staging: comedi: dt9812: do not allow attaching to unsupported devices

The DT9812 is part of the ECONseries of USB Data Acquisition Modules.
This driver only supports the DT9812-10V and DT9812-2.5V versions of
the module. Do not attach to the device if an unsupported module is
detected.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/dt9812.c

@@ -768,6 +768,12 @@ static int dt9812_reset_device(struct comedi_device *dev)
 	dev_info(dev->class_dev, "USB DT9812 (%4.4x.%4.4x.%4.4x) #0x%8.8x\n",
 		 vendor, product, devpriv->device, serial);
 
+	if (devpriv->device != DT9812_DEVID_DT9812_10 &&
+	    devpriv->device != DT9812_DEVID_DT9812_2PT5) {
+		dev_err(dev->class_dev, "Unsupported device!\n");
+		return -EINVAL;
+	}
+
 	return 0;
 }