Re: [PATCH RFC net-next v20] vmxnet3: Add XDP support.

[Simon Horman <simon.horman@corigine.com>]

On Wed, Apr 12, 2023 at 04:44:34PM -0700, William Tu wrote:
> From: William Tu <u9012063@gmail.com>
> 
> The patch adds native-mode XDP support: XDP DROP, PASS, TX, and REDIRECT.

...

> +/* ndo_xdp_xmit */
> +int
> +vmxnet3_xdp_xmit(struct net_device *dev,
> +		 int n, struct xdp_frame **frames, u32 flags)
> +{
> +	struct vmxnet3_adapter *adapter = netdev_priv(dev);
> +	struct vmxnet3_tx_queue *tq;
> +	struct netdev_queue *nq;
> +	int i;
> +
> +	if (unlikely(test_bit(VMXNET3_STATE_BIT_QUIESCED, &adapter->state)))
> +		return -ENETDOWN;
> +	if (unlikely(test_bit(VMXNET3_STATE_BIT_RESETTING, &adapter->state)))
> +		return -EINVAL;
> +
> +	tq = vmxnet3_xdp_get_tq(adapter);
> +	if (tq->stopped)
> +		return -ENETDOWN;
> +
> +	nq = netdev_get_tx_queue(adapter->netdev, tq->qid);

Hi William,

gcc-12 with W=1 tells me that:

 drivers/net/vmxnet3/vmxnet3_xdp.c:228:23: warning: variable 'nq' set but not used [-Wunused-but-set-variable]
         struct netdev_queue *nq;

> +
> +	for (i = 0; i < n; i++) {
> +		if (vmxnet3_xdp_xmit_frame(adapter, frames[i], tq, true)) {
> +			tq->stats.xdp_xmit_err++;
> +			break;
> +		}
> +	}
> +	tq->stats.xdp_xmit += i;
> +
> +	return i;
> +}

...