Re: [PATCH v4 3/4] can: kvaser_usb: Add support for the Usbcan-II family

On Mon, Jan 12, 2015 at 07:07:41AM -0500, Ahmed S. Darwish wrote:

Hi Marc,

On Mon, Jan 12, 2015 at 12:43:56PM +0100, Marc Kleine-Budde wrote:

quoted

On 01/11/2015 09:36 PM, Ahmed S. Darwish wrote:

quoted

+
+	switch (dev->family) {
+	case KVASER_LEAF:
+		rx_msg = msg->u.leaf.rx_can.msg;
+		break;
+	case KVASER_USBCAN:
+		rx_msg = msg->u.usbcan.rx_can.msg;
+		break;
+	default:
+		dev_err(dev->udev->dev.parent,
+			"Invalid device family (%d)\n", dev->family);
 		return;

should not happen.

Yes, but otherwise I get GCC warnings of 'rx_msg' possibly
being unused. I can add __maybe_unused to rx_msg of course,
but such annotation may hide possible errors in the future.

Ah, what I meant is using uninitialized_var() to suppress the
GCC warning. But, really, using that macro has a bad history
of hiding errors in the future.

Kindly check http://lwn.net/Articles/529954/ for context.

Another solution might be initializing rx_msg to NULL.

quoted

quoted

+	switch (dev->family) {
+	case KVASER_LEAF:
+		msg_tx_can_flags = &msg->u.tx_can.leaf.flags;
+		break;
+	case KVASER_USBCAN:
+		msg_tx_can_flags = &msg->u.tx_can.usbcan.flags;
+		break;
+	default:
+		dev_err(dev->udev->dev.parent,
+			"Invalid device family (%d)\n", dev->family);
+		goto releasebuf;

should not happen, please remove

Like the 'rx_msg' case above.

Thanks,
Darwish