rem: bool check_service_req( ide_device_info *device )
add: check_service_req(ide_device_info *device)
context: bool check_service_req( ide_device_info *device ){	ide_bus_info *bus = device->bus;	int status;	// fast bailout if there is no request pending		if( device->num_running_reqs == 0 )		return false;	if( bus->active_device != device ) {		// don't apply any precautions in terms of IRQ		// -> the bus is in accessing state, so IRQs are ignored anyway		if( bus->controller->write_command_block_regs( bus->channel, 			&device->tf, ide_mask_device_head ) != B_OK )			// on error, pretend that this device asks for service			// -> the disappeared controller will be recognized soon ;)			return true;					bus->active_device = device;			// give one clock (400 ns) to take notice		spin( 1 );	}			status = bus->controller->get_altstatus( bus->channel );		return (status & ide_status_service) != 0;}