Merge branch 'net-stmmac-clean-up-and-fix-eee-implementation'

Russell King says:

====================
net: stmmac: clean up and fix EEE implementation

This is a rework of stmmac's EEE support in light of the addition of EEE
management to phylib. It's slightly more than 15 patches, but I think it
makes sense to be so.

Patch 1 adds configuration of the receive clock phy_eee_rx_clock_stop()
(which was part of another series, but is necessary for this patch set.)

Patch 2 converts stmmac to use phylib's tracking of tx_lpi_timer.

Patch 3 corrects the data type used for things involving the LPI
timer. The user API uses u32, so stmmac should do too, rather than
blindly converting it to "int". eee_timer is left for patch 4.

Patch 4 (new) uses an unsigned int for eee_timer.

Patch 5 makes stmmac EEE state depend on phylib's enable_tx_lpi flag,
thus using phylib's resolution of EEE state.

Patch 6 removes redundant code from the ethtool EEE operations.

Patch 7 removes some redundant code in stmmac_disable_eee_mode()
and renames it to stmmac_disable_sw_eee_mode() to better reflect its
purpose.

Patch 8 removes the driver private tx_lpi_enabled, which is managed by
phylib since patch 4.

Patch 9 removes the dependence of EEE error statistics on the EEE
enable state, instead depending on whether EEE is supported by the
hardware.

Patch 10 removes phy_init_eee(), instead using phy_eee_rx_clock_stop()
to configure whether the PHY may stop the receive clock.

Patch 11 removes priv->eee_tw_timer, which is only ever set to one
value at probe time, effectively it is a constant. Hence this is
unnecessary complexity.

Patch 12 moves priv->eee_enabled into stmmac_eee_init(), and placing
it under the protection of priv->lock, except when EEE is not
supported (where it becomes constant-false.)

Patch 13 moves priv->eee_active also into stmmac_eee_init(), so
the indication whether EEE should be enabled or not is passed in
to this function.

Since both priv->eee_enabled and priv->eee_active are assigned
true/false values, they should be typed "bool". Make it sew in
patch 14. No Singer machine required.

Patch 15 moves the initialisation of priv->eee_ctrl_timer to the
probe function - it makes no sense to re-initialise the timer each
time we want to start using it.

Patch 16 removes the unnecessary EEE handling in the driver tear-down
method. The core net code will have brought the interface down
already, meaning EEE has already been disabled.

Patch 17 reorganises the code to split the hardware LPI timer
control paths from the software LPI timer paths.

Patch 18 works on this further by eliminating
stmmac_lpi_entry_timer_config() and making direct calls to the new
functions. This reveals a potential bug where priv->eee_sw_timer_en
is set true when EEE is disabled. This is not addressed in this
series, but will be in a future separate patch - so that if fixing
that causes a regression, it can be handled separately.
====================

Link: https://patch.msgid.link/Z36sHIlnExQBuFJE@shell.armlinux.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

6 files changed, 84 insertions, 87 deletions

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c b/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
index c36f90a782c5..9ed8620580a8 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
@@ -420,10 +420,10 @@ static void dwmac4_set_eee_pls(struct mac_device_info *hw, int link)
 	writel(value, ioaddr + GMAC4_LPI_CTRL_STATUS);
 }
 
-static void dwmac4_set_eee_lpi_entry_timer(struct mac_device_info *hw, int et)
+static void dwmac4_set_eee_lpi_entry_timer(struct mac_device_info *hw, u32 et)
 {
 	void __iomem *ioaddr = hw->pcsr;
-	int value = et & STMMAC_ET_MAX;
+	u32 value = et & STMMAC_ET_MAX;
 	int regval;
 
 	/* Program LPI entry timer value into register */
diff --git a/drivers/net/ethernet/stmicro/stmmac/hwif.h b/drivers/net/ethernet/stmicro/stmmac/hwif.h
index 2f7295b6c1c5..0f200b72c225 100644
--- a/drivers/net/ethernet/stmicro/stmmac/hwif.h
+++ b/drivers/net/ethernet/stmicro/stmmac/hwif.h
@@ -363,7 +363,7 @@ struct stmmac_ops {
 	void (*set_eee_mode)(struct mac_device_info *hw,
 			     bool en_tx_lpi_clockgating);
 	void (*reset_eee_mode)(struct mac_device_info *hw);
-	void (*set_eee_lpi_entry_timer)(struct mac_device_info *hw, int et);
+	void (*set_eee_lpi_entry_timer)(struct mac_device_info *hw, u32 et);
 	void (*set_eee_timer)(struct mac_device_info *hw, int ls, int tw);
 	void (*set_eee_pls)(struct mac_device_info *hw, int link);
 	void (*debug)(struct stmmac_priv *priv, void __iomem *ioaddr,
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
index 548b28fed9b6..e8dbce20129c 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
@@ -305,11 +305,9 @@ struct stmmac_priv {
 	int clk_csr;
 	struct timer_list eee_ctrl_timer;
 	int lpi_irq;
-	int eee_enabled;
-	int eee_active;
-	int tx_lpi_timer;
-	int tx_lpi_enabled;
-	int eee_tw_timer;
+	u32 tx_lpi_timer;
+	bool eee_enabled;
+	bool eee_active;
 	bool eee_sw_timer_en;
 	unsigned int mode;
 	unsigned int chain_mode;
@@ -405,8 +403,6 @@ void stmmac_dvr_remove(struct device *dev);
 int stmmac_dvr_probe(struct device *device,
 		     struct plat_stmmacenet_data *plat_dat,
 		     struct stmmac_resources *res);
-void stmmac_disable_eee_mode(struct stmmac_priv *priv);
-bool stmmac_eee_init(struct stmmac_priv *priv);
 int stmmac_reinit_queues(struct net_device *dev, u32 rx_cnt, u32 tx_cnt);
 int stmmac_reinit_ringparam(struct net_device *dev, u32 rx_size, u32 tx_size);
 int stmmac_bus_clks_config(struct stmmac_priv *priv, bool enabled);
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
index 16b4d8c21c90..918a32f8fda8 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
@@ -654,7 +654,7 @@ static void stmmac_get_ethtool_stats(struct net_device *dev,
 					     (*(u32 *)p);
 			}
 		}
-		if (priv->eee_enabled) {
+		if (priv->dma_cap.eee) {
 			int val = phylink_get_eee_err(priv->phylink);
 			if (val)
 				priv->xstats.phy_eee_wakeup_error_n = val;
@@ -898,9 +898,6 @@ static int stmmac_ethtool_op_get_eee(struct net_device *dev,
 	if (!priv->dma_cap.eee)
 		return -EOPNOTSUPP;
 
-	edata->tx_lpi_timer = priv->tx_lpi_timer;
-	edata->tx_lpi_enabled = priv->tx_lpi_enabled;
-
 	return phylink_ethtool_get_eee(priv->phylink, edata);
 }
 
@@ -908,29 +905,11 @@ static int stmmac_ethtool_op_set_eee(struct net_device *dev,
 				     struct ethtool_keee *edata)
 {
 	struct stmmac_priv *priv = netdev_priv(dev);
-	int ret;
 
 	if (!priv->dma_cap.eee)
 		return -EOPNOTSUPP;
 
-	if (priv->tx_lpi_enabled != edata->tx_lpi_enabled)
-		netdev_warn(priv->dev,
-			    "Setting EEE tx-lpi is not supported\n");
-
-	if (!edata->eee_enabled)
-		stmmac_disable_eee_mode(priv);
-
-	ret = phylink_ethtool_set_eee(priv->phylink, edata);
-	if (ret)
-		return ret;
-
-	if (edata->eee_enabled &&
-	    priv->tx_lpi_timer != edata->tx_lpi_timer) {
-		priv->tx_lpi_timer = edata->tx_lpi_timer;
-		stmmac_eee_init(priv);
-	}
-
-	return 0;
+	return phylink_ethtool_set_eee(priv->phylink, edata);
 }
 
 static u32 stmmac_usec2riwt(u32 usec, struct stmmac_priv *priv)
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 038df1b2bb58..58b013528dea 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -111,8 +111,8 @@ static const u32 default_msg_level = (NETIF_MSG_DRV | NETIF_MSG_PROBE |
 				      NETIF_MSG_IFDOWN | NETIF_MSG_TIMER);
 
 #define STMMAC_DEFAULT_LPI_TIMER	1000
-static int eee_timer = STMMAC_DEFAULT_LPI_TIMER;
-module_param(eee_timer, int, 0644);
+static unsigned int eee_timer = STMMAC_DEFAULT_LPI_TIMER;
+module_param(eee_timer, uint, 0644);
 MODULE_PARM_DESC(eee_timer, "LPI tx expiration time in msec");
 #define STMMAC_LPI_T(x) (jiffies + usecs_to_jiffies(x))
 
@@ -194,8 +194,6 @@ static void stmmac_verify_args(void)
 		flow_ctrl = FLOW_OFF;
 	if (unlikely((pause < 0) || (pause > 0xffff)))
 		pause = PAUSE_TIME;
-	if (eee_timer < 0)
-		eee_timer = STMMAC_DEFAULT_LPI_TIMER;
 }
 
 static void __stmmac_disable_all_queues(struct stmmac_priv *priv)
@@ -392,14 +390,14 @@ static inline u32 stmmac_rx_dirty(struct stmmac_priv *priv, u32 queue)
 	return dirty;
 }
 
-static void stmmac_lpi_entry_timer_config(struct stmmac_priv *priv, bool en)
+static void stmmac_disable_hw_lpi_timer(struct stmmac_priv *priv)
 {
-	int tx_lpi_timer;
+	stmmac_set_eee_lpi_timer(priv, priv->hw, 0);
+}
 
-	/* Clear/set the SW EEE timer flag based on LPI ET enablement */
-	priv->eee_sw_timer_en = en ? 0 : 1;
-	tx_lpi_timer  = en ? priv->tx_lpi_timer : 0;
-	stmmac_set_eee_lpi_timer(priv, priv->hw, tx_lpi_timer);
+static void stmmac_enable_hw_lpi_timer(struct stmmac_priv *priv)
+{
+	stmmac_set_eee_lpi_timer(priv, priv->hw, priv->tx_lpi_timer);
 }
 
 /**
@@ -429,18 +427,13 @@ static int stmmac_enable_eee_mode(struct stmmac_priv *priv)
 }
 
 /**
- * stmmac_disable_eee_mode - disable and exit from LPI mode
+ * stmmac_disable_sw_eee_mode - disable and exit from LPI mode
  * @priv: driver private structure
  * Description: this function is to exit and disable EEE in case of
  * LPI state is true. This is called by the xmit.
  */
-void stmmac_disable_eee_mode(struct stmmac_priv *priv)
+static void stmmac_disable_sw_eee_mode(struct stmmac_priv *priv)
 {
-	if (!priv->eee_sw_timer_en) {
-		stmmac_lpi_entry_timer_config(priv, 0);
-		return;
-	}
-
 	stmmac_reset_eee_mode(priv, priv->hw);
 	del_timer_sync(&priv->eee_ctrl_timer);
 	priv->tx_path_in_lpi_mode = false;
@@ -464,18 +457,21 @@ static void stmmac_eee_ctrl_timer(struct timer_list *t)
 /**
  * stmmac_eee_init - init EEE
  * @priv: driver private structure
+ * @active: indicates whether EEE should be enabled.
  * Description:
  *  if the GMAC supports the EEE (from the HW cap reg) and the phy device
  *  can also manage EEE, this function enable the LPI state and start related
  *  timer.
  */
-bool stmmac_eee_init(struct stmmac_priv *priv)
+static void stmmac_eee_init(struct stmmac_priv *priv, bool active)
 {
-	int eee_tw_timer = priv->eee_tw_timer;
+	priv->eee_active = active;
 
 	/* Check if MAC core supports the EEE feature. */
-	if (!priv->dma_cap.eee)
-		return false;
+	if (!priv->dma_cap.eee) {
+		priv->eee_enabled = false;
+		return;
+	}
 
 	mutex_lock(&priv->lock);
 
@@ -483,22 +479,24 @@ bool stmmac_eee_init(struct stmmac_priv *priv)
 	if (!priv->eee_active) {
 		if (priv->eee_enabled) {
 			netdev_dbg(priv->dev, "disable EEE\n");
-			stmmac_lpi_entry_timer_config(priv, 0);
+			priv->eee_sw_timer_en = true;
+			stmmac_disable_hw_lpi_timer(priv);
 			del_timer_sync(&priv->eee_ctrl_timer);
-			stmmac_set_eee_timer(priv, priv->hw, 0, eee_tw_timer);
+			stmmac_set_eee_timer(priv, priv->hw, 0,
+					     STMMAC_DEFAULT_TWT_LS);
 			if (priv->hw->xpcs)
 				xpcs_config_eee(priv->hw->xpcs,
 						priv->plat->mult_fact_100ns,
 						false);
 		}
+		priv->eee_enabled = false;
 		mutex_unlock(&priv->lock);
-		return false;
+		return;
 	}
 
 	if (priv->eee_active && !priv->eee_enabled) {
-		timer_setup(&priv->eee_ctrl_timer, stmmac_eee_ctrl_timer, 0);
 		stmmac_set_eee_timer(priv, priv->hw, STMMAC_DEFAULT_LIT_LS,
-				     eee_tw_timer);
+				     STMMAC_DEFAULT_TWT_LS);
 		if (priv->hw->xpcs)
 			xpcs_config_eee(priv->hw->xpcs,
 					priv->plat->mult_fact_100ns,
@@ -506,18 +504,23 @@ bool stmmac_eee_init(struct stmmac_priv *priv)
 	}
 
 	if (priv->plat->has_gmac4 && priv->tx_lpi_timer <= STMMAC_ET_MAX) {
+		/* Use hardware LPI mode */
 		del_timer_sync(&priv->eee_ctrl_timer);
 		priv->tx_path_in_lpi_mode = false;
-		stmmac_lpi_entry_timer_config(priv, 1);
+		priv->eee_sw_timer_en = false;
+		stmmac_enable_hw_lpi_timer(priv);
 	} else {
-		stmmac_lpi_entry_timer_config(priv, 0);
+		/* Use software LPI mode */
+		priv->eee_sw_timer_en = true;
+		stmmac_disable_hw_lpi_timer(priv);
 		mod_timer(&priv->eee_ctrl_timer,
 			  STMMAC_LPI_T(priv->tx_lpi_timer));
 	}
 
+	priv->eee_enabled = true;
+
 	mutex_unlock(&priv->lock);
 	netdev_dbg(priv->dev, "Energy-Efficient Ethernet initialized\n");
-	return true;
 }
 
 /* stmmac_get_tx_hwtstamp - get HW TX timestamps
@@ -974,9 +977,7 @@ static void stmmac_mac_link_down(struct phylink_config *config,
 	struct stmmac_priv *priv = netdev_priv(to_net_dev(config->dev));
 
 	stmmac_mac_set(priv, priv->ioaddr, false);
-	priv->eee_active = false;
-	priv->tx_lpi_enabled = false;
-	priv->eee_enabled = stmmac_eee_init(priv);
+	stmmac_eee_init(priv, false);
 	stmmac_set_eee_pls(priv, priv->hw, false);
 
 	if (stmmac_fpe_supported(priv))
@@ -1085,11 +1086,10 @@ static void stmmac_mac_link_up(struct phylink_config *config,
 
 	stmmac_mac_set(priv, priv->ioaddr, true);
 	if (phy && priv->dma_cap.eee) {
-		priv->eee_active =
-			phy_init_eee(phy, !(priv->plat->flags &
-				STMMAC_FLAG_RX_CLK_RUNS_IN_LPI)) >= 0;
-		priv->eee_enabled = stmmac_eee_init(priv);
-		priv->tx_lpi_enabled = priv->eee_enabled;
+		phy_eee_rx_clock_stop(phy, !(priv->plat->flags &
+					     STMMAC_FLAG_RX_CLK_RUNS_IN_LPI));
+		priv->tx_lpi_timer = phy->eee_cfg.tx_lpi_timer;
+		stmmac_eee_init(priv, phy->enable_tx_lpi);
 		stmmac_set_eee_pls(priv, priv->hw, true);
 	}
 
@@ -1187,6 +1187,16 @@ static int stmmac_init_phy(struct net_device *dev)
 		ret = phylink_fwnode_phy_connect(priv->phylink, fwnode, 0);
 	}
 
+	if (ret == 0) {
+		struct ethtool_keee eee;
+
+		/* Configure phylib's copy of the LPI timer */
+		if (!phylink_ethtool_get_eee(priv->phylink, &eee)) {
+			eee.tx_lpi_timer = priv->tx_lpi_timer;
+			phylink_ethtool_set_eee(priv->phylink, &eee);
+		}
+	}
+
 	if (!priv->plat->pmt) {
 		struct ethtool_wolinfo wol = { .cmd = ETHTOOL_GWOL };
 
@@ -3452,12 +3462,6 @@ static int stmmac_hw_setup(struct net_device *dev, bool ptp_register)
 	else if (ptp_register)
 		stmmac_ptp_register(priv);
 
-	priv->eee_tw_timer = STMMAC_DEFAULT_TWT_LS;
-
-	/* Convert the timer from msec to usec */
-	if (!priv->tx_lpi_timer)
-		priv->tx_lpi_timer = eee_timer * 1000;
-
 	if (priv->use_riwt) {
 		u32 queue;
 
@@ -3924,6 +3928,10 @@ static int __stmmac_open(struct net_device *dev,
 	u32 chan;
 	int ret;
 
+	/* Initialise the tx lpi timer, converting from msec to usec */
+	if (!priv->tx_lpi_timer)
+		priv->tx_lpi_timer = eee_timer * 1000;
+
 	ret = pm_runtime_resume_and_get(priv->device);
 	if (ret < 0)
 		return ret;
@@ -4038,11 +4046,6 @@ static int stmmac_release(struct net_device *dev)
 	/* Free the IRQ lines */
 	stmmac_free_irq(dev, REQ_IRQ_ERR_ALL, 0);
 
-	if (priv->eee_enabled) {
-		priv->tx_path_in_lpi_mode = false;
-		del_timer_sync(&priv->eee_ctrl_timer);
-	}
-
 	/* Stop TX/RX DMA and clear the descriptors */
 	stmmac_stop_all_dma(priv);
 
@@ -4494,7 +4497,7 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
 	first_tx = tx_q->cur_tx;
 
 	if (priv->tx_path_in_lpi_mode && priv->eee_sw_timer_en)
-		stmmac_disable_eee_mode(priv);
+		stmmac_disable_sw_eee_mode(priv);
 
 	/* Manage oversized TCP frames for GMAC4 device */
 	if (skb_is_gso(skb) && priv->tso) {
@@ -7409,6 +7412,8 @@ int stmmac_dvr_probe(struct device *device,
 
 	INIT_WORK(&priv->service_task, stmmac_service_task);
 
+	timer_setup(&priv->eee_ctrl_timer, stmmac_eee_ctrl_timer, 0);
+
 	/* Override with kernel parameters if supplied XXX CRS XXX
 	 * this needs to have multiple instances
 	 */
diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index e4b04cdaa995..a4b9fcc2503a 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -1641,6 +1641,27 @@ void phy_mac_interrupt(struct phy_device *phydev)
 EXPORT_SYMBOL(phy_mac_interrupt);
 
 /**
+ * phy_eee_rx_clock_stop() - configure PHY receive clock in LPI
+ * @phydev: target phy_device struct
+ * @clk_stop_enable: flag to indicate whether the clock can be stopped
+ *
+ * Configure whether the PHY can disable its receive clock during LPI mode,
+ * See IEEE 802.3 sections 22.2.2.2, 35.2.2.10, and 45.2.3.1.4.
+ *
+ * Returns: 0 or negative error.
+ */
+int phy_eee_rx_clock_stop(struct phy_device *phydev, bool clk_stop_enable)
+{
+	/* Configure the PHY to stop receiving xMII
+	 * clock while it is signaling LPI.
+	 */
+	return phy_modify_mmd(phydev, MDIO_MMD_PCS, MDIO_CTRL1,
+			      MDIO_PCS_CTRL1_CLKSTOP_EN,
+			      clk_stop_enable ? MDIO_PCS_CTRL1_CLKSTOP_EN : 0);
+}
+EXPORT_SYMBOL_GPL(phy_eee_rx_clock_stop);
+
+/**
  * phy_init_eee - init and check the EEE feature
  * @phydev: target phy_device struct
  * @clk_stop_enable: PHY may stop the clock during LPI
@@ -1664,11 +1685,7 @@ int phy_init_eee(struct phy_device *phydev, bool clk_stop_enable)
 		return -EPROTONOSUPPORT;
 
 	if (clk_stop_enable)
-		/* Configure the PHY to stop receiving xMII
-		 * clock while it is signaling LPI.
-		 */
-		ret = phy_set_bits_mmd(phydev, MDIO_MMD_PCS, MDIO_CTRL1,
-				       MDIO_PCS_CTRL1_CLKSTOP_EN);
+		ret = phy_eee_rx_clock_stop(phydev, true);
 
 	return ret < 0 ? ret : 0;
 }