Re: [PATCH net-next v20 07/13] rtase: Implement a function to receive packets

[Jakub Kicinski <kuba@kernel.org>]

On Fri, 7 Jun 2024 16:43:15 +0800 Justin Lai wrote:
> +static int rx_handler(struct rtase_ring *ring, int budget)
> +{
> +	const struct rtase_private *tp = ring->ivec->tp;
> +	union rtase_rx_desc *desc_base = ring->desc;
> +	u32 pkt_size, cur_rx, delta, entry, status;
> +	struct net_device *dev = tp->dev;
> +	union rtase_rx_desc *desc;
> +	struct sk_buff *skb;
> +	int workdone = 0;
> +
> +	cur_rx = ring->cur_idx;
> +	entry = cur_rx % RTASE_NUM_DESC;
> +	desc = &desc_base[entry];
> +
> +	do {
> +		/* make sure discriptor has been updated */
> +		rmb();

Barriers are between things. What is this barrier between?

> +		status = le32_to_cpu(desc->desc_status.opts1);
> +
> +		if (status & RTASE_DESC_OWN)
> +			break;