can't get Interrupt Exception HWI hardware handler to be active

Hello,

I'm having a dropped interrupt, with an OMAP-L138/C6748 DSP.  I can see that it is being dropped in the INTXSTAT registers, which shows event "DROP YES" and NUM4 for both SYSINT and CPUINT, which is my interrupt for T64P0_TINT_12 (EventId = 4), which I've assigned to INT4, via the INTMUX1 register, and an entry in the sys-bios .cfg file.  It still hits that interrupt in code, but the timing is not right, and I wonder if it's the drops.  So I am trying to add a hardware handler for the INTERR signal, which I've assigned to INT5 via INTMUX1 register, and the following entry in the sys-bios .cfg file:

    var hwi_5_params = new Hwi.Params();
    hwi_5_params.instance.name = "hwi_name_interr";
    hwi_5_params.arg = 0
    Program.global.interr = Hwi.create( 5, "&hwi_fxn_interr", hwi_5_params );

where hwi_fxn_interr is a hardware service routine

void hwi_fxn_interr( void )
{
    static uint16_t cnt_0 = 0U;

    if ( ++cnt_0 == NUM_CNT_0 )

    {
        cnt_0 = 0U;
    }
}

that has nothing in it right now, except a dummy counter increment I'm trying to break on, but which never occurs, even though INTXSTAT is saying that there is a dropped interrupt which should result in this interrupt exception occurring and hitting the hwi_fxn_interrupt routine.

Please advise on any ways to to debug this.

Regards,

Robert