pCtrl->m_E[1],acc); pCtrl->m_E[1] = pCtrl->m_E[0];
	acc = _xsmmlar(pCtrl->m_B1, pCtrl->m_E[0],acc); pCtrl->m_E[0] = pCtrl->m_Kerr*((pCtrl->m_Ref - pCtrl->m_FeedBack));
	acc = _xsmmlar(pCtrl->m_B0, pCtrl->m_E[0],acc);

	acc = _xsmmlar(pCtrl->m_A3, pCtrl->m_U[2],acc); pCtrl->m_U[2] = pCtrl->m_U[1];
	acc = _xsmmlar(pCtrl->m_A2, pCtrl->m_U[1],acc); pCtrl->m_U[1] = pCtrl->m_U[0];
	acc = _xsmmlar(pCtrl->m_A1, pCtrl->m_U[0],acc);

	pCtrl->m_Out = (uint32_t)acc;
}

__interrupt void HwiPwmFunc( void )
{
	HWREG(GPIO_PORTL_BASE + (GPIO_O_DATA + ((1<<2) << 2))) = 0xFF; //PL2 on

    Buck.m_Ref = m_AdcVlimit;
    Buck.m_FeedBack = m_AdcVout;
    CNTRL_3p3zFixedUnified(&Buck);

    HWREG(PWM0_BASE + PWM_GEN_0 + PWM_O_X_ISC) = PWM_INT_CNT_LOAD; //PWMGenIntClear(PWM0_BASE, PWM_GEN_0, PWM_INT_CNT_LOAD);
    HWREG(GPIO_PORTL_BASE + (GPIO_O_DATA + ((1<<2) << 2))) = 0x00; //PL2 off
}

cheers

Chris

Hi,

I've now reproduced the fault on a  MSP-EXP432P401R (that's two TI platforms that use TI-RTOS). You just need to add a break point to empty.c:line 50:"         ErrCount++;" and press run and look at the value of "ret". It will be corrupted.

    if (ret >= 0.0f && ret <= ADC_VALUE_MAX)
    {
    	//ok
    }
    else
    {
    	ErrCount++;
        //assert(ret >= 0.0f && ret <= ADC_VALUE_MAX);
    }
    return (uint32_t)ret;

Here's the project file.

7450.context_msp432.zip

cheers

Chris

Hi Christopher,

Thanks for submitting this post & project.  We have been able to reproduce the problem & have filed the SYSBIOS-208 bug to fix this in a future release.  

Regards,

-- Emmanuel