2024-04-17 16:55:15

by Oleksij Rempel

[permalink] [raw]
Subject: [PATCH net-next v1 4/4] net: stmmac: use delays reported by the PHY driver to correct MAC propagation delay

Now after PHY drivers are able to report data path delays, we can use
them in the MAC drivers for the delay correction.

Signed-off-by: Oleksij Rempel <[email protected]>
---
drivers/net/ethernet/stmicro/stmmac/stmmac.h | 2 ++
.../ethernet/stmicro/stmmac/stmmac_hwtstamp.c | 4 ++++
.../net/ethernet/stmicro/stmmac/stmmac_main.c | 17 ++++++++++++++++-
3 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
index dddcaa9220cc3..6db54ce33ea72 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
@@ -288,6 +288,8 @@ struct stmmac_priv {
u32 sub_second_inc;
u32 systime_flags;
u32 adv_ts;
+ u64 phy_tx_delay_ns;
+ u64 phy_rx_delay_ns;
int use_riwt;
int irq_wake;
rwlock_t ptp_lock;
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c
index f05bd757dfe52..bbf284cb7cc2a 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c
@@ -71,6 +71,8 @@ static void hwtstamp_correct_latency(struct stmmac_priv *priv)
/* MAC-internal ingress latency */
scaled_ns = readl(ioaddr + PTP_TS_INGR_LAT);

+ scaled_ns += priv->phy_rx_delay_ns << 16;
+
/* See section 11.7.2.5.3.1 "Ingress Correction" on page 4001 of
* i.MX8MP Applications Processor Reference Manual Rev. 1, 06/2021
*/
@@ -95,6 +97,8 @@ static void hwtstamp_correct_latency(struct stmmac_priv *priv)
/* MAC-internal egress latency */
scaled_ns = readl(ioaddr + PTP_TS_EGR_LAT);

+ scaled_ns += priv->phy_tx_delay_ns << 16;
+
reg_tsec = scaled_ns >> 16;
reg_tsecsns = scaled_ns & 0xff00;

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index fe3498e86de9d..30c7c278b7062 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -1097,8 +1097,23 @@ static void stmmac_mac_link_up(struct phylink_config *config,
if (priv->dma_cap.fpesel)
stmmac_fpe_link_state_handle(priv, true);

- if (priv->plat->flags & STMMAC_FLAG_HWTSTAMP_CORRECT_LATENCY)
+ if (priv->plat->flags & STMMAC_FLAG_HWTSTAMP_CORRECT_LATENCY) {
+ int ret = 0;
+
+ if (phy)
+ ret = phy_get_timesync_data_path_delays(phy,
+ &priv->phy_tx_delay_ns,
+ &priv->phy_rx_delay_ns);
+ if (!phy || ret) {
+ if (ret != -EOPNOTSUPP)
+ netdev_err(priv->dev, "Failed to get PHY delay: %pe\n",
+ ERR_PTR(ret));
+ priv->phy_tx_delay_ns = 0;
+ priv->phy_rx_delay_ns = 0;
+ }
+
stmmac_hwtstamp_correct_latency(priv, priv);
+ }
}

static const struct phylink_mac_ops stmmac_phylink_mac_ops = {
--
2.39.2



2024-04-17 19:13:54

by Serge Semin

[permalink] [raw]
Subject: Re: [PATCH net-next v1 4/4] net: stmmac: use delays reported by the PHY driver to correct MAC propagation delay

On Wed, Apr 17, 2024 at 06:43:16PM +0200, Oleksij Rempel wrote:
> Now after PHY drivers are able to report data path delays, we can use
> them in the MAC drivers for the delay correction.
>
> Signed-off-by: Oleksij Rempel <[email protected]>
> ---
> drivers/net/ethernet/stmicro/stmmac/stmmac.h | 2 ++
> .../ethernet/stmicro/stmmac/stmmac_hwtstamp.c | 4 ++++
> .../net/ethernet/stmicro/stmmac/stmmac_main.c | 17 ++++++++++++++++-
> 3 files changed, 22 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
> index dddcaa9220cc3..6db54ce33ea72 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
> @@ -288,6 +288,8 @@ struct stmmac_priv {
> u32 sub_second_inc;
> u32 systime_flags;
> u32 adv_ts;

> + u64 phy_tx_delay_ns;
> + u64 phy_rx_delay_ns;

What's the point in adding these fields to the private data if you
retrieve the delays and use them in a single place? Just extend the
stmmac_hwtstamp_correct_latency() arguments list and pass the delays
as the function parameters.

-Serge(y)

> int use_riwt;
> int irq_wake;
> rwlock_t ptp_lock;
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c
> index f05bd757dfe52..bbf284cb7cc2a 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c
> @@ -71,6 +71,8 @@ static void hwtstamp_correct_latency(struct stmmac_priv *priv)
> /* MAC-internal ingress latency */
> scaled_ns = readl(ioaddr + PTP_TS_INGR_LAT);
>
> + scaled_ns += priv->phy_rx_delay_ns << 16;
> +
> /* See section 11.7.2.5.3.1 "Ingress Correction" on page 4001 of
> * i.MX8MP Applications Processor Reference Manual Rev. 1, 06/2021
> */
> @@ -95,6 +97,8 @@ static void hwtstamp_correct_latency(struct stmmac_priv *priv)
> /* MAC-internal egress latency */
> scaled_ns = readl(ioaddr + PTP_TS_EGR_LAT);
>
> + scaled_ns += priv->phy_tx_delay_ns << 16;
> +
> reg_tsec = scaled_ns >> 16;
> reg_tsecsns = scaled_ns & 0xff00;
>
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> index fe3498e86de9d..30c7c278b7062 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> @@ -1097,8 +1097,23 @@ static void stmmac_mac_link_up(struct phylink_config *config,
> if (priv->dma_cap.fpesel)
> stmmac_fpe_link_state_handle(priv, true);
>
> - if (priv->plat->flags & STMMAC_FLAG_HWTSTAMP_CORRECT_LATENCY)
> + if (priv->plat->flags & STMMAC_FLAG_HWTSTAMP_CORRECT_LATENCY) {
> + int ret = 0;
> +
> + if (phy)
> + ret = phy_get_timesync_data_path_delays(phy,
> + &priv->phy_tx_delay_ns,
> + &priv->phy_rx_delay_ns);
> + if (!phy || ret) {
> + if (ret != -EOPNOTSUPP)
> + netdev_err(priv->dev, "Failed to get PHY delay: %pe\n",
> + ERR_PTR(ret));
> + priv->phy_tx_delay_ns = 0;
> + priv->phy_rx_delay_ns = 0;
> + }
> +
> stmmac_hwtstamp_correct_latency(priv, priv);
> + }
> }
>
> static const struct phylink_mac_ops stmmac_phylink_mac_ops = {
> --
> 2.39.2
>
>