Re: [PATCH net] cdc_ether: Fix handling connection notification

From: BjÃrn Mork
Date: Wed Nov 30 2016 - 16:51:29 EST


Kristian Evensen <kristian.evensen@xxxxxxxxx> writes:

> +void usbnet_cdc_zte_status(struct usbnet *dev, struct urb *urb)
> +{
> + struct usb_cdc_notification *event;
> +
> + if (urb->actual_length < sizeof(*event))
> + return;
> +
> + event = urb->transfer_buffer;
> +
> + if (event->bNotificationType != USB_CDC_NOTIFY_NETWORK_CONNECTION) {
> + usbnet_cdc_status(dev, urb);
> + return;
> + }
> +
> + netif_dbg(dev, timer, dev->net, "CDC: carrier %s\n",
> + event->wValue ? "on" : "off");
> +
> + if (event->wValue &&
> + !test_bit(__LINK_STATE_NOCARRIER, &dev->net->state))
> + usbnet_link_change(dev, 0, 0);
> +
> + usbnet_link_change(dev, !!event->wValue, 0);
> +}

As Henning said: Use netif_carrier_ok instead of open coding it.

But I also think you need to replace the first usbnet_link_change() with
a plain netif_carrier_off(dev->net). Calling usbnet_link_change() twice
here is only going to set off the "kevent XX may have been dropped"
message since you call schedule_work() twice without giving the work
queue a chance to be processed. No need to do that.


BjÃrn