Subject: Re: [PATCH V10 net-next 07/10] net: hibmcge: Implement rx_poll function to receive packets

From: Jakub Kicinski <[email-masked]>
Date: Sun, 15 Sep 2024 17:18:45 +0200

On Thu, 12 Sep 2024 10:51:24 +0800 Jijie Shao wrote:
> +static int hbg_napi_rx_poll(struct napi_struct *napi, int budget)
> +{
> +	struct hbg_ring *ring = container_of(napi, struct hbg_ring, napi);
> +	struct hbg_priv *priv = ring->priv;
> +	struct hbg_rx_desc *rx_desc;
> +	struct hbg_buffer *buffer;
> +	u32 packet_done = 0;
> +	u32 pkt_len;
> +
> +	while (packet_done < budget) {
> +		if (unlikely(hbg_queue_is_empty(ring->ntc, ring->ntu, ring)))
> +			break;
> +
> +		buffer = &ring->queue[ring->ntc];
> +		if (unlikely(!buffer->skb))
> +			goto next_buffer;
> +
> +		if (unlikely(!hbg_sync_data_from_hw(priv, buffer)))
> +			break;
> +
> +		hbg_dma_unmap(buffer);
> +
> +		skb_reserve(buffer->skb, HBG_PACKET_HEAD_SIZE + NET_IP_ALIGN);
> +
> +		rx_desc = (struct hbg_rx_desc *)buffer->skb->data;
> +		pkt_len = FIELD_GET(HBG_RX_DESC_W2_PKT_LEN_M, rx_desc->word2);
> +		skb_put(buffer->skb, pkt_len);
> +		buffer->skb->protocol = eth_type_trans(buffer->skb, priv->netdev);
> +
> +		dev_sw_netstats_rx_add(priv->netdev, pkt_len);
> +		netif_receive_skb(buffer->skb);

why not napi_gro_receive() ?

> +		buffer->skb = NULL;
> +		hbg_rx_fill_one_buffer(priv);
> +
> +next_buffer:
> +		hbg_queue_move_next(ntc, ring);
> +		packet_done++;
> +	}
> +
> +	hbg_rx_fill_buffers(priv);

don't try to refill the buffers if budget is 0, if budget is 0 we
should only do Tx processing (IOW this function should do nothing)

> +	if (likely(napi_complete_done(napi, packet_done)))

same comment as on Tx, don't call if not done

> +		hbg_hw_irq_enable(priv, HBG_INT_MSK_RX_B, true);
> +
> +	return packet_done;
> +}