[PATCH net-next 0/3] net: stmmac: pcs preparation

[PATCH net-next 0/3] net: stmmac: pcs preparation

[Russell King (Oracle)]

Hi,

These three patches prepare for the PCS changes, which, subject to
Qualcomm testing, should be coming in the next cycle.

 .../net/ethernet/stmicro/stmmac/dwxgmac2_core.c    |  2 --
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c  | 18 ++++++++++---
 drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.c   | 31 +++++++++++++++++++---
 drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h   | 24 ++---------------
 4 files changed, 44 insertions(+), 31 deletions(-)

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

[PATCH net-next 1/3] net: stmmac: clear half-duplex caps where unsupported

[Russell King (Oracle)]

Where a core supports hardware features, but does not indicate support
for half-duplex, clear phylink's half-duplex 1G, 100M and 10M
capability bits to disallow half-duplex operation and advertisement of
these link modes.

This will avoid the need for special code in the PCS driver to do this
based on the ESTATUS register bits, as the support in the PCS is
dependent on the same synthesis choice as the MAC core.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
---
 drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c | 2 --
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c   | 3 +++
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c
index ca81bb1cae39..49893b9fb88c 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c
@@ -46,8 +46,6 @@ static void dwxgmac2_update_caps(struct stmmac_priv *priv)
 {
 	if (!priv->dma_cap.mbps_10_100)
 		priv->hw->link.caps &= ~(MAC_10 | MAC_100);
-	else if (!priv->dma_cap.half_duplex)
-		priv->hw->link.caps &= ~(MAC_10HD | MAC_100HD);
 }
 
 static void dwxgmac2_set_mac(void __iomem *ioaddr, bool enable)
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 788b884f9c89..a3c155cccd9b 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -906,6 +906,9 @@ static unsigned long stmmac_mac_get_caps(struct phylink_config *config,
 	/* Refresh the MAC-specific capabilities */
 	stmmac_mac_update_caps(priv);
 
+	if (priv->hw_cap_support && !priv->dma_cap.half_duplex)
+		priv->hw->link.caps &= ~(MAC_1000HD | MAC_100HD | MAC_10HD);
+
 	config->mac_capabilities = priv->hw->link.caps;
 
 	if (priv->plat->max_speed)
-- 
2.47.3

Re: [PATCH net-next 1/3] net: stmmac: clear half-duplex caps where unsupported

[Maxime Chevallier]

Hi,

On 30/01/2026 12:10, Russell King (Oracle) wrote:
> Where a core supports hardware features, but does not indicate support
> for half-duplex, clear phylink's half-duplex 1G, 100M and 10M
> capability bits to disallow half-duplex operation and advertisement of
> these link modes.
> 
> This will avoid the need for special code in the PCS driver to do this
> based on the ESTATUS register bits, as the support in the PCS is
> dependent on the same synthesis choice as the MAC core.
> 
> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

Gave it a quick test on socfpga, as this impacts all variants,
and we seem to be good so,

Tested-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com>

Maxime

Re: [PATCH net-next 1/3] net: stmmac: clear half-duplex caps where unsupported

[Russell King (Oracle)]

On Fri, Jan 30, 2026 at 06:29:23PM +0100, Maxime Chevallier wrote:
> Hi,
> 
> On 30/01/2026 12:10, Russell King (Oracle) wrote:
> > Where a core supports hardware features, but does not indicate support
> > for half-duplex, clear phylink's half-duplex 1G, 100M and 10M
> > capability bits to disallow half-duplex operation and advertisement of
> > these link modes.
> > 
> > This will avoid the need for special code in the PCS driver to do this
> > based on the ESTATUS register bits, as the support in the PCS is
> > dependent on the same synthesis choice as the MAC core.
> > 
> > Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
> 
> Gave it a quick test on socfpga, as this impacts all variants,
> and we seem to be good so,
> 
> Tested-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
> Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com>

If you look at /sys/kernel/debug/stmmaceth/ethX/dma_cap, it should
say whether half duplex is supported (I guess in your case it will
be, it's probably very unlikely not to be.) However, would be worth
knowing whether the if() is taken or not!

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

Re: [PATCH net-next 1/3] net: stmmac: clear half-duplex caps where unsupported

[Maxime Chevallier]

On 30/01/2026 19:09, Russell King (Oracle) wrote:

> If you look at /sys/kernel/debug/stmmaceth/ethX/dma_cap, it should
> say whether half duplex is supported (I guess in your case it will
> be, it's probably very unlikely not to be.) However, would be worth
> knowing whether the if() is taken or not!
> 

Just rebuilt a kernel w/ debugfs support, and indeed I have :
[...]
	10/100 Mbps: Y
	1000 Mbps: Y
	Half duplex: Y
[...]

So looks like the if() isn't taken :)

Maxime

[PATCH net-next 2/3] net: stmmac: move most PCS register definitions to stmmac_pcs.c

[Russell King (Oracle)]

Move most of the PCS register offset definitions to stmmac_pcs.c.
Since stmmac_pcs.c only ever passes zero into the register offset
macros, remove that ability, making them simple constant integer
definitions.

Add appropriate descriptions of the registers, pointing out their
similarity with their IEEE 802.3 counterparts. Make use of the
BMSR definitions for the GMAC_AN_STATUS register and remove the
driver private versions.

Note that BMSR_LSTATUS is non-low-latching, unlike it's 802.3z
counterpart.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
---
 .../net/ethernet/stmicro/stmmac/stmmac_pcs.c  | 22 +++++++++++++++----
 .../net/ethernet/stmicro/stmmac/stmmac_pcs.h  | 22 -------------------
 2 files changed, 18 insertions(+), 26 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.c
index 2f826fe7229b..e827c03ae932 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.c
@@ -2,6 +2,20 @@
 #include "stmmac.h"
 #include "stmmac_pcs.h"
 
+/*
+ * GMAC_AN_STATUS is equivalent to MII_BMSR
+ * GMAC_ANE_ADV is equivalent to 802.3z MII_ADVERTISE
+ * GMAC_ANE_LPA is equivalent to 802.3z MII_LPA
+ * GMAC_ANE_EXP is equivalent to MII_EXPANSION
+ * GMAC_TBI is equivalent to MII_ESTATUS
+ *
+ * ADV, LPA and EXP are only available for the TBI and RTBI modes.
+ */
+#define GMAC_AN_STATUS	0x04	/* AN status */
+#define GMAC_ANE_ADV	0x08	/* ANE Advertisement */
+#define GMAC_ANE_LPA	0x0c	/* ANE link partener ability */
+#define GMAC_TBI	0x14	/* TBI extend status */
+
 static int dwmac_integrated_pcs_enable(struct phylink_pcs *pcs)
 {
 	struct stmmac_pcs *spcs = phylink_pcs_to_stmmac_pcs(pcs);
@@ -49,11 +63,11 @@ void stmmac_integrated_pcs_irq(struct stmmac_priv *priv, u32 status,
 			       struct stmmac_extra_stats *x)
 {
 	struct stmmac_pcs *spcs = priv->integrated_pcs;
-	u32 val = readl(spcs->base + GMAC_AN_STATUS(0));
+	u32 val = readl(spcs->base + GMAC_AN_STATUS);
 
 	if (status & PCS_ANE_IRQ) {
 		x->irq_pcs_ane_n++;
-		if (val & GMAC_AN_STATUS_ANC)
+		if (val & BMSR_ANEGCOMPLETE)
 			dev_info(priv->device,
 				 "PCS ANE process completed\n");
 	}
@@ -61,9 +75,9 @@ void stmmac_integrated_pcs_irq(struct stmmac_priv *priv, u32 status,
 	if (status & PCS_LINK_IRQ) {
 		x->irq_pcs_link_n++;
 		dev_info(priv->device, "PCS Link %s\n",
-			 val & GMAC_AN_STATUS_LS ? "Up" : "Down");
+			 val & BMSR_LSTATUS ? "Up" : "Down");
 
-		phylink_pcs_change(&spcs->pcs, val & GMAC_AN_STATUS_LS);
+		phylink_pcs_change(&spcs->pcs, val & BMSR_LSTATUS);
 	}
 }
 
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h b/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h
index c4e6b242d390..13ee5bd6c788 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h
@@ -16,13 +16,6 @@
 
 /* PCS registers (AN/TBI/SGMII/RGMII) offsets */
 #define GMAC_AN_CTRL(x)		(x)		/* AN control */
-#define GMAC_AN_STATUS(x)	(x + 0x4)	/* AN status */
-
-/* ADV, LPA and EXP are only available for the TBI and RTBI interfaces */
-#define GMAC_ANE_ADV(x)		(x + 0x8)	/* ANE Advertisement */
-#define GMAC_ANE_LPA(x)		(x + 0xc)	/* ANE link partener ability */
-#define GMAC_ANE_EXP(x)		(x + 0x10)	/* ANE expansion */
-#define GMAC_TBI(x)		(x + 0x14)	/* TBI extend status */
 
 /* AN Configuration defines */
 #define GMAC_AN_CTRL_RAN	BIT_U32(9)	/* Restart Auto-Negotiation */
@@ -32,21 +25,6 @@
 #define GMAC_AN_CTRL_LR		BIT_U32(17)	/* Lock to Reference */
 #define GMAC_AN_CTRL_SGMRAL	BIT_U32(18)	/* SGMII RAL Control */
 
-/* AN Status defines */
-#define GMAC_AN_STATUS_LS	BIT_U32(2)	/* Link Status 0:down 1:up */
-#define GMAC_AN_STATUS_ANA	BIT_U32(3)	/* Auto-Negotiation Ability */
-#define GMAC_AN_STATUS_ANC	BIT_U32(5)	/* Auto-Negotiation Complete */
-#define GMAC_AN_STATUS_ES	BIT_U32(8)	/* Extended Status */
-
-/* ADV and LPA defines */
-#define GMAC_ANE_FD		BIT_U32(5)
-#define GMAC_ANE_HD		BIT_U32(6)
-#define GMAC_ANE_PSE		GENMASK_U32(8, 7)
-#define GMAC_ANE_PSE_SHIFT	7
-#define GMAC_ANE_RFE		GENMASK_U32(13, 12)
-#define GMAC_ANE_RFE_SHIFT	12
-#define GMAC_ANE_ACK		BIT_U32(14)
-
 struct stmmac_priv;
 
 struct stmmac_pcs {
-- 
2.47.3

[PATCH net-next 3/3] net: stmmac: handle integrated PCS phy_intf_sel separately

[Russell King (Oracle)]

The dwmac core has no support for SGMII without using its integrated
PCS. Thus, PHY_INTF_SEL_SGMII is only supported when this block is
present, and it makes no sense for stmmac_get_phy_intf_sel() to decode
this.

None of the platform glue users that use stmmac_get_phy_intf_sel()
directly accept PHY_INTF_SEL_SGMII as a valid mode.

Check whether a PCS will be used by the driver for the interface mode,
and if it is the integrated PCS, query the integrated PCS for the
phy_intf_sel_i value to use.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 15 ++++++++++++---
 drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.c  |  9 +++++++++
 drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h  |  2 ++
 3 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index a3c155cccd9b..b2b90c3c1c45 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -3159,8 +3159,6 @@ int stmmac_get_phy_intf_sel(phy_interface_t interface)
 		phy_intf_sel = PHY_INTF_SEL_GMII_MII;
 	else if (phy_interface_mode_is_rgmii(interface))
 		phy_intf_sel = PHY_INTF_SEL_RGMII;
-	else if (interface == PHY_INTERFACE_MODE_SGMII)
-		phy_intf_sel = PHY_INTF_SEL_SGMII;
 	else if (interface == PHY_INTERFACE_MODE_RMII)
 		phy_intf_sel = PHY_INTF_SEL_RMII;
 	else if (interface == PHY_INTERFACE_MODE_REVMII)
@@ -3174,13 +3172,24 @@ static int stmmac_prereset_configure(struct stmmac_priv *priv)
 {
 	struct plat_stmmacenet_data *plat_dat = priv->plat;
 	phy_interface_t interface;
+	struct phylink_pcs *pcs;
 	int phy_intf_sel, ret;
 
 	if (!plat_dat->set_phy_intf_sel)
 		return 0;
 
 	interface = plat_dat->phy_interface;
-	phy_intf_sel = stmmac_get_phy_intf_sel(interface);
+
+	/* Check whether this mode uses a PCS */
+	pcs = stmmac_mac_select_pcs(&priv->phylink_config, interface);
+	if (priv->integrated_pcs && pcs == &priv->integrated_pcs->pcs) {
+		/* Request the phy_intf_sel from the integrated PCS */
+		phy_intf_sel = stmmac_integrated_pcs_get_phy_intf_sel(pcs,
+								    interface);
+	} else {
+		phy_intf_sel = stmmac_get_phy_intf_sel(interface);
+	}
+
 	if (phy_intf_sel < 0) {
 		netdev_err(priv->dev,
 			   "failed to get phy_intf_sel for %s: %pe\n",
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.c
index e827c03ae932..88fa359ea716 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.c
@@ -81,6 +81,15 @@ void stmmac_integrated_pcs_irq(struct stmmac_priv *priv, u32 status,
 	}
 }
 
+int stmmac_integrated_pcs_get_phy_intf_sel(struct phylink_pcs *pcs,
+					   phy_interface_t interface)
+{
+	if (interface == PHY_INTERFACE_MODE_SGMII)
+		return PHY_INTF_SEL_SGMII;
+
+	return -EINVAL;
+}
+
 int stmmac_integrated_pcs_init(struct stmmac_priv *priv, unsigned int offset,
 			       u32 int_mask)
 {
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h b/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h
index 13ee5bd6c788..23bbd4f10bf8 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h
@@ -42,6 +42,8 @@ phylink_pcs_to_stmmac_pcs(struct phylink_pcs *pcs)
 
 void stmmac_integrated_pcs_irq(struct stmmac_priv *priv, u32 status,
 			       struct stmmac_extra_stats *x);
+int stmmac_integrated_pcs_get_phy_intf_sel(struct phylink_pcs *pcs,
+					   phy_interface_t interface);
 int stmmac_integrated_pcs_init(struct stmmac_priv *priv, unsigned int offset,
 			       u32 int_mask);
 
-- 
2.47.3

Re: [PATCH net-next 0/3] net: stmmac: pcs preparation

[Mohd Ayaan Anwar]

On Fri, Jan 30, 2026 at 11:10:12AM +0000, Russell King (Oracle) wrote:
> Hi,
> 
> These three patches prepare for the PCS changes, which, subject to
> Qualcomm testing, should be coming in the next cycle.
> 
>  .../net/ethernet/stmicro/stmmac/dwxgmac2_core.c    |  2 --
>  drivers/net/ethernet/stmicro/stmmac/stmmac_main.c  | 18 ++++++++++---
>  drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.c   | 31 +++++++++++++++++++---
>  drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h   | 24 ++---------------
>  4 files changed, 44 insertions(+), 31 deletions(-)
> 

No issues found on the QCS9100 Ride R3 board, so:

Tested-by: Mohd Ayaan Anwar <mohd.anwar@oss.qualcomm.com>

	Ayaan

Re: [PATCH net-next 0/3] net: stmmac: pcs preparation

[patchwork-bot+netdevbpf]

Hello:

This series was applied to netdev/net-next.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Fri, 30 Jan 2026 11:10:12 +0000 you wrote:
> Hi,
> 
> These three patches prepare for the PCS changes, which, subject to
> Qualcomm testing, should be coming in the next cycle.
> 
>  .../net/ethernet/stmicro/stmmac/dwxgmac2_core.c    |  2 --
>  drivers/net/ethernet/stmicro/stmmac/stmmac_main.c  | 18 ++++++++++---
>  drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.c   | 31 +++++++++++++++++++---
>  drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h   | 24 ++---------------
>  4 files changed, 44 insertions(+), 31 deletions(-)

Here is the summary with links:
  - [net-next,1/3] net: stmmac: clear half-duplex caps where unsupported
    https://git.kernel.org/netdev/net-next/c/83957d6cae5b
  - [net-next,2/3] net: stmmac: move most PCS register definitions to stmmac_pcs.c
    https://git.kernel.org/netdev/net-next/c/eb4a1fda2c2f
  - [net-next,3/3] net: stmmac: handle integrated PCS phy_intf_sel separately
    https://git.kernel.org/netdev/net-next/c/69a586e8866b

You are awesome, thank you!
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