Re: [Linux-stm32] [PATCH RFC net-next 6/7] net: stmmac: add helpers to indicate WoL enable status

["Russell King (Oracle)" <linux@armlinux.org.uk>]

> On 7/28/25 19:54, Russell King (Oracle) wrote:
> > On Mon, Jul 28, 2025 at 07:28:01PM +0200, Andrew Lunn wrote:
> > > > +static inline bool stmmac_wol_enabled_mac(struct stmmac_priv *priv)
> > > > +{
> > > > +	return priv->plat->pmt && device_may_wakeup(priv->device);
> > > > +}
> > > > +
> > > > +static inline bool stmmac_wol_enabled_phy(struct stmmac_priv *priv)
> > > > +{
> > > > +	return !priv->plat->pmt && device_may_wakeup(priv->device);
> > > > +}
> > > 
> > > I agree this is a direct translation into a helper.
> > > 
> > > Reviewed-by: Andrew Lunn <andrew@lunn.ch>
> > > 
> > > I'm guessing at some point you want to change these two
> > > helpers. e.g. at some point, you want to try getting the PHY to do the
> > > WoL, independent of !priv->plat->pmt?
> > > 
> > > > -	if (device_may_wakeup(priv->device) && !priv->plat->pmt)
> > > > +	if (stmmac_wol_enabled_phy(priv))
> > > >   		phylink_speed_down(priv->phylink, false);
> > > 
> > > This might be related to the next patch. But why only do speed down
> > > when PHY is doing WoL? If the MAC is doing WoL, you could also do a
> > > speed_down.
> > 
> > No idea, but that's what the code currently does, and, as ever with
> > a cleanup series, I try to avoid functional changes in cleanup series.
> > 
> > Also, bear in mind that I can't test any of this.
> > 
> > We haven't yet been successful in getting WoL working in mainline. It
> > _seems_ that the Jetson Xaiver NX platform should be using PHY mode,
> > but the Realtek PHY driver is definitely broken for WoL. Even with
> > that hacked, and along with other fixes that I've been given, I still
> > can't get the SoC to wake up via WoL. In fact, the changes to change
> > DT to specify the PHY interrupt as being routed through the PM
> > controller results in normal PHY link up/down interrupts no longer
> > working.
> > 
> > I'd like someone else to test functional changes!
> > 
> 
> Hello Russel,

That's "Russell" please.

> First of all, thank you for taking the time to improve this code.
> What exactly do you mean by hacking? Forcing !priv->plat->pmt?

No. There's a cleaner way to clear ->pmt which isn't hacky. Thierry's
patch to .dts also isn't hacky.

With Thierry's .dts patch, PHY interrupts completely stop working, so
we don't get link change notifications anymore - and we still don't
seem to be capable of waking the system up with the PHY interrupt
being asserted.

Without Thierry's .dts patch, as I predicted, enabling WoL at the
PHY results in Bad Stuff happening - the code in the realtek driver
for WoL is quite simply broken and wrong.

Switching the pin from INTB mode to PMEB mode results in:
- No link change interrupts once WoL is enabled
- The interrupt output being stuck at active level, causing an
  interrupt storm and the interrupt is eventually disabled.
  The PHY can be configured to pulse the PMEB or hold at an active
  level until the WoL is cleared - and by default it's the latter.

So, switching the interrupt pin to PMEB mode is simply wrong and
breaks phylib. I guess the original WoL support was only tested on
a system which didn't use the PHY interrupt, only using the interrupt
pin for wake-up purposes.

I was working on the realtek driver to fix this, but it's pointless
spending time on this until the rest of the system can wake up -
and thus the changes can be tested. This is where I got to (and
includes work from both Thierry and myself, so please don't pick
this up as-is, because I can guarantee that you'll get the sign-offs
wrong! It's a work-in-progress, and should be a series for submission.)

diff --git a/arch/arm64/boot/dts/nvidia/tegra194-p3668.dtsi b/arch/arm64/boot/dts/nvidia/tegra194-p3668.dtsi
index a410fc335fa3..f7c9c14b095e 100644
--- a/arch/arm64/boot/dts/nvidia/tegra194-p3668.dtsi
+++ b/arch/arm64/boot/dts/nvidia/tegra194-p3668.dtsi
@@ -39,8 +39,8 @@ mdio {
 				phy: ethernet-phy@0 {
 					compatible = "ethernet-phy-ieee802.3-c22";
 					reg = <0x0>;
-					interrupt-parent = <&gpio>;
-					interrupts = <TEGRA194_MAIN_GPIO(G, 4) IRQ_TYPE_LEVEL_LOW>;
+					interrupt-parent = <&pmc>;
+					interrupts = <20 IRQ_TYPE_LEVEL_LOW>;
 					#phy-cells = <0>;
 				};
 			};
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-dwc-qos-eth.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-dwc-qos-eth.c
index 09ae16e026eb..bcaa37e08345 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-dwc-qos-eth.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-dwc-qos-eth.c
@@ -261,7 +261,8 @@ static int tegra_eqos_probe(struct platform_device *pdev,
 	plat_dat->set_clk_tx_rate = stmmac_set_clk_tx_rate;
 	plat_dat->bsp_priv = eqos;
 	plat_dat->flags |= STMMAC_FLAG_SPH_DISABLE |
-			   STMMAC_FLAG_EN_TX_LPI_CLK_PHY_CAP;
+			   STMMAC_FLAG_EN_TX_LPI_CLK_PHY_CAP |
+			   STMMAC_FLAG_USE_PHY_WOL;
 
 	return 0;
 
diff --git a/drivers/net/phy/realtek/realtek_main.c b/drivers/net/phy/realtek/realtek_main.c
index dd0d675149ad..fdd926d3ab83 100644
--- a/drivers/net/phy/realtek/realtek_main.c
+++ b/drivers/net/phy/realtek/realtek_main.c
@@ -31,6 +31,7 @@
 #define RTL821x_INER				0x12
 #define RTL8211B_INER_INIT			0x6400
 #define RTL8211E_INER_LINK_STATUS		BIT(10)
+#define RTL8211F_INER_WOL			BIT(7)
 #define RTL8211F_INER_LINK_STATUS		BIT(4)
 
 #define RTL821x_INSR				0x13
@@ -426,12 +427,15 @@ static irqreturn_t rtl8211f_handle_interrupt(struct phy_device *phydev)
 		return IRQ_NONE;
 	}
 
-	if (!(irq_status & RTL8211F_INER_LINK_STATUS))
-		return IRQ_NONE;
+	if (irq_status & RTL8211F_INER_LINK_STATUS) {
+		phy_trigger_machine(phydev);
+		return IRQ_HANDLED;
+	}
 
-	phy_trigger_machine(phydev);
+	if (irq_status & RTL8211F_INER_WOL)
+		return IRQ_HANDLED;
 
-	return IRQ_HANDLED;
+	return IRQ_NONE;
 }
 
 static void rtl8211f_get_wol(struct phy_device *dev, struct ethtool_wolinfo *wol)
@@ -451,6 +455,7 @@ static void rtl8211f_get_wol(struct phy_device *dev, struct ethtool_wolinfo *wol
 static int rtl8211f_set_wol(struct phy_device *dev, struct ethtool_wolinfo *wol)
 {
 	const u8 *mac_addr = dev->attached_dev->dev_addr;
+	struct rtl821x_priv *priv = phydev->priv;
 	int oldpage;
 
 	oldpage = phy_save_page(dev);
@@ -470,23 +475,44 @@ static int rtl8211f_set_wol(struct phy_device *dev, struct ethtool_wolinfo *wol)
 		__phy_write(dev, RTL8211F_WOL_SETTINGS_STATUS, RTL8211F_WOL_STATUS_RESET);
 
 		/* Enable the WOL interrupt */
-		rtl821x_write_page(dev, RTL8211F_INTBCR_PAGE);
-		__phy_set_bits(dev, RTL8211F_INTBCR, RTL8211F_INTBCR_INTB_PMEB);
+		//rtl821x_write_page(dev, RTL8211F_INTBCR_PAGE);
+		//__phy_set_bits(dev, RTL8211F_INTBCR, RTL8211F_INTBCR_INTB_PMEB);
+		rtl821x_write_page(dev, 0xa42);
+		__phy_set_bits(dev, RTL821x_INER, RTL8211F_INER_WOL);
 	} else {
 		/* Disable the WOL interrupt */
-		rtl821x_write_page(dev, RTL8211F_INTBCR_PAGE);
-		__phy_clear_bits(dev, RTL8211F_INTBCR, RTL8211F_INTBCR_INTB_PMEB);
+		//rtl821x_write_page(dev, RTL8211F_INTBCR_PAGE);
+		//__phy_clear_bits(dev, RTL8211F_INTBCR, RTL8211F_INTBCR_INTB_PMEB);
+		rtl821x_write_page(dev, 0xa42);
+		__phy_clear_bits(dev, RTL821x_INER, RTL8211F_INER_WOL);
 
 		/* Disable magic packet matching and reset WOL status */
 		rtl821x_write_page(dev, RTL8211F_WOL_SETTINGS_PAGE);
 		__phy_write(dev, RTL8211F_WOL_SETTINGS_EVENTS, 0);
 		__phy_write(dev, RTL8211F_WOL_SETTINGS_STATUS, RTL8211F_WOL_STATUS_RESET);
 	}
+	priv->saved_wolopts = wolopts;
 
 err:
 	return phy_restore_page(dev, oldpage, 0);
 }
 
+static int rtl8211f_suspend(struct phy_device *phydev)
+{
+	struct rtl821x_priv *priv = phydev->priv;
+	int ret = rtl821x_suspend(phydev);
+
+	return ret;
+}
+
+static int rtl8211f_resume(struct phy_device *phydev)
+{
+	struct rtl821x_priv *priv = phydev->priv;
+	int ret = rtl821x_resume(phydev);
+
+	return ret;
+}
+
 static int rtl8211_config_aneg(struct phy_device *phydev)
 {
 	int ret;
@@ -1619,8 +1645,8 @@ static struct phy_driver realtek_drvs[] = {
 		.handle_interrupt = rtl8211f_handle_interrupt,
 		.set_wol	= rtl8211f_set_wol,
 		.get_wol	= rtl8211f_get_wol,
-		.suspend	= rtl821x_suspend,
-		.resume		= rtl821x_resume,
+		.suspend	= rtl8211f_suspend,
+		.resume		= rtl8211f_resume,
 		.read_page	= rtl821x_read_page,
 		.write_page	= rtl821x_write_page,
 		.flags		= PHY_ALWAYS_CALL_SUSPEND,

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