Hi Jakub,
On 29/07/23 5:54 am, Jakub Kicinski wrote:
> On Thu, 27 Jul 2023 16:58:23 +0530 MD Danish Anwar wrote:
>> +static int emac_tx_complete_packets(struct prueth_emac *emac, int chn,
>> + int budget)
>> +{
>> + struct net_device *ndev = emac->ndev;
>> + struct cppi5_host_desc_t *desc_tx;
>> + struct netdev_queue *netif_txq;
>> + struct prueth_tx_chn *tx_chn;
>> + unsigned int total_bytes = 0;
>> + struct sk_buff *skb;
>> + dma_addr_t desc_dma;
>> + int res, num_tx = 0;
>> + void **swdata;
>> +
>> + tx_chn = &emac->tx_chns[chn];
>> +
>> + while (budget) {
>> + res = k3_udma_glue_pop_tx_chn(tx_chn->tx_chn, &desc_dma);
>> + if (res == -ENODATA)
>> + break;
>
> You shouldn't limit the number of serviced packets to budget for Tx
> NAPI.
>
> https://docs.kernel.org/next/networking/napi.html#driver-api
>
>> + skb->dev = ndev;
>> + if (!netif_running(skb->dev)) {
>> + dev_kfree_skb_any(skb);
>> + return 0;
>> + }
>
> why do you check if the interface is running?
> If a packet arrives, it means the interface is running..
>
Sure, I will drop this if condition.
>> +drop_free_descs:
>> + prueth_xmit_free(tx_chn, first_desc);
>> +drop_stop_q:
>> + netif_tx_stop_queue(netif_txq);
>
> Do not stop the queue on DMA errors. If the queue is empty nothing
> will wake it up. Queue should only be stopped based on occupancy.
>
Sure, I will try to make sure we only stop queue based on occupancy.
>> + dev_kfree_skb_any(skb);
>> +
>> + /* error */
>> + ndev->stats.tx_dropped++;
>> + netdev_err(ndev, "tx: error: %d\n", ret);
>> +
>> + return ret;
--
Thanks and Regards,
Danish.
