Re: [PATCH 09/10] dpaa_eth: add support for hardware timestamping

From: Richard Cochran
Date: Mon Jun 04 2018 - 09:49:31 EST


On Mon, Jun 04, 2018 at 03:08:36PM +0800, Yangbo Lu wrote:

> +if FSL_DPAA_ETH
> +config FSL_DPAA_ETH_TS
> + bool "DPAA hardware timestamping support"
> + select PTP_1588_CLOCK_QORIQ
> + default n
> + help
> + Enable DPAA hardware timestamping support.
> + This option is useful for applications to get
> + hardware time stamps on the Ethernet packets
> + using the SO_TIMESTAMPING API.
> +endif

You should drop this #ifdef. In general, if a MAC supports time
stamping and PHC, then the driver support should simply be compiled
in.

[ When time stamping incurs a large run time performance penalty to
non-PTP users, then it might make sense to have a Kconfig option to
disable it, but that doesn't appear to be the case here. ]

> @@ -1615,6 +1635,24 @@ static int dpaa_eth_refill_bpools(struct dpaa_priv *priv)
> skbh = (struct sk_buff **)phys_to_virt(addr);
> skb = *skbh;
>
> +#ifdef CONFIG_FSL_DPAA_ETH_TS
> + if (priv->tx_tstamp &&
> + skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP) {

This condition fits on one line easily.

> + struct skb_shared_hwtstamps shhwtstamps;
> + u64 ns;

Local variables belong at the top of the function.

> + memset(&shhwtstamps, 0, sizeof(shhwtstamps));
> +
> + if (!dpaa_get_tstamp_ns(priv->net_dev, &ns,
> + priv->mac_dev->port[TX],
> + (void *)skbh)) {
> + shhwtstamps.hwtstamp = ns_to_ktime(ns);
> + skb_tstamp_tx(skb, &shhwtstamps);
> + } else {
> + dev_warn(dev, "dpaa_get_tstamp_ns failed!\n");
> + }
> + }
> +#endif
> if (unlikely(qm_fd_get_format(fd) == qm_fd_sg)) {
> nr_frags = skb_shinfo(skb)->nr_frags;
> dma_unmap_single(dev, addr, qm_fd_get_offset(fd) +
> @@ -2086,6 +2124,14 @@ static int dpaa_start_xmit(struct sk_buff *skb, struct net_device *net_dev)
> if (unlikely(err < 0))
> goto skb_to_fd_failed;
>
> +#ifdef CONFIG_FSL_DPAA_ETH_TS
> + if (priv->tx_tstamp &&
> + skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP) {

One line please.

> + fd.cmd |= FM_FD_CMD_UPD;
> + skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
> + }
> +#endif
> +
> if (likely(dpaa_xmit(priv, percpu_stats, queue_mapping, &fd) == 0))
> return NETDEV_TX_OK;
>

Thanks,
Richard