Subject: Re: [PATCH net v2 1/2] net: micrel: Fix PTP frame parsing for lan8814

From: Simon Horman <[email-masked]>
Date: Fri, 19 Jan 2024 20:01:48 +0000

On Thu, Jan 18, 2024 at 09:59:15AM +0100, Horatiu Vultur wrote:
> The HW has the capability to check each frame if it is a PTP frame,
> which domain it is, which ptp frame type it is, different ip address in
> the frame. And if one of these checks fail then the frame is not
> timestamp. Most of these checks were disabled except checking the field
> minorVersionPTP inside the PTP header. Meaning that once a partner sends
> a frame compliant to 8021AS which has minorVersionPTP set to 1, then the
> frame was not timestamp because the HW expected by default a value of 0
> in minorVersionPTP. This is exactly the same issue as on lan8841.
> Fix this issue by removing this check so the userspace can decide on this.
> 
> Fixes: ece19502834d ("net: phy: micrel: 1588 support for LAN8814 phy")
> Signed-off-by: Horatiu Vultur <[email-masked]>
> Reviewed-by: Maxime Chevallier <[email-masked]>
> Reviewed-by: Divya Koppera <[email-masked]>
> ---
>  drivers/net/phy/micrel.c | 11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
> index bf4053431dcb3..43520ac0f4e00 100644
> --- a/drivers/net/phy/micrel.c
> +++ b/drivers/net/phy/micrel.c
> @@ -120,6 +120,11 @@
>   */
>  #define LAN8814_1PPM_FORMAT			17179
>  
> +#define PTP_RX_VERSION				0x0248
> +#define PTP_TX_VERSION				0x0288
> +#define PTP_MAX_VERSION(x)			(((x) & GENMASK(7, 0)) << 8)
> +#define PTP_MIN_VERSION(x)			((x) & GENMASK(7, 0))

FWIIW, these macros feel like open-coded versions of FIELD_PREP to me.

> +
>  #define PTP_RX_MOD				0x024F
>  #define PTP_RX_MOD_BAD_UDPV4_CHKSUM_FORCE_FCS_DIS_ BIT(3)
>  #define PTP_RX_TIMESTAMP_EN			0x024D
> @@ -3150,6 +3155,12 @@ static void lan8814_ptp_init(struct phy_device *phydev)
>  	lanphy_write_page_reg(phydev, 5, PTP_TX_PARSE_IP_ADDR_EN, 0);
>  	lanphy_write_page_reg(phydev, 5, PTP_RX_PARSE_IP_ADDR_EN, 0);
>  
> +	/* Disable checking for minorVersionPTP field */
> +	lanphy_write_page_reg(phydev, 5, PTP_RX_VERSION,
> +			      PTP_MAX_VERSION(0xff) | PTP_MIN_VERSION(0x0));
> +	lanphy_write_page_reg(phydev, 5, PTP_TX_VERSION,
> +			      PTP_MAX_VERSION(0xff) | PTP_MIN_VERSION(0x0));
> +
>  	skb_queue_head_init(&ptp_priv->tx_queue);
>  	skb_queue_head_init(&ptp_priv->rx_queue);
>  	INIT_LIST_HEAD(&ptp_priv->rx_ts_list);
> -- 
> 2.34.1
>