Re: [RFC PATCH 06/10] net: ti: prueth: Adds HW timestamping support for PTP using PRU-ICSS IEP module

Richard Cochran
2025-01-11T16:35:22Z

On Fri, Jan 10, 2025 at 11:29:02AM +0530, Basharath Hussain Khaja wrote:

> @@ -189,12 +190,37 @@ static void icssm_emac_get_regs(struct net_device *ndev,
> regs->version = PRUETH_REG_DUMP_GET_VER(prueth);
> }
>
> +static int icssm_emac_get_ts_info(struct net_device *ndev,
> + struct kernel_ethtool_ts_info *info)
> +{
> + struct prueth_emac *emac = netdev_priv(ndev);
> +
> + if ((PRUETH_IS_EMAC(emac->prueth) && !emac->emac_ptp_tx_irq))
> + return ethtool_op_get_ts_info(ndev, info);
> +
> + info->so_timestamping =
> + SOF_TIMESTAMPING_TX_HARDWARE |
> + SOF_TIMESTAMPING_TX_SOFTWARE |

The driver advertises software Transmit time stamping, but where is
the call to skb_tx_timestamp() ?

I didn't see it in Patch #4.

> + SOF_TIMESTAMPING_RX_HARDWARE |
> + SOF_TIMESTAMPING_RX_SOFTWARE |
> + SOF_TIMESTAMPING_SOFTWARE |
> + SOF_TIMESTAMPING_RAW_HARDWARE;
> +
> + info->phc_index = icss_iep_get_ptp_clock_idx(emac->prueth->iep);
> + info->tx_types = BIT(HWTSTAMP_TX_OFF) | BIT(HWTSTAMP_TX_ON);
> + info->rx_filters = BIT(HWTSTAMP_FILTER_NONE) |
> + BIT(HWTSTAMP_FILTER_PTP_V2_EVENT);
> +
> + return 0;
> +}

> @@ -442,6 +482,173 @@ static void icssm_emac_adjust_link(struct net_device *ndev)
> spin_unlock_irqrestore(&emac->lock, flags);
> }
>
> +static u8 icssm_prueth_ptp_ts_event_type(struct sk_buff *skb, u8 *ptp_msgtype)
> +{
> + unsigned int ptp_class = ptp_classify_raw(skb);
> + struct ptp_header *hdr;
> + u8 msgtype, event_type;
> +
> + if (ptp_class == PTP_CLASS_NONE)
> + return PRUETH_PTP_TS_EVENTS;
> +
> + hdr = ptp_parse_header(skb, ptp_class);
> + if (!hdr)
> + return PRUETH_PTP_TS_EVENTS;
> +
> + msgtype = ptp_get_msgtype(hdr, ptp_class);
> + /* Treat E2E Delay Req/Resp messages sane as P2P peer delay req/resp

s/sane/in the same way/

> + * in driver here since firmware stores timestamps in the same memory
> + * location for either (since they cannot operate simultaneously
> + * anyway)
> + */
> + switch (msgtype) {
> + case PTP_MSGTYPE_SYNC:
> + event_type = PRUETH_PTP_SYNC;
> + break;
> + case PTP_MSGTYPE_DELAY_REQ:
> + case PTP_MSGTYPE_PDELAY_REQ:
> + event_type = PRUETH_PTP_DLY_REQ;
> + break;
> + /* TODO: Check why PTP_MSGTYPE_DELAY_RESP needs timestamp
> + * and need for it.
> + */
> + case 0x9:

Delay response messages are PTP "general" messages and not event
messages, and as such they do not require time stamps.

> + case PTP_MSGTYPE_PDELAY_RESP:
> + event_type = PRUETH_PTP_DLY_RESP;
> + break;
> + default:
> + event_type = PRUETH_PTP_TS_EVENTS;
> + }
> +
> + if (ptp_msgtype)
> + *ptp_msgtype = msgtype;
> +
> + return event_type;
> +}

Thanks,
Richard