[PATCH net-next 0/3] net: dsa: add support for phylink managed EEE

[PATCH net-next 0/3] net: dsa: add support for phylink managed EEE

[Russell King (Oracle)]

Hi,

This series adds support for phylink managed EEE to DSA, and converts
mt753x to make use of this feature.

Patch 1 implements a helper to indicate whether the MAC LPI operations
are populated (suggested by Vladimir)

Patch 2 makes the necessary changes to the core code - we retain calling
set_mac_eee(), but this method now becomes a way to merely validate the
arguments when using phylink managed EEE rather than performing any
configuration.

Patch 3 converts the mt7530 driver to use phylink managed EEE.

 drivers/net/dsa/mt7530.c  | 69 ++++++++++++++++++++++++++++++++---------------
 drivers/net/phy/phylink.c |  3 +--
 include/linux/phylink.h   | 12 +++++++++
 net/dsa/user.c            | 21 +++++++++------
 4 files changed, 74 insertions(+), 31 deletions(-)

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
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[PATCH net-next 1/3] net: phylink: provide phylink_mac_implements_lpi()

[Russell King (Oracle)]

Provide a helper to determine whether the MAC operations structure
implements the LPI operations, which will be used by both phylink and
DSA.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
---
 drivers/net/phy/phylink.c |  3 +--
 include/linux/phylink.h   | 12 ++++++++++++
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
index 214b62fba991..6fbb5fd5b400 100644
--- a/drivers/net/phy/phylink.c
+++ b/drivers/net/phy/phylink.c
@@ -1957,8 +1957,7 @@ struct phylink *phylink_create(struct phylink_config *config,
 		return ERR_PTR(-EINVAL);
 	}
 
-	pl->mac_supports_eee_ops = mac_ops->mac_disable_tx_lpi &&
-				   mac_ops->mac_enable_tx_lpi;
+	pl->mac_supports_eee_ops = phylink_mac_implements_lpi(mac_ops);
 	pl->mac_supports_eee = pl->mac_supports_eee_ops &&
 			       pl->config->lpi_capabilities &&
 			       !phy_interface_empty(pl->config->lpi_interfaces);
diff --git a/include/linux/phylink.h b/include/linux/phylink.h
index 898b00451bbf..0de78673172d 100644
--- a/include/linux/phylink.h
+++ b/include/linux/phylink.h
@@ -737,6 +737,18 @@ static inline int phylink_get_link_timer_ns(phy_interface_t interface)
 	}
 }
 
+/**
+ * phylink_mac_implements_lpi() - determine if MAC implements LPI ops
+ * @ops: phylink_mac_ops structure
+ *
+ * Returns true if the phylink MAC operations structure indicates that the
+ * LPI operations have been implemented, false otherwise.
+ */
+static inline bool phylink_mac_implements_lpi(const struct phylink_mac_ops *ops)
+{
+	return ops && ops->mac_disable_tx_lpi && ops->mac_enable_tx_lpi;
+}
+
 void phylink_mii_c22_pcs_decode_state(struct phylink_link_state *state,
 				      unsigned int neg_mode, u16 bmsr, u16 lpa);
 void phylink_mii_c22_pcs_get_state(struct mdio_device *pcs,
-- 
2.30.2

[PATCH net-next 2/3] net: dsa: allow use of phylink managed EEE support

[Russell King (Oracle)]

In order to allow DSA drivers to use phylink managed EEE, changes are
necessary to the DSA .set_eee() and .get_eee() methods. Where drivers
make use of phylink managed EEE, these should just pass the method on
to their phylink implementation without calling the DSA specific
operations.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
---
 net/dsa/user.c | 21 +++++++++++++--------
 1 file changed, 13 insertions(+), 8 deletions(-)

diff --git a/net/dsa/user.c b/net/dsa/user.c
index 291ab1b4acc4..2e0a51c1b750 100644
--- a/net/dsa/user.c
+++ b/net/dsa/user.c
@@ -1243,16 +1243,21 @@ static int dsa_user_set_eee(struct net_device *dev, struct ethtool_keee *e)
 	if (!ds->ops->support_eee || !ds->ops->support_eee(ds, dp->index))
 		return -EOPNOTSUPP;
 
-	/* Port's PHY and MAC both need to be EEE capable */
-	if (!dev->phydev)
-		return -ENODEV;
+	/* If the port is using phylink managed EEE, then get_mac_eee is
+	 * unnecessary.
+	 */
+	if (!phylink_mac_implements_lpi(ds->phylink_mac_ops)) {
+		/* Port's PHY and MAC both need to be EEE capable */
+		if (!dev->phydev)
+			return -ENODEV;
 
-	if (!ds->ops->set_mac_eee)
-		return -EOPNOTSUPP;
+		if (!ds->ops->set_mac_eee)
+			return -EOPNOTSUPP;
 
-	ret = ds->ops->set_mac_eee(ds, dp->index, e);
-	if (ret)
-		return ret;
+		ret = ds->ops->set_mac_eee(ds, dp->index, e);
+		if (ret)
+			return ret;
+	}
 
 	return phylink_ethtool_set_eee(dp->pl, e);
 }
-- 
2.30.2

[PATCH net-next 3/3] net: dsa: mt7530: convert to phylink managed EEE

[Russell King (Oracle)]

Fixme: doesn't bit 25 and 26 also need to be set in the PMCR for
PMCR_FORCE_EEE100 and PMCR_FORCE_EEE1G to take effect?

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
---
 drivers/net/dsa/mt7530.c | 69 ++++++++++++++++++++++++++++------------
 1 file changed, 48 insertions(+), 21 deletions(-)

diff --git a/drivers/net/dsa/mt7530.c b/drivers/net/dsa/mt7530.c
index 1c83af805209..24191c4d5221 100644
--- a/drivers/net/dsa/mt7530.c
+++ b/drivers/net/dsa/mt7530.c
@@ -2957,28 +2957,62 @@ static void mt753x_phylink_mac_link_up(struct phylink_config *config,
 			mcr |= PMCR_FORCE_RX_FC_EN;
 	}
 
-	if (mode == MLO_AN_PHY && phydev && phy_init_eee(phydev, false) >= 0) {
-		switch (speed) {
-		case SPEED_1000:
-		case SPEED_2500:
-			mcr |= PMCR_FORCE_EEE1G;
-			break;
-		case SPEED_100:
-			mcr |= PMCR_FORCE_EEE100;
-			break;
-		}
-	}
-
 	mt7530_set(priv, MT753X_PMCR_P(dp->index), mcr);
 }
 
+static void mt753x_phylink_mac_disable_tx_lpi(struct phylink_config *config)
+{
+	struct dsa_port *dp = dsa_phylink_to_port(config);
+	struct mt7530_priv *priv = dp->ds->priv;
+
+	mt7530_clear(priv, MT753X_PMCR_P(dp->index),
+		     PMCR_FORCE_EEE1G | PMCR_FORCE_EEE100);
+}
+
+static int mt753x_phylink_mac_enable_tx_lpi(struct phylink_config *config,
+					    u32 timer, bool tx_clock_stop)
+{
+	struct dsa_port *dp = dsa_phylink_to_port(config);
+	struct mt7530_priv *priv = dp->ds->priv;
+	u32 val;
+
+	/* If the timer is zero, then set LPI_MODE_EN, which allows the
+	 * system to enter LPI mode immediately rather than waiting for
+	 * the LPI threshold.
+	 */
+	if (!timer)
+		val = LPI_MODE_EN;
+	else if (FIELD_FIT(LPI_THRESH_MASK, timer))
+		val = FIELD_PREP(LPI_THRESH_MASK, timer);
+	else
+		val = LPI_THRESH_MASK;
+
+	mt7530_rmw(priv, MT753X_PMEEECR_P(dp->index),
+		   LPI_THRESH_MASK | LPI_MODE_EN, val);
+
+	mt7530_set(priv, MT753X_PMCR_P(dp->index),
+		   PMCR_FORCE_EEE1G | PMCR_FORCE_EEE100);
+
+	return 0;
+}
+
 static void mt753x_phylink_get_caps(struct dsa_switch *ds, int port,
 				    struct phylink_config *config)
 {
 	struct mt7530_priv *priv = ds->priv;
+	u32 eeecr;
 
 	config->mac_capabilities = MAC_ASYM_PAUSE | MAC_SYM_PAUSE;
 
+	config->lpi_capabilities = MAC_100FD | MAC_1000FD | MAC_2500FD;
+	config->lpi_timer_limit_us = FIELD_MAX(LPI_THRESH_MASK);
+
+	eeecr = mt7530_read(priv, MT753X_PMEEECR_P(port));
+	/* tx_lpi_timer should be in microseconds. The time units for
+	 * LPI threshold are unspecified.
+	 */
+	config->lpi_timer_default = FIELD_GET(LPI_THRESH_MASK, eeecr);
+
 	priv->info->mac_port_get_caps(ds, port, config);
 }
 
@@ -3088,18 +3122,9 @@ mt753x_setup(struct dsa_switch *ds)
 static int mt753x_set_mac_eee(struct dsa_switch *ds, int port,
 			      struct ethtool_keee *e)
 {
-	struct mt7530_priv *priv = ds->priv;
-	u32 set, mask = LPI_THRESH_MASK | LPI_MODE_EN;
-
 	if (e->tx_lpi_timer > 0xFFF)
 		return -EINVAL;
 
-	set = LPI_THRESH_SET(e->tx_lpi_timer);
-	if (!e->tx_lpi_enabled)
-		/* Force LPI Mode without a delay */
-		set |= LPI_MODE_EN;
-	mt7530_rmw(priv, MT753X_PMEEECR_P(port), mask, set);
-
 	return 0;
 }
 
@@ -3238,6 +3263,8 @@ static const struct phylink_mac_ops mt753x_phylink_mac_ops = {
 	.mac_config	= mt753x_phylink_mac_config,
 	.mac_link_down	= mt753x_phylink_mac_link_down,
 	.mac_link_up	= mt753x_phylink_mac_link_up,
+	.mac_disable_tx_lpi = mt753x_phylink_mac_disable_tx_lpi,
+	.mac_enable_tx_lpi = mt753x_phylink_mac_enable_tx_lpi,
 };
 
 const struct mt753x_info mt753x_table[] = {
-- 
2.30.2

Re: [PATCH net-next 3/3] net: dsa: mt7530: convert to phylink managed EEE

[Chester A. Unal]

Hello Russell.

On 05/02/2025 15:11, Russell King (Oracle) wrote:
> Fixme: doesn't bit 25 and 26 also need to be set in the PMCR for
> PMCR_FORCE_EEE100 and PMCR_FORCE_EEE1G to take effect?

Yes, but only for MT7531 and the switch component of the MT7988 SoC. For
MT7530 and the switch component of the AN7581 SoC, bit 15
(MT7530_FORCE_MODE) must be set. The MT753X DSA subdriver sets these bits
accordingly at the setup function that pertains to the specific switch
model.

Chester A.

Re: [PATCH net-next 3/3] net: dsa: mt7530: convert to phylink managed EEE

[Russell King (Oracle)]

On Wed, Feb 05, 2025 at 03:42:30PM +0000, Chester A. Unal wrote:
> Hello Russell.
> 
> On 05/02/2025 15:11, Russell King (Oracle) wrote:
> > Fixme: doesn't bit 25 and 26 also need to be set in the PMCR for
> > PMCR_FORCE_EEE100 and PMCR_FORCE_EEE1G to take effect?
> 
> Yes, but only for MT7531 and the switch component of the MT7988 SoC. For
> MT7530 and the switch component of the AN7581 SoC, bit 15
> (MT7530_FORCE_MODE) must be set. The MT753X DSA subdriver sets these bits
> accordingly at the setup function that pertains to the specific switch
> model.

I'll remove the comment in the commit message. I also note from
patchwork that I need to remove lpi_timer_limit_us... so v2 will be
posted in the next day or so.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!