GPIO interrupt on DSP Tesla vs. M3 Ducati (OMAP4)

The following simple BIOS/Syslink code works on Cortex-M3 Ducati:

Hwi_Params hwiParams;
Error_Block eb;
Hwi_Params_init(&hwiParams);
Error_init(&eb);
hwiParams.arg = 0;
hwiParams.eventId = 10;
hwiParams.maskSetting = Hwi_MaskingOption_SELF;
hwiParams.enableInt = TRUE;
Hwi_create(GPIO1_IRQ, IsrGPIO1, &hwiParams, &eb);
if (Error_check(&eb)) {INFO("Error\n");}
Hwi_enable();

while it doesn't work on DSP Tesla (GPIO1_IRQ = 73 there):

[ 4.956] [t=0x000b76d3] ti.sysbios.family.c64p.Hwi: ERROR: line 511: E_handleNotFound: Hwi handle not found: 0x90110448
[ 4.956] ti.sysbios.family.c64p.Hwi: line 511: E_handleNotFound: Hwi handle not found: 0x90110448
[ 4.956] xdc.runtime.Error.raise: terminating execution

Any idea what I'm missing? I don't understand why BIOS is trying to delete a HWI. Many thanks in advance for any advice.