Use the dev->read_subdev that was setup in the device attach instead
of accessing the dev->subdevices array directly.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 static irqreturn_t pc236_interrupt(int irq, void *d)
 {
        struct comedi_device *dev = d;
-       struct comedi_subdevice *s = &dev->subdevices[1];
+       struct comedi_subdevice *s = dev->read_subdev;
        int handled;
 
        handled = pc236_intr_check(dev);