EEE support for rp1 mac

arch/arm64/boot/dts/broadcom/bcm2712-rpi-5-b.dts

@@ -175,8 +175,6 @@ rp1_target: &pcie2 {
 	phy1: ethernet-phy@1 {
 		reg = <0x1>;
 		brcm,powerdown-enable;
-		eee-broken-1000t;
-		eee-broken-100tx;
 	};
 };
 

arch/arm64/boot/dts/broadcom/bcm2712-rpi-cm5.dtsi

@@ -166,8 +166,6 @@ rp1_target: &pcie2 {
 		brcm,powerdown-enable;
 		interrupt-parent = <&rp1_gpio>;
 		interrupts = <37 IRQ_TYPE_LEVEL_LOW>;
-		eee-broken-1000t;
-		eee-broken-100tx;
 	};
 };
 

drivers/net/ethernet/cadence/macb.h

@@ -176,6 +176,10 @@
 #define GEM_PCSANNPTX		0x021c /* PCS AN Next Page TX */
 #define GEM_PCSANNPLP		0x0220 /* PCS AN Next Page LP */
 #define GEM_PCSANEXTSTS		0x023c /* PCS AN Extended Status */
+#define GEM_RXLPI		0x0270 /* EEE RX LPI Transitions */
+#define GEM_RXLPITIME		0x0274 /* EEE RX LPI Time */
+#define GEM_TXLPI		0x0278 /* EEE TX LPI Transitions */
+#define GEM_TXLPITIME		0x027c /* EEE TX LPI Time */
 #define GEM_DCFG1		0x0280 /* Design Config 1 */
 #define GEM_DCFG2		0x0284 /* Design Config 2 */
 #define GEM_DCFG3		0x0288 /* Design Config 3 */
@@ -258,6 +262,10 @@
 #define MACB_MIIONRGMII_OFFSET	28 /* MII Usage on RGMII Interface */
 #define MACB_MIIONRGMII_SIZE	1
 
+/* GEM specific NCR bitfields. */
+#define GEM_TXLPIEN_OFFSET	19 /* TX LPI Enable */
+#define GEM_TXLPIEN_SIZE	1
+
 /* Bitfields in NCFGR */
 #define MACB_SPD_OFFSET		0 /* Speed */
 #define MACB_SPD_SIZE		1
@@ -756,6 +764,7 @@
 #define MACB_CAPS_MIIONRGMII			0x00000200
 #define MACB_CAPS_NEED_TSUCLK			0x00000400
 #define MACB_CAPS_QUEUE_DISABLE			0x00000800
+#define MACB_CAPS_EEE				0x00001000
 #define MACB_CAPS_PCS				0x01000000
 #define MACB_CAPS_HIGH_SPEED			0x02000000
 #define MACB_CAPS_CLK_HW_CHG			0x04000000
@@ -1038,6 +1047,10 @@ struct gem_stats {
 	u32	rx_ip_header_checksum_errors;
 	u32	rx_tcp_checksum_errors;
 	u32	rx_udp_checksum_errors;
+	u32	rx_lpi_transitions;
+	u32	rx_lpi_time;
+	u32	tx_lpi_transitions;
+	u32	tx_lpi_time;
 };
 
 /* Describes the name and offset of an individual statistic register, as
@@ -1137,6 +1150,10 @@ static const struct gem_statistic gem_statistics[] = {
 			    GEM_BIT(NDS_RXERR)),
 	GEM_STAT_TITLE_BITS(RXUDPCCNT, "rx_udp_checksum_errors",
 			    GEM_BIT(NDS_RXERR)),
+	GEM_STAT_TITLE(RXLPI, "rx_lpi_transitions"),
+	GEM_STAT_TITLE(RXLPITIME, "rx_lpi_time"),
+	GEM_STAT_TITLE(TXLPI, "tx_lpi_transitions"),
+	GEM_STAT_TITLE(TXLPITIME, "tx_lpi_time"),
 };
 
 #define GEM_STATS_LEN ARRAY_SIZE(gem_statistics)
@@ -1341,6 +1358,12 @@ struct macb {
 
 	struct macb_ptp_info	*ptp_info;	/* macb-ptp interface */
 
+	/* EEE / LPI state */
+	bool			eee_active;
+	bool			tx_lpi_enabled;
+	struct delayed_work	tx_lpi_work;
+	unsigned int		tx_lpi_timer_ms; /* idle timeout before LPI */
+
 	struct phy		*sgmii_phy;	/* for ZynqMP SGMII mode */
 
 #ifdef MACB_EXT_DESC

drivers/net/ethernet/cadence/macb_main.c

@@ -656,6 +656,71 @@
 	.pcs_config = macb_pcs_config,
 };
 
+/* Default TX LPI idle timeout in milliseconds.
+ * The MAC will enter LPI after this period of TX inactivity.
+ */
+#define MACB_TX_LPI_TIMER_DEFAULT_MS	500
+
+/* PHY wake time from LPI in microseconds.
+ * IEEE 802.3az: Tw_sys is ~17us for 1000BASE-T, ~30us for 100BASE-TX.
+ * Use a conservative value to ensure the PHY has fully exited LPI.
+ */
+#define MACB_TX_LPI_WAKE_TIME_US	50
+
+static void macb_tx_lpi_set(struct macb *bp, bool enable)
+{
+	unsigned long flags;
+	u32 ncr;
+
+	spin_lock_irqsave(&bp->lock, flags);
+
+	ncr = macb_readl(bp, NCR);
+	if (enable)
+		ncr |= GEM_BIT(TXLPIEN);
+	else
+		ncr &= ~GEM_BIT(TXLPIEN);
+	macb_writel(bp, NCR, ncr);
+
+	bp->tx_lpi_enabled = enable;
+
+	spin_unlock_irqrestore(&bp->lock, flags);
+
+	netdev_dbg(bp->dev, "EEE TX LPI %s\n",
+		   enable ? "enabled" : "disabled");
+}
+
+static void macb_tx_lpi_work_fn(struct work_struct *work)
+{
+	struct macb *bp = container_of(work, struct macb, tx_lpi_work.work);
+
+	if (bp->eee_active)
+		macb_tx_lpi_set(bp, true);
+}
+
+/* Called from TX path to wake from LPI before transmitting */
+static inline void macb_tx_lpi_wake(struct macb *bp)
+{
+	if (!bp->tx_lpi_enabled)
+		return;
+
+	macb_tx_lpi_set(bp, false);
+	/* Cancel any pending re-entry */
+	cancel_delayed_work(&bp->tx_lpi_work);
+
+	/* Wait for PHY to exit LPI before transmitting */
+	udelay(MACB_TX_LPI_WAKE_TIME_US);
+}
+
+/* Schedule LPI re-entry after TX idle timeout */
+static inline void macb_tx_lpi_schedule(struct macb *bp)
+{
+	if (!bp->eee_active)
+		return;
+
+	mod_delayed_work(system_wq, &bp->tx_lpi_work,
+			 msecs_to_jiffies(bp->tx_lpi_timer_ms));
+}
+
 static void macb_mac_config(struct phylink_config *config, unsigned int mode,
 			    const struct phylink_link_state *state)
 {
@@ -728,10 +793,16 @@
 			queue_writel(queue, IDR,
 				     bp->rx_intr_mask | MACB_TX_INT_FLAGS | MACB_BIT(HRESP));
 
-	/* Disable Rx and Tx */
-	ctrl = macb_readl(bp, NCR) & ~(MACB_BIT(RE) | MACB_BIT(TE));
+	/* Cancel any pending LPI entry */
+	cancel_delayed_work(&bp->tx_lpi_work);
+
+	/* Disable TX LPI, Rx, and Tx */
+	ctrl = macb_readl(bp, NCR) & ~(GEM_BIT(TXLPIEN) | MACB_BIT(RE) | MACB_BIT(TE));
 	macb_writel(bp, NCR, ctrl);
 
+	bp->eee_active = false;
+	bp->tx_lpi_enabled = false;
+
 	netif_tx_stop_all_queues(ndev);
 }
 
@@ -799,6 +870,19 @@
 	macb_writel(bp, NCR, ctrl | MACB_BIT(RE) | MACB_BIT(TE));
 
 	netif_tx_wake_all_queues(ndev);
+
+	/* EEE: check if link partner negotiated EEE.
+	 * Per IEEE 802.3az / Microchip GMAC docs: LPI must not be
+	 * requested until the link has been up for at least 1 second.
+	 */
+	if (phy && (bp->caps & MACB_CAPS_EEE)) {
+		bp->eee_active = phy_init_eee(phy, false) >= 0 &&
+				 phy->enable_tx_lpi;
+		netdev_dbg(ndev, "EEE: active=%d\n", bp->eee_active);
+		if (bp->eee_active)
+			schedule_delayed_work(&bp->tx_lpi_work,
+					      msecs_to_jiffies(1000));
+	}
 }
 
 static struct phylink_pcs *macb_mac_select_pcs(struct phylink_config *config,
@@ -1312,6 +1396,11 @@
 	    CIRC_CNT(queue->tx_head, queue->tx_tail,
 		     bp->tx_ring_size) <= MACB_TX_WAKEUP_THRESH(bp))
 		netif_wake_subqueue(bp->dev, queue_index);
+
+	/* Schedule LPI re-entry when TX ring is drained */
+	if (queue->tx_head == queue->tx_tail)
+		macb_tx_lpi_schedule(bp);
+
 	spin_unlock_irqrestore(&queue->tx_ptr_lock, flags);
 
 	return packets;
@@ -2341,6 +2430,10 @@
 	bool is_lso;
 	netdev_tx_t ret = NETDEV_TX_OK;
 
+	/* Wake from LPI before transmitting */
+	if (unlikely(bp->tx_lpi_enabled))
+		macb_tx_lpi_wake(bp);
+
 	if (macb_clear_csum(skb)) {
 		dev_kfree_skb_any(skb);
 		return ret;
@@ -3064,6 +3157,9 @@
 	if (err)
 		goto phy_off;
 
+	if ((bp->caps & MACB_CAPS_EEE) && dev->phydev)
+		phy_support_eee(dev->phydev);
+
 	netif_tx_start_all_queues(dev);
 
 	if (bp->ptp_info)
@@ -3095,6 +3191,8 @@
 
 	netif_tx_stop_all_queues(dev);
 
+	cancel_delayed_work_sync(&bp->tx_lpi_work);
+
 	for (q = 0, queue = bp->queues; q < bp->num_queues; ++q, ++queue) {
 		napi_disable(&queue->napi_rx);
 		napi_disable(&queue->napi_tx);
@@ -3497,6 +3595,42 @@
 	return 0;
 }
 
+static int macb_get_eee(struct net_device *ndev, struct ethtool_keee *edata)
+{
+	struct macb *bp = netdev_priv(ndev);
+	int ret;
+
+	if (!(bp->caps & MACB_CAPS_EEE))
+		return -EOPNOTSUPP;
+
+	ret = phylink_ethtool_get_eee(bp->phylink, edata);
+	if (ret)
+		return ret;
+
+	edata->tx_lpi_timer = bp->tx_lpi_timer_ms * 1000;
+
+	return 0;
+}
+
+static int macb_set_eee(struct net_device *ndev, struct ethtool_keee *edata)
+{
+	struct macb *bp = netdev_priv(ndev);
+
+	if (!(bp->caps & MACB_CAPS_EEE))
+		return -EOPNOTSUPP;
+
+	if (edata->tx_lpi_timer)
+		bp->tx_lpi_timer_ms = edata->tx_lpi_timer / 1000;
+
+	/*
+	 * Don't directly control TXLPIEN here. phylink_ethtool_set_eee()
+	 * updates the PHY, which will bounce the link if tx_lpi_enabled
+	 * changes. That triggers mac_link_down/mac_link_up where we
+	 * enable/disable TXLPIEN based on the negotiated state.
+	 */
+	return phylink_ethtool_set_eee(bp->phylink, edata);
+}
+
 #ifdef CONFIG_MACB_USE_HWSTAMP
 static unsigned int gem_get_tsu_rate(struct macb *bp)
 {
@@ -3912,6 +4046,9 @@
 	.set_ringparam		= macb_set_ringparam,
 	.get_rxnfc			= gem_get_rxnfc,
 	.set_rxnfc			= gem_set_rxnfc,
+	.get_eee		= macb_get_eee,
+	.set_eee		= macb_set_eee,
+	.nway_reset		= phy_ethtool_nway_reset,
 };
 
 static int macb_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
@@ -5079,7 +5216,8 @@
 static const struct macb_config raspberrypi_rp1_config = {
 	.caps = MACB_CAPS_GIGABIT_MODE_AVAILABLE | MACB_CAPS_CLK_HW_CHG |
 		MACB_CAPS_JUMBO |
-		MACB_CAPS_GEM_HAS_PTP,
+		MACB_CAPS_GEM_HAS_PTP |
+		MACB_CAPS_EEE,
 	.dma_burst_length = 16,
 	.clk_init = macb_clk_init,
 	.init = macb_init,
@@ -5337,6 +5475,8 @@
 	}
 
 	INIT_WORK(&bp->hresp_err_bh_work, macb_hresp_error_task);
+	INIT_DELAYED_WORK(&bp->tx_lpi_work, macb_tx_lpi_work_fn);
+	bp->tx_lpi_timer_ms = MACB_TX_LPI_TIMER_DEFAULT_MS;
 
 	netdev_info(dev, "Cadence %s rev 0x%08x at 0x%08lx irq %d (%pM)\n",
 		    macb_is_gem(bp) ? "GEM" : "MACB", macb_readl(bp, MID),
@@ -5381,6 +5521,7 @@
 		mdiobus_free(bp->mii_bus);
 
 		device_set_wakeup_enable(&bp->pdev->dev, 0);
+		cancel_delayed_work_sync(&bp->tx_lpi_work);
 		cancel_work_sync(&bp->hresp_err_bh_work);
 		pm_runtime_disable(&pdev->dev);
 		pm_runtime_dont_use_autosuspend(&pdev->dev);

drivers/net/phy/phy.c

@@ -1728,7 +1728,7 @@ EXPORT_SYMBOL(phy_ethtool_get_eee);
  * phy_ethtool_set_eee_noneg - Adjusts MAC LPI configuration without PHY
  *			       renegotiation
  * @phydev: pointer to the target PHY device structure
- * @data: pointer to the ethtool_keee structure containing the new EEE settings
+ * @old_cfg: pointer to the eee_config structure containing the old EEE settings
  *
  * This function updates the Energy Efficient Ethernet (EEE) configuration
  * for cases where only the MAC's Low Power Idle (LPI) configuration changes,
@@ -1739,11 +1739,10 @@ EXPORT_SYMBOL(phy_ethtool_get_eee);
  * configuration.
  */
 static void phy_ethtool_set_eee_noneg(struct phy_device *phydev,
-				      struct ethtool_keee *data)
+				      const struct eee_config *old_cfg)
 {
-	if (phydev->eee_cfg.tx_lpi_enabled != data->tx_lpi_enabled ||
-	    phydev->eee_cfg.tx_lpi_timer != data->tx_lpi_timer) {
-		eee_to_eeecfg(&phydev->eee_cfg, data);
+	if (phydev->eee_cfg.tx_lpi_enabled != old_cfg->tx_lpi_enabled ||
+	    phydev->eee_cfg.tx_lpi_timer != old_cfg->tx_lpi_timer) {
 		phydev->enable_tx_lpi = eeecfg_mac_can_tx_lpi(&phydev->eee_cfg);
 		if (phydev->link) {
 			phydev->link = false;
@@ -1763,18 +1762,23 @@ static void phy_ethtool_set_eee_noneg(struct phy_device *phydev,
  */
 int phy_ethtool_set_eee(struct phy_device *phydev, struct ethtool_keee *data)
 {
+	struct eee_config old_cfg;
 	int ret;
 
 	if (!phydev->drv)
 		return -EIO;
 
 	mutex_lock(&phydev->lock);
+
+	old_cfg = phydev->eee_cfg;
+	eee_to_eeecfg(&phydev->eee_cfg, data);
+
 	ret = genphy_c45_ethtool_set_eee(phydev, data);
-	if (ret >= 0) {
-		if (ret == 0)
-			phy_ethtool_set_eee_noneg(phydev, data);
-		eee_to_eeecfg(&phydev->eee_cfg, data);
-	}
+	if (ret == 0)
+		phy_ethtool_set_eee_noneg(phydev, &old_cfg);
+	else if (ret < 0)
+		phydev->eee_cfg = old_cfg;
+
 	mutex_unlock(&phydev->lock);
 
 	return ret < 0 ? ret : 0;