On 20.12.21 12:19, Johan Hovold wrote:

+static int gnss_usb_probe(struct usb_interface *intf, const struct usb_device_id *id)
+{
+	struct usb_device *udev = interface_to_usbdev(intf);
+	struct usb_endpoint_descriptor *in, *out;
+	struct gnss_device *gdev;
+	struct gnss_usb *gusb;
+	struct urb *urb;
+	size_t buf_len;
+	void *buf;
+	int ret;
+
+	ret = usb_find_common_endpoints(intf->cur_altsetting, &in, &out, NULL,
+			NULL);
+	if (ret)
+		return ret;
+
+	gusb = kzalloc(sizeof(*gusb), GFP_KERNEL);
+	if (!gusb)
+		return -ENOMEM;
+
+	gdev = gnss_allocate_device(&intf->dev);
+	if (!gdev) {
+		ret = -ENOMEM;
+		goto err_free_gusb;
+	}
+
+	gdev->ops = &gnss_usb_gnss_ops;
+	gdev->type = GNSS_TYPE_NMEA;
+	gnss_set_drvdata(gdev, gusb);
+
+	urb = usb_alloc_urb(0, GFP_KERNEL);
+	if (!urb)
+			goto err_put_gdev;

The value of 'ret' here is the result of
usb_find_common_endpoints(), hence 0 due to the prior test.

+
+	buf_len = max(usb_endpoint_maxp(in), GNSS_USB_READ_BUF_LEN);
+
+	buf = kzalloc(buf_len, GFP_KERNEL);
+	if (!buf)
+		goto err_free_urb;
+
+	usb_fill_bulk_urb(urb, udev,
+			usb_rcvbulkpipe(udev, usb_endpoint_num(in)),
+			buf, buf_len, gnss_usb_rx_complete, gusb);
+
+	gusb->intf = intf;
+	gusb->udev = udev;
+	gusb->gdev = gdev;
+	gusb->read_urb = urb;
+	gusb->write_pipe = usb_sndbulkpipe(udev, usb_endpoint_num(out));
+
+	ret = gnss_register_device(gdev);
+	if (ret)
+		goto err_free_buf;
+
+	usb_set_intfdata(intf, gusb);
+
+	return 0;
+
+err_free_buf:
+	kfree(buf);
+err_free_urb:
+	usb_free_urb(urb);
+err_put_gdev:
+	gnss_put_device(gdev);
+err_free_gusb:
+	kfree(gusb);
+
+	return ret;

Yet you return it in the error case and subsequent error cases..

    HTH
        Oliver