On Mon, 7 Aug 2023 11:21:49 +0530 Radhey Shyam Pandey wrote:
> +struct axi_skbuff {
> + struct scatterlist sgl[MAX_SKB_FRAGS + 1];
> + struct dma_async_tx_descriptor *desc;
> + dma_addr_t dma_address;
> + struct sk_buff *skb;
> + struct list_head lh;
> + int sg_len;
> +} __packed;
Why __packed?
> +static netdev_tx_t
> +axienet_start_xmit_dmaengine(struct sk_buff *skb, struct net_device *ndev)
> +{
> + struct dma_async_tx_descriptor *dma_tx_desc = NULL;
> + struct axienet_local *lp = netdev_priv(ndev);
> + u32 app[DMA_NUM_APP_WORDS] = {0};
> + struct axi_skbuff *axi_skb;
> + u32 csum_start_off;
> + u32 csum_index_off;
> + int sg_len;
> + int ret;
> +
> + sg_len = skb_shinfo(skb)->nr_frags + 1;
> + axi_skb = kmem_cache_zalloc(lp->skb_cache, GFP_KERNEL);
> + if (!axi_skb)
> + return NETDEV_TX_BUSY;
Drop on error, you're not stopping the queue correctly, just drop,
return OK and avoid bugs.
> +static inline int axienet_init_dmaengine(struct net_device *ndev)
Why inline? Please remove the spurious inline annotations.
> +{
> + struct axienet_local *lp = netdev_priv(ndev);
> + int i, ret;
> +
> + lp->tx_chan = dma_request_chan(lp->dev, "tx_chan0");
> + if (IS_ERR(lp->tx_chan)) {
> + ret = PTR_ERR(lp->tx_chan);
> + return dev_err_probe(lp->dev, ret, "No Ethernet DMA (TX) channel found\n");
> + }
> +
> + lp->rx_chan = dma_request_chan(lp->dev, "rx_chan0");
> + if (IS_ERR(lp->rx_chan)) {
> + ret = PTR_ERR(lp->rx_chan);
> + dev_err_probe(lp->dev, ret, "No Ethernet DMA (RX) channel found\n");
> + goto err_dma_request_rx;
name labels after the target, not the source. Makes it a ton easier
to maintain sanity when changing the code later.
> + }
> +
> + lp->skb_cache = kmem_cache_create("ethernet", sizeof(struct axi_skbuff),
> + 0, 0, NULL);
Why create a cache ?
Isn't it cleaner to create a fake ring buffer of sgl? Most packets will
not have MAX_SKB_FRAGS of memory. On a ring buffer you can use only as
many sg entries as the packet requires. Also no need to alloc/free.
> + if (!lp->skb_cache) {
> + ret = -ENOMEM;
double space, please fix everywhere
> + goto err_kmem;
> @@ -2140,6 +2432,31 @@ static int axienet_probe(struct platform_device *pdev)
> }
> netif_napi_add(ndev, &lp->napi_rx, axienet_rx_poll);
> netif_napi_add(ndev, &lp->napi_tx, axienet_tx_poll);
> + } else {
> + struct xilinx_vdma_config cfg;
> + struct dma_chan *tx_chan;
> +
> + lp->eth_irq = platform_get_irq_optional(pdev, 0);
This can't fail?
> + tx_chan = dma_request_chan(lp->dev, "tx_chan0");
> +
> + if (IS_ERR(tx_chan)) {
no empty lines between call and its error check, please fix thru out
> + ret = PTR_ERR(tx_chan);
> + dev_err_probe(lp->dev, ret, "No Ethernet DMA (TX) channel found\n");
> + goto cleanup_clk;
> + }
--
pw-bot: cr
