Adding an Interrupt Handler

The driver must first obtain the iblock cookie to initialize mutexes used in the driver handler. Only after those mutexes have been initialized can the interrupt handler be added.

    i = ddi_get_iblock_cookie(dip, 0, &isp->iblock_cookie};
     if (i != DDI_SUCCESS) {
         do error recovery
            return (DDI_FAILURE);
     }

     mutex_init(&isp->mutex, "isp_mutex", MUTEX_DRIVER,
         (void *)isp->iblock_cookie);
     i = ddi_add_intr(dip, 0, &isp->iblock_cookie,
         0, isp_intr, (caddr_t)isp);
     if (i != DDI_SUCCESS) {
         do error recovery
            return (DDI_FAILURE);
     }

The driver should determine if a high-level interrupt handler is required. If a high-level handler is required and the driver is not coded to provide one, rewrite the driver to include either a high-level interrupt or fail the attach. See Handling High-Level Interrupts for a description of high-level interrupt handling.