Re: [PATCH net-next v3 5/9] net: phy: micrel: add HW timestamp configuration reporting

[Kory Maincent <kory.maincent@bootlin.com>]

On Wed, 19 Nov 2025 12:47:21 +0000
Vadim Fedorenko <vadim.fedorenko@linux.dev> wrote:

> The driver stores HW timestamping configuration and can technically
> report it. Add callback to do it.
> 
> Signed-off-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
> ---
>  drivers/net/phy/micrel.c | 27 +++++++++++++++++++++++++++
>  1 file changed, 27 insertions(+)
> 
> diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
> index 05de68b9f719..b149d539aec3 100644
> --- a/drivers/net/phy/micrel.c
> +++ b/drivers/net/phy/micrel.c
> @@ -3147,6 +3147,18 @@ static void lan8814_flush_fifo(struct phy_device
> *phydev, bool egress) lanphy_read_page_reg(phydev, LAN8814_PAGE_PORT_REGS,
> PTP_TSU_INT_STS); }
>  
> +static int lan8814_hwtstamp_get(struct mii_timestamper *mii_ts,
> +				struct kernel_hwtstamp_config *config)
> +{
> +	struct kszphy_ptp_priv *ptp_priv =
> +			  container_of(mii_ts, struct kszphy_ptp_priv,
> mii_ts); +
> +	config->tx_type = ptp_priv->hwts_tx_type;
> +	config->rx_filter = ptp_priv->rx_filter;
> +
> +	return 0;
> +}
> +
>  static int lan8814_hwtstamp_set(struct mii_timestamper *mii_ts,
>  				struct kernel_hwtstamp_config *config,
>  				struct netlink_ext_ack *extack)
> @@ -4390,6 +4402,7 @@ static void lan8814_ptp_init(struct phy_device *phydev)
>  	ptp_priv->mii_ts.rxtstamp = lan8814_rxtstamp;
>  	ptp_priv->mii_ts.txtstamp = lan8814_txtstamp;
>  	ptp_priv->mii_ts.hwtstamp_set = lan8814_hwtstamp_set;
> +	ptp_priv->mii_ts.hwtstamp_get = lan8814_hwtstamp_get;
>  	ptp_priv->mii_ts.ts_info  = lan8814_ts_info;
>  
>  	phydev->mii_ts = &ptp_priv->mii_ts;
> @@ -5042,6 +5055,19 @@ static void lan8841_ptp_enable_processing(struct
> kszphy_ptp_priv *ptp_priv, #define LAN8841_PTP_TX_TIMESTAMP_EN
> 443 #define LAN8841_PTP_TX_MOD			445
>  
> +static int lan8841_hwtstamp_get(struct mii_timestamper *mii_ts,
> +				struct kernel_hwtstamp_config *config)
> +{
> +	struct kszphy_ptp_priv *ptp_priv;
> +
> +	ptp_priv = container_of(mii_ts, struct kszphy_ptp_priv, mii_ts);
> +
> +	config->tx_type = ptp_priv->hwts_tx_type;
> +	config->rx_filter = ptp_priv->rx_filter;

Something related to this patch, it seems there is an issue in the set
callback:
https://elixir.bootlin.com/linux/v6.18-rc6/source/drivers/net/phy/micrel.c#L3056

The priv->rx_filter and priv->hwts_tx_type are set before the switch condition.
The hwtstamp_get can then report something that is not supported.
Also HWTSTAMP_TX_ONESTEP_P2P is not managed by the driver but not returning
-ERANGE either so if we set this config the hwtstamp_get will report something
wrong as not supported.
I think you will need to add a new patch here to fix the hwtstamp_set ops.

Maybe we should update net_hwtstamp_validate to check on the capabilities
reported by ts_info but that is a bigger change.

> +
> +	return 0;
> +}
> +
>  static int lan8841_hwtstamp_set(struct mii_timestamper *mii_ts,
>  				struct kernel_hwtstamp_config *config,
>  				struct netlink_ext_ack *extack)
> @@ -5925,6 +5951,7 @@ static int lan8841_probe(struct phy_device *phydev)
>  	ptp_priv->mii_ts.rxtstamp = lan8841_rxtstamp;
>  	ptp_priv->mii_ts.txtstamp = lan8814_txtstamp;
>  	ptp_priv->mii_ts.hwtstamp_set = lan8841_hwtstamp_set;
> +	ptp_priv->mii_ts.hwtstamp_get = lan8841_hwtstamp_get;
>  	ptp_priv->mii_ts.ts_info = lan8841_ts_info;
>  
>  	phydev->mii_ts = &ptp_priv->mii_ts;



-- 
Köry Maincent, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com