[PATCH RFC net-next v2 0/7] net: stmmac: improve PCS support

[PATCH RFC net-next v2 0/7] net: stmmac: improve PCS support

[Russell King (Oracle)]

Resending this as the original RFC now conflicts with net-next.

This series is the next of the three part series sorting out the PCS
support in stmmac, building on part 2, which was posted yesterday:

	net: stmmac: qcom-ethqos: further serdes reorganisation

Similar patches have been posted previously. This series does away with
the common SerDes PHY support, instead using a flag to indicate whether
2500Mbps mode is supported (STMMAC_FLAG_SERDES_SUPPORTS_2500M.) At this
time, I have no plans to resurect the common SerDes PHY support - the
generic PHY layer implementations are just too random to consider that,
and I certainly do not want the extra work of fixing that.

I've also changed the last patch which prints warnings when qcom-ethqos
changes the PCS state - this will now indicate in a readable form
whether the ANE or SGMRAL bits have changed state, rather than having
to refer back to the definitions in the code or the databook.

I am hoping that - subject to this working for qcom-ethqos - we can
drop this last patch in the final submission, along with the
dwmac_ctrl_ane() and ethqos_pcs_set_inband() functions and associated
definitions. This will also mean that stmmac will finally be driving
the PCS correctly from a phylink point of view.

 drivers/net/ethernet/stmicro/stmmac/common.h       |   4 -
 .../ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c    |   1 +
 drivers/net/ethernet/stmicro/stmmac/dwmac1000.h    |  12 +-
 .../net/ethernet/stmicro/stmmac/dwmac1000_core.c   |  11 +-
 drivers/net/ethernet/stmicro/stmmac/dwmac4.h       |  10 +-
 drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c  |  10 +-
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c  |   8 +-
 drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.c   | 160 +++++++++++++++++++--
 drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h   |  29 +++-
 include/linux/stmmac.h                             |   1 +
 10 files changed, 200 insertions(+), 46 deletions(-)

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

[PATCH RFC net-next v2 1/7] net: stmmac: add BASE-X support to integrated PCS

[Russell King (Oracle)]

The integrated PCS supports 802.3z (BASE-X) modes when the Synopsys
IP is coupled with an appropriate SerDes to provide the electrical
interface. The PCS presents a TBI interface to the SerDes for this.
Thus, the BASE-X related registers are only present when TBI mode is
supported.

dwmac-qcom-ethqos added support for using 2.5G with the integrated PCS
by calling dwmac_ctrl_ane() directly.

Add support for the following to the integrated PCS:
- 1000BASE-X protocol unconditionally.
- 2500BASE-X if the coupled SerDes supports 2.5G speed.
- The above without autonegotiation.
- If the PCS supports TBI, then optional BASE-X autonegotiation for each
  of the above.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
---
 .../net/ethernet/stmicro/stmmac/stmmac_pcs.c  | 96 ++++++++++++++++++-
 .../net/ethernet/stmicro/stmmac/stmmac_pcs.h  |  1 +
 include/linux/stmmac.h                        |  1 +
 3 files changed, 95 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.c
index 88fa359ea716..e606dfb85f94 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.c
@@ -16,6 +16,27 @@
 #define GMAC_ANE_LPA	0x0c	/* ANE link partener ability */
 #define GMAC_TBI	0x14	/* TBI extend status */
 
+static unsigned int dwmac_integrated_pcs_inband_caps(struct phylink_pcs *pcs,
+						     phy_interface_t interface)
+{
+	struct stmmac_pcs *spcs = phylink_pcs_to_stmmac_pcs(pcs);
+	unsigned int ib_caps;
+
+	if (phy_interface_mode_is_8023z(interface)) {
+		ib_caps = LINK_INBAND_DISABLE;
+
+		/* If the PCS supports TBI/RTBI, then BASE-X negotiation is
+		 * supported.
+		 */
+		if (spcs->support_tbi_rtbi)
+			ib_caps |= LINK_INBAND_ENABLE;
+
+		return ib_caps;
+	}
+
+	return 0;
+}
+
 static int dwmac_integrated_pcs_enable(struct phylink_pcs *pcs)
 {
 	struct stmmac_pcs *spcs = phylink_pcs_to_stmmac_pcs(pcs);
@@ -36,7 +57,39 @@ static void dwmac_integrated_pcs_get_state(struct phylink_pcs *pcs,
 					   unsigned int neg_mode,
 					   struct phylink_link_state *state)
 {
-	state->link = false;
+	struct stmmac_pcs *spcs = phylink_pcs_to_stmmac_pcs(pcs);
+	u32 status, lpa;
+
+	status = readl(spcs->base + GMAC_AN_STATUS);
+
+	if (phy_interface_mode_is_8023z(state->interface)) {
+		/* For BASE-X modes, the PCS block supports the advertisement
+		 * and link partner advertisement registers using standard
+		 * 802.3 format. The status register also has the link status
+		 * and AN complete bits in the same bit location. This will
+		 * only be used when AN is enabled.
+		 */
+		lpa = readl(spcs->base + GMAC_ANE_LPA);
+
+		phylink_mii_c22_pcs_decode_state(state, neg_mode, status, lpa);
+	} else {
+		state->link = false;
+	}
+}
+
+static int dwmac_integrated_pcs_config_aneg(struct stmmac_pcs *spcs,
+					    phy_interface_t interface,
+					    const unsigned long *advertising)
+{
+	bool changed = false;
+	u32 adv;
+
+	adv = phylink_mii_c22_pcs_encode_advertisement(interface, advertising);
+	if (readl(spcs->base + GMAC_ANE_ADV) != adv)
+		changed = true;
+	writel(adv, spcs->base + GMAC_ANE_ADV);
+
+	return changed;
 }
 
 static int dwmac_integrated_pcs_config(struct phylink_pcs *pcs,
@@ -46,13 +99,28 @@ static int dwmac_integrated_pcs_config(struct phylink_pcs *pcs,
 				       bool permit_pause_to_mac)
 {
 	struct stmmac_pcs *spcs = phylink_pcs_to_stmmac_pcs(pcs);
+	bool changed = false, ane = true;
+
+	/* Only configure the advertisement and allow AN in BASE-X mode if
+	 * the core supports TBI/RTBI. AN will be filtered out by via phylink
+	 * and the .pcs_inband_caps() method above.
+	 */
+	if (phy_interface_mode_is_8023z(interface) &&
+	    spcs->support_tbi_rtbi) {
+		ane = neg_mode == PHYLINK_PCS_NEG_INBAND_ENABLED;
+
+		changed = dwmac_integrated_pcs_config_aneg(spcs, interface,
+							   advertising);
+	}
 
-	dwmac_ctrl_ane(spcs->base, 0, 1, spcs->priv->hw->reverse_sgmii_enable);
+	dwmac_ctrl_ane(spcs->base, 0, ane,
+		       spcs->priv->hw->reverse_sgmii_enable);
 
-	return 0;
+	return changed;
 }
 
 static const struct phylink_pcs_ops dwmac_integrated_pcs_ops = {
+	.pcs_inband_caps = dwmac_integrated_pcs_inband_caps,
 	.pcs_enable = dwmac_integrated_pcs_enable,
 	.pcs_disable = dwmac_integrated_pcs_disable,
 	.pcs_get_state = dwmac_integrated_pcs_get_state,
@@ -84,9 +152,18 @@ 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)
 {
+	struct stmmac_pcs *spcs = phylink_pcs_to_stmmac_pcs(pcs);
+
 	if (interface == PHY_INTERFACE_MODE_SGMII)
 		return PHY_INTF_SEL_SGMII;
 
+	if (phy_interface_mode_is_8023z(interface)) {
+		if (spcs->support_tbi_rtbi)
+			return PHY_INTF_SEL_TBI;
+		else
+			return PHY_INTF_SEL_SGMII;
+	}
+
 	return -EINVAL;
 }
 
@@ -104,7 +181,20 @@ int stmmac_integrated_pcs_init(struct stmmac_priv *priv, unsigned int offset,
 	spcs->int_mask = int_mask;
 	spcs->pcs.ops = &dwmac_integrated_pcs_ops;
 
+	/* If the PCS supports extended status, then it supports BASE-X AN
+	 * with a TBI interface to the SerDes. Otherwise, we can support
+	 * BASE-X without AN using SGMII, which is required for qcom-ethqos.
+	 */
+	if (readl(spcs->base + GMAC_AN_STATUS) & BMSR_ESTATEN)
+		spcs->support_tbi_rtbi = true;
+
 	__set_bit(PHY_INTERFACE_MODE_SGMII, spcs->pcs.supported_interfaces);
+	__set_bit(PHY_INTERFACE_MODE_1000BASEX, spcs->pcs.supported_interfaces);
+
+	/* Only allow 2500BASE-X if the SerDes has support. */
+	if (priv->plat->flags & STMMAC_FLAG_SERDES_SUPPORTS_2500M)
+		__set_bit(PHY_INTERFACE_MODE_2500BASEX,
+			  spcs->pcs.supported_interfaces);
 
 	priv->integrated_pcs = spcs;
 
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h b/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h
index 23bbd4f10bf8..12ea87792fcb 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h
@@ -32,6 +32,7 @@ struct stmmac_pcs {
 	void __iomem *base;
 	u32 int_mask;
 	struct phylink_pcs pcs;
+	bool support_tbi_rtbi;
 };
 
 static inline struct stmmac_pcs *
diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h
index 2fc169c7117e..3a99c4ef420c 100644
--- a/include/linux/stmmac.h
+++ b/include/linux/stmmac.h
@@ -192,6 +192,7 @@ enum dwmac_core_type {
 #define STMMAC_FLAG_EN_TX_LPI_CLK_PHY_CAP	BIT(12)
 #define STMMAC_FLAG_HWTSTAMP_CORRECT_LATENCY	BIT(13)
 #define STMMAC_FLAG_KEEP_PREAMBLE_BEFORE_SFD	BIT(14)
+#define STMMAC_FLAG_SERDES_SUPPORTS_2500M	BIT(15)
 
 struct mac_device_info;
 
-- 
2.47.3

Re: [PATCH RFC net-next v2 1/7] net: stmmac: add BASE-X support to integrated PCS

[Maxime Chevallier]

Hello Russell,

On 04/03/2026 09:48, Russell King (Oracle) wrote:
> The integrated PCS supports 802.3z (BASE-X) modes when the Synopsys
> IP is coupled with an appropriate SerDes to provide the electrical
> interface. The PCS presents a TBI interface to the SerDes for this.
> Thus, the BASE-X related registers are only present when TBI mode is
> supported.
> 
> dwmac-qcom-ethqos added support for using 2.5G with the integrated PCS
> by calling dwmac_ctrl_ane() directly.
> 
> Add support for the following to the integrated PCS:
> - 1000BASE-X protocol unconditionally.
> - 2500BASE-X if the coupled SerDes supports 2.5G speed.
> - The above without autonegotiation.
> - If the PCS supports TBI, then optional BASE-X autonegotiation for each
>   of the above.
> 
> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

Haven't tested ofc, but this patch looks good to me (well, my knowledge
about 1000BaseX vs SGMII w.r.t aneg mostly comes from you in the first
place).

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

Maxime
> ---
>  .../net/ethernet/stmicro/stmmac/stmmac_pcs.c  | 96 ++++++++++++++++++-
>  .../net/ethernet/stmicro/stmmac/stmmac_pcs.h  |  1 +
>  include/linux/stmmac.h                        |  1 +
>  3 files changed, 95 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.c
> index 88fa359ea716..e606dfb85f94 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.c
> @@ -16,6 +16,27 @@
>  #define GMAC_ANE_LPA	0x0c	/* ANE link partener ability */
>  #define GMAC_TBI	0x14	/* TBI extend status */
>  
> +static unsigned int dwmac_integrated_pcs_inband_caps(struct phylink_pcs *pcs,
> +						     phy_interface_t interface)
> +{
> +	struct stmmac_pcs *spcs = phylink_pcs_to_stmmac_pcs(pcs);
> +	unsigned int ib_caps;
> +
> +	if (phy_interface_mode_is_8023z(interface)) {
> +		ib_caps = LINK_INBAND_DISABLE;
> +
> +		/* If the PCS supports TBI/RTBI, then BASE-X negotiation is
> +		 * supported.
> +		 */
> +		if (spcs->support_tbi_rtbi)
> +			ib_caps |= LINK_INBAND_ENABLE;
> +
> +		return ib_caps;
> +	}
> +
> +	return 0;
> +}
> +
>  static int dwmac_integrated_pcs_enable(struct phylink_pcs *pcs)
>  {
>  	struct stmmac_pcs *spcs = phylink_pcs_to_stmmac_pcs(pcs);
> @@ -36,7 +57,39 @@ static void dwmac_integrated_pcs_get_state(struct phylink_pcs *pcs,
>  					   unsigned int neg_mode,
>  					   struct phylink_link_state *state)
>  {
> -	state->link = false;
> +	struct stmmac_pcs *spcs = phylink_pcs_to_stmmac_pcs(pcs);
> +	u32 status, lpa;
> +
> +	status = readl(spcs->base + GMAC_AN_STATUS);
> +
> +	if (phy_interface_mode_is_8023z(state->interface)) {
> +		/* For BASE-X modes, the PCS block supports the advertisement
> +		 * and link partner advertisement registers using standard
> +		 * 802.3 format. The status register also has the link status
> +		 * and AN complete bits in the same bit location. This will
> +		 * only be used when AN is enabled.
> +		 */
> +		lpa = readl(spcs->base + GMAC_ANE_LPA);
> +
> +		phylink_mii_c22_pcs_decode_state(state, neg_mode, status, lpa);
> +	} else {
> +		state->link = false;
> +	}
> +}
> +
> +static int dwmac_integrated_pcs_config_aneg(struct stmmac_pcs *spcs,
> +					    phy_interface_t interface,
> +					    const unsigned long *advertising)
> +{
> +	bool changed = false;
> +	u32 adv;
> +
> +	adv = phylink_mii_c22_pcs_encode_advertisement(interface, advertising);
> +	if (readl(spcs->base + GMAC_ANE_ADV) != adv)
> +		changed = true;
> +	writel(adv, spcs->base + GMAC_ANE_ADV);
> +
> +	return changed;
>  }
>  
>  static int dwmac_integrated_pcs_config(struct phylink_pcs *pcs,
> @@ -46,13 +99,28 @@ static int dwmac_integrated_pcs_config(struct phylink_pcs *pcs,
>  				       bool permit_pause_to_mac)
>  {
>  	struct stmmac_pcs *spcs = phylink_pcs_to_stmmac_pcs(pcs);
> +	bool changed = false, ane = true;
> +
> +	/* Only configure the advertisement and allow AN in BASE-X mode if
> +	 * the core supports TBI/RTBI. AN will be filtered out by via phylink
> +	 * and the .pcs_inband_caps() method above.
> +	 */
> +	if (phy_interface_mode_is_8023z(interface) &&
> +	    spcs->support_tbi_rtbi) {
> +		ane = neg_mode == PHYLINK_PCS_NEG_INBAND_ENABLED;
> +
> +		changed = dwmac_integrated_pcs_config_aneg(spcs, interface,
> +							   advertising);
> +	}
>  
> -	dwmac_ctrl_ane(spcs->base, 0, 1, spcs->priv->hw->reverse_sgmii_enable);
> +	dwmac_ctrl_ane(spcs->base, 0, ane,
> +		       spcs->priv->hw->reverse_sgmii_enable);
>  
> -	return 0;
> +	return changed;
>  }
>  
>  static const struct phylink_pcs_ops dwmac_integrated_pcs_ops = {
> +	.pcs_inband_caps = dwmac_integrated_pcs_inband_caps,
>  	.pcs_enable = dwmac_integrated_pcs_enable,
>  	.pcs_disable = dwmac_integrated_pcs_disable,
>  	.pcs_get_state = dwmac_integrated_pcs_get_state,
> @@ -84,9 +152,18 @@ 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)
>  {
> +	struct stmmac_pcs *spcs = phylink_pcs_to_stmmac_pcs(pcs);
> +
>  	if (interface == PHY_INTERFACE_MODE_SGMII)
>  		return PHY_INTF_SEL_SGMII;
>  
> +	if (phy_interface_mode_is_8023z(interface)) {
> +		if (spcs->support_tbi_rtbi)
> +			return PHY_INTF_SEL_TBI;
> +		else
> +			return PHY_INTF_SEL_SGMII;
> +	}
> +
>  	return -EINVAL;
>  }
>  
> @@ -104,7 +181,20 @@ int stmmac_integrated_pcs_init(struct stmmac_priv *priv, unsigned int offset,
>  	spcs->int_mask = int_mask;
>  	spcs->pcs.ops = &dwmac_integrated_pcs_ops;
>  
> +	/* If the PCS supports extended status, then it supports BASE-X AN
> +	 * with a TBI interface to the SerDes. Otherwise, we can support
> +	 * BASE-X without AN using SGMII, which is required for qcom-ethqos.
> +	 */
> +	if (readl(spcs->base + GMAC_AN_STATUS) & BMSR_ESTATEN)
> +		spcs->support_tbi_rtbi = true;
> +
>  	__set_bit(PHY_INTERFACE_MODE_SGMII, spcs->pcs.supported_interfaces);
> +	__set_bit(PHY_INTERFACE_MODE_1000BASEX, spcs->pcs.supported_interfaces);
> +
> +	/* Only allow 2500BASE-X if the SerDes has support. */
> +	if (priv->plat->flags & STMMAC_FLAG_SERDES_SUPPORTS_2500M)
> +		__set_bit(PHY_INTERFACE_MODE_2500BASEX,
> +			  spcs->pcs.supported_interfaces);
>  
>  	priv->integrated_pcs = spcs;
>  
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h b/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h
> index 23bbd4f10bf8..12ea87792fcb 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h
> @@ -32,6 +32,7 @@ struct stmmac_pcs {
>  	void __iomem *base;
>  	u32 int_mask;
>  	struct phylink_pcs pcs;
> +	bool support_tbi_rtbi;
>  };
>  
>  static inline struct stmmac_pcs *
> diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h
> index 2fc169c7117e..3a99c4ef420c 100644
> --- a/include/linux/stmmac.h
> +++ b/include/linux/stmmac.h
> @@ -192,6 +192,7 @@ enum dwmac_core_type {
>  #define STMMAC_FLAG_EN_TX_LPI_CLK_PHY_CAP	BIT(12)
>  #define STMMAC_FLAG_HWTSTAMP_CORRECT_LATENCY	BIT(13)
>  #define STMMAC_FLAG_KEEP_PREAMBLE_BEFORE_SFD	BIT(14)
> +#define STMMAC_FLAG_SERDES_SUPPORTS_2500M	BIT(15)
>  
>  struct mac_device_info;
>  

[PATCH RFC net-next v2 2/7] net: stmmac: qcom-ethqos: enable 2500BASE-X

[Russell King (Oracle)]

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
---
 drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c
index cb1c074c2053..f4b63544895e 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c
@@ -828,6 +828,7 @@ static int qcom_ethqos_probe(struct platform_device *pdev)
 	if (ethqos->serdes_phy) {
 		plat_dat->serdes_powerup = qcom_ethqos_serdes_powerup;
 		plat_dat->serdes_powerdown  = qcom_ethqos_serdes_powerdown;
+		plat_dat->flags |= STMMAC_FLAG_SERDES_SUPPORTS_2500M;
 	}
 
 	/* Enable TSO on queue0 and enable TBS on rest of the queues */
-- 
2.47.3

[PATCH RFC net-next v2 3/7] net: stmmac: use integrated PCS for BASE-X modes

[Russell King (Oracle)]

dwmac-qcom-ethqos supports SGMII and 2500BASE-X using the integrated
PCS, so we need to expand the PCS support to include support for
BASE-X modes.

Add support to the prereset configuration to detect 2500BASE-X, and
arrange for stmmac_mac_select_pcs() to return the integrated PCS if
its supported_interfaces bitmap reports support for the interface mode.

This results in priv->hw->pcs now being write-only, so remove it.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
---
 drivers/net/ethernet/stmicro/stmmac/common.h      | 4 ----
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 8 ++------
 2 files changed, 2 insertions(+), 10 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/common.h b/drivers/net/ethernet/stmicro/stmmac/common.h
index 42a48f655849..91116acf3273 100644
--- a/drivers/net/ethernet/stmicro/stmmac/common.h
+++ b/drivers/net/ethernet/stmicro/stmmac/common.h
@@ -277,9 +277,6 @@ struct stmmac_safety_stats {
 #define FLOW_TX		2
 #define FLOW_AUTO	(FLOW_TX | FLOW_RX)
 
-/* PCS defines */
-#define STMMAC_PCS_SGMII	(1 << 1)
-
 #define SF_DMA_MODE 1		/* DMA STORE-AND-FORWARD Operation Mode */
 
 /* DMA HW feature register fields */
@@ -634,7 +631,6 @@ struct mac_device_info {
 	unsigned int unicast_filter_entries;
 	unsigned int mcast_bits_log2;
 	unsigned int rx_csum;
-	unsigned int pcs;
 	unsigned int num_vlan;
 	u32 vlan_filter[32];
 	bool vlan_fail_q_en;
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 029e9b518160..2e7edc3e82f2 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -945,11 +945,8 @@ static struct phylink_pcs *stmmac_mac_select_pcs(struct phylink_config *config,
 			return pcs;
 	}
 
-	/* The PCS control register is only relevant for SGMII, TBI and RTBI
-	 * modes. We no longer support TBI or RTBI, so only configure this
-	 * register when operating in SGMII mode with the integrated PCS.
-	 */
-	if (priv->hw->pcs & STMMAC_PCS_SGMII && priv->integrated_pcs)
+	if (priv->integrated_pcs &&
+	    test_bit(interface, priv->integrated_pcs->pcs.supported_interfaces))
 		return &priv->integrated_pcs->pcs;
 
 	return NULL;
@@ -1208,7 +1205,6 @@ static void stmmac_check_pcs_mode(struct stmmac_priv *priv)
 
 	if (priv->dma_cap.pcs && interface == PHY_INTERFACE_MODE_SGMII) {
 		netdev_dbg(priv->dev, "PCS SGMII support enabled\n");
-		priv->hw->pcs = STMMAC_PCS_SGMII;
 
 		switch (speed) {
 		case SPEED_10:
-- 
2.47.3

Re: [PATCH RFC net-next v2 3/7] net: stmmac: use integrated PCS for BASE-X modes

[Maxime Chevallier]

Hi Russell,

On 04/03/2026 09:49, Russell King (Oracle) wrote:
> dwmac-qcom-ethqos supports SGMII and 2500BASE-X using the integrated
> PCS, so we need to expand the PCS support to include support for
> BASE-X modes.
> 
> Add support to the prereset configuration to detect 2500BASE-X, and
> arrange for stmmac_mac_select_pcs() to return the integrated PCS if
> its supported_interfaces bitmap reports support for the interface mode.
> 
> This results in priv->hw->pcs now being write-only, so remove it.
> 
> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

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

Maxime

> ---
>  drivers/net/ethernet/stmicro/stmmac/common.h      | 4 ----
>  drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 8 ++------
>  2 files changed, 2 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/net/ethernet/stmicro/stmmac/common.h b/drivers/net/ethernet/stmicro/stmmac/common.h
> index 42a48f655849..91116acf3273 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/common.h
> +++ b/drivers/net/ethernet/stmicro/stmmac/common.h
> @@ -277,9 +277,6 @@ struct stmmac_safety_stats {
>  #define FLOW_TX		2
>  #define FLOW_AUTO	(FLOW_TX | FLOW_RX)
>  
> -/* PCS defines */
> -#define STMMAC_PCS_SGMII	(1 << 1)
> -
>  #define SF_DMA_MODE 1		/* DMA STORE-AND-FORWARD Operation Mode */
>  
>  /* DMA HW feature register fields */
> @@ -634,7 +631,6 @@ struct mac_device_info {
>  	unsigned int unicast_filter_entries;
>  	unsigned int mcast_bits_log2;
>  	unsigned int rx_csum;
> -	unsigned int pcs;
>  	unsigned int num_vlan;
>  	u32 vlan_filter[32];
>  	bool vlan_fail_q_en;
> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> index 029e9b518160..2e7edc3e82f2 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
> @@ -945,11 +945,8 @@ static struct phylink_pcs *stmmac_mac_select_pcs(struct phylink_config *config,
>  			return pcs;
>  	}
>  
> -	/* The PCS control register is only relevant for SGMII, TBI and RTBI
> -	 * modes. We no longer support TBI or RTBI, so only configure this
> -	 * register when operating in SGMII mode with the integrated PCS.
> -	 */
> -	if (priv->hw->pcs & STMMAC_PCS_SGMII && priv->integrated_pcs)
> +	if (priv->integrated_pcs &&
> +	    test_bit(interface, priv->integrated_pcs->pcs.supported_interfaces))
>  		return &priv->integrated_pcs->pcs;
>  
>  	return NULL;
> @@ -1208,7 +1205,6 @@ static void stmmac_check_pcs_mode(struct stmmac_priv *priv)
>  
>  	if (priv->dma_cap.pcs && interface == PHY_INTERFACE_MODE_SGMII) {
>  		netdev_dbg(priv->dev, "PCS SGMII support enabled\n");
> -		priv->hw->pcs = STMMAC_PCS_SGMII;
>  
>  		switch (speed) {
>  		case SPEED_10:

[PATCH RFC net-next v2 4/7] net: stmmac: add struct stmmac_pcs_info

[Russell King (Oracle)]

We need to describe one more register (offset and field bitmask) to
the PCS code. Move the existing PCS offset and interrupt enable bits
to a new struct and pass that in to stmmac_integrated_pcs_init().

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
---
 drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c | 9 ++++++---
 drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c    | 8 ++++++--
 drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.c     | 8 ++++----
 drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h     | 9 +++++++--
 4 files changed, 23 insertions(+), 11 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c
index af566636fad9..a3ef237de1b8 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c
@@ -22,14 +22,17 @@
 #include "stmmac_ptp.h"
 #include "dwmac1000.h"
 
+static const struct stmmac_pcs_info dwmac1000_pcs_info = {
+	.pcs_offset = GMAC_PCS_BASE,
+	.int_mask = GMAC_INT_DISABLE_PCSLINK | GMAC_INT_DISABLE_PCSAN,
+};
+
 static int dwmac1000_pcs_init(struct stmmac_priv *priv)
 {
 	if (!priv->dma_cap.pcs)
 		return 0;
 
-	return stmmac_integrated_pcs_init(priv, GMAC_PCS_BASE,
-					  GMAC_INT_DISABLE_PCSLINK |
-					  GMAC_INT_DISABLE_PCSAN);
+	return stmmac_integrated_pcs_init(priv, &dwmac1000_pcs_info);
 }
 
 static void dwmac1000_core_init(struct mac_device_info *hw,
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c b/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
index 623868afe93d..7f4949229288 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
@@ -22,13 +22,17 @@
 #include "dwmac4.h"
 #include "dwmac5.h"
 
+static const struct stmmac_pcs_info dwmac4_pcs_info = {
+	.pcs_offset = GMAC_PCS_BASE,
+	.int_mask = GMAC_INT_PCS_LINK | GMAC_INT_PCS_ANE,
+};
+
 static int dwmac4_pcs_init(struct stmmac_priv *priv)
 {
 	if (!priv->dma_cap.pcs)
 		return 0;
 
-	return stmmac_integrated_pcs_init(priv, GMAC_PCS_BASE,
-					  GMAC_INT_PCS_LINK | GMAC_INT_PCS_ANE);
+	return stmmac_integrated_pcs_init(priv, &dwmac4_pcs_info);
 }
 
 static void dwmac4_core_init(struct mac_device_info *hw,
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.c
index e606dfb85f94..77a83e415597 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.c
@@ -167,8 +167,8 @@ int stmmac_integrated_pcs_get_phy_intf_sel(struct phylink_pcs *pcs,
 	return -EINVAL;
 }
 
-int stmmac_integrated_pcs_init(struct stmmac_priv *priv, unsigned int offset,
-			       u32 int_mask)
+int stmmac_integrated_pcs_init(struct stmmac_priv *priv,
+			       const struct stmmac_pcs_info *pcs_info)
 {
 	struct stmmac_pcs *spcs;
 
@@ -177,8 +177,8 @@ int stmmac_integrated_pcs_init(struct stmmac_priv *priv, unsigned int offset,
 		return -ENOMEM;
 
 	spcs->priv = priv;
-	spcs->base = priv->ioaddr + offset;
-	spcs->int_mask = int_mask;
+	spcs->base = priv->ioaddr + pcs_info->pcs_offset;
+	spcs->int_mask = pcs_info->int_mask;
 	spcs->pcs.ops = &dwmac_integrated_pcs_ops;
 
 	/* If the PCS supports extended status, then it supports BASE-X AN
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h b/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h
index 12ea87792fcb..f3dada71e381 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h
@@ -27,6 +27,11 @@
 
 struct stmmac_priv;
 
+struct stmmac_pcs_info {
+	unsigned int pcs_offset;
+	u32 int_mask;
+};
+
 struct stmmac_pcs {
 	struct stmmac_priv *priv;
 	void __iomem *base;
@@ -45,8 +50,8 @@ 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);
+int stmmac_integrated_pcs_init(struct stmmac_priv *priv,
+			       const struct stmmac_pcs_info *pcs_info);
 
 /**
  * dwmac_ctrl_ane - To program the AN Control Register.
-- 
2.47.3

[PATCH RFC net-next v2 5/7] net: stmmac: add support for reading inband SGMII status

[Russell King (Oracle)]

Report the link, speed and duplex for SGMII links, read from the
SGMII, RGMII and SMII status and control register.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
---
rfc->v1: fix setting SGMII's link status - depend on both link status.
v2:
 - fill in rsgmii offset and status fields in dwmac cores
 - rename new GMAC_RGSMIII_xxx constants to GMAC_RGSMII_xxx
---
 .../net/ethernet/stmicro/stmmac/dwmac1000.h   | 12 +----
 .../ethernet/stmicro/stmmac/dwmac1000_core.c  |  2 +
 drivers/net/ethernet/stmicro/stmmac/dwmac4.h  | 10 +---
 .../net/ethernet/stmicro/stmmac/dwmac4_core.c |  2 +
 .../net/ethernet/stmicro/stmmac/stmmac_pcs.c  | 46 ++++++++++++++++++-
 .../net/ethernet/stmicro/stmmac/stmmac_pcs.h  |  4 ++
 6 files changed, 54 insertions(+), 22 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac1000.h b/drivers/net/ethernet/stmicro/stmmac/dwmac1000.h
index 9fe639fb06bb..1de1f929d61c 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac1000.h
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac1000.h
@@ -70,18 +70,8 @@ enum power_event {
 #define GMAC_RGSMIIIS		0x000000d8	/* RGMII/SMII status */
 
 /* SGMII/RGMII status register */
-#define GMAC_RGSMIIIS_LNKMODE		BIT(0)
-#define GMAC_RGSMIIIS_SPEED		GENMASK(2, 1)
-#define GMAC_RGSMIIIS_LNKSTS		BIT(3)
-#define GMAC_RGSMIIIS_JABTO		BIT(4)
-#define GMAC_RGSMIIIS_FALSECARDET	BIT(5)
+#define GMAC_RSGMIIIS_MASK		GENMASK(15, 0)
 #define GMAC_RGSMIIIS_SMIDRXS		BIT(16)
-/* LNKMOD */
-#define GMAC_RGSMIIIS_LNKMOD_MASK	0x1
-/* LNKSPEED */
-#define GMAC_RGSMIIIS_SPEED_125		0x2
-#define GMAC_RGSMIIIS_SPEED_25		0x1
-#define GMAC_RGSMIIIS_SPEED_2_5		0x0
 
 /* GMAC Configuration defines */
 #define GMAC_CONTROL_2K 0x08000000	/* IEEE 802.3as 2K packets */
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c
index a3ef237de1b8..31f6ac5432f2 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_core.c
@@ -24,6 +24,8 @@
 
 static const struct stmmac_pcs_info dwmac1000_pcs_info = {
 	.pcs_offset = GMAC_PCS_BASE,
+	.rgsmii_offset = GMAC_RGSMIIIS,
+	.rgsmii_status_mask = GMAC_RSGMIIIS_MASK,
 	.int_mask = GMAC_INT_DISABLE_PCSLINK | GMAC_INT_DISABLE_PCSAN,
 };
 
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4.h b/drivers/net/ethernet/stmicro/stmmac/dwmac4.h
index d797d936aee1..ffcd036d4c02 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4.h
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4.h
@@ -470,15 +470,7 @@ static inline u32 mtl_low_credx_base_addr(const struct dwmac4_addrs *addrs,
 #define GMAC_PHYIF_CTRLSTATUS_TC		BIT(0)
 #define GMAC_PHYIF_CTRLSTATUS_LUD		BIT(1)
 #define GMAC_PHYIF_CTRLSTATUS_SMIDRXS		BIT(4)
-#define GMAC_PHYIF_CTRLSTATUS_LNKMOD		BIT(16)
-#define GMAC_PHYIF_CTRLSTATUS_SPEED		GENMASK(18, 17)
-#define GMAC_PHYIF_CTRLSTATUS_LNKSTS		BIT(19)
-#define GMAC_PHYIF_CTRLSTATUS_JABTO		BIT(20)
-#define GMAC_PHYIF_CTRLSTATUS_FALSECARDET	BIT(21)
-/* LNKSPEED */
-#define GMAC_PHYIF_CTRLSTATUS_SPEED_125		0x2
-#define GMAC_PHYIF_CTRLSTATUS_SPEED_25		0x1
-#define GMAC_PHYIF_CTRLSTATUS_SPEED_2_5		0x0
+#define GMAC_PHYIF_CTRLSTATUS_RSGMII_MASK	GENMASK(31, 16)
 
 extern const struct stmmac_dma_ops dwmac4_dma_ops;
 extern const struct stmmac_dma_ops dwmac410_dma_ops;
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c b/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
index 7f4949229288..ced2cd98cc54 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_core.c
@@ -24,6 +24,8 @@
 
 static const struct stmmac_pcs_info dwmac4_pcs_info = {
 	.pcs_offset = GMAC_PCS_BASE,
+	.rgsmii_offset = GMAC_PHYIF_CONTROL_STATUS,
+	.rgsmii_status_mask = GMAC_PHYIF_CTRLSTATUS_RSGMII_MASK,
 	.int_mask = GMAC_INT_PCS_LINK | GMAC_INT_PCS_ANE,
 };
 
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.c
index 77a83e415597..ba0cf51e67f7 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.c
@@ -16,6 +16,16 @@
 #define GMAC_ANE_LPA	0x0c	/* ANE link partener ability */
 #define GMAC_TBI	0x14	/* TBI extend status */
 
+/*
+ * RGSMII status bitfield definitions.
+ */
+#define GMAC_RGSMII_LNKMOD		BIT(0)
+#define GMAC_RGSMII_SPEED_MASK		GENMASK(2, 1)
+#define GMAC_RGSMII_SPEED_125		2
+#define GMAC_RGSMII_SPEED_25		1
+#define GMAC_RGSMII_SPEED_2_5		0
+#define GMAC_RGSMII_LNKSTS		BIT(3)
+
 static unsigned int dwmac_integrated_pcs_inband_caps(struct phylink_pcs *pcs,
 						     phy_interface_t interface)
 {
@@ -58,7 +68,7 @@ static void dwmac_integrated_pcs_get_state(struct phylink_pcs *pcs,
 					   struct phylink_link_state *state)
 {
 	struct stmmac_pcs *spcs = phylink_pcs_to_stmmac_pcs(pcs);
-	u32 status, lpa;
+	u32 status, lpa, rgsmii;
 
 	status = readl(spcs->base + GMAC_AN_STATUS);
 
@@ -73,7 +83,37 @@ static void dwmac_integrated_pcs_get_state(struct phylink_pcs *pcs,
 
 		phylink_mii_c22_pcs_decode_state(state, neg_mode, status, lpa);
 	} else {
-		state->link = false;
+		rgsmii = field_get(spcs->rgsmii_status_mask,
+				   readl(spcs->rgsmii));
+
+		state->link = status & BMSR_LSTATUS &&
+			      rgsmii & GMAC_RGSMII_LNKSTS;
+
+		if (state->link && neg_mode == PHYLINK_PCS_NEG_INBAND_ENABLED) {
+			/* FIXME: fill in speed and duplex. This requires the
+			 * contents of the dwmac1000 GMAC_RGSMIIS or dwmac4
+			 * GMAC_PHYIF_CONTROL_STATUS register.
+			 */
+			state->duplex = rgsmii & GMAC_RGSMII_LNKMOD ?
+					DUPLEX_FULL : DUPLEX_HALF;
+			switch (FIELD_GET(GMAC_RGSMII_SPEED_MASK, rgsmii)) {
+			case GMAC_RGSMII_SPEED_2_5:
+				state->speed = SPEED_10;
+				break;
+
+			case GMAC_RGSMII_SPEED_25:
+				state->speed = SPEED_100;
+				break;
+
+			case GMAC_RGSMII_SPEED_125:
+				state->speed = SPEED_1000;
+				break;
+
+			default:
+				state->link = false;
+				break;
+			}
+		}
 	}
 }
 
@@ -178,6 +218,8 @@ int stmmac_integrated_pcs_init(struct stmmac_priv *priv,
 
 	spcs->priv = priv;
 	spcs->base = priv->ioaddr + pcs_info->pcs_offset;
+	spcs->rgsmii = priv->ioaddr + pcs_info->rgsmii_offset;
+	spcs->rgsmii_status_mask = pcs_info->rgsmii_status_mask;
 	spcs->int_mask = pcs_info->int_mask;
 	spcs->pcs.ops = &dwmac_integrated_pcs_ops;
 
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h b/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h
index f3dada71e381..b2b12d34b3dd 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h
@@ -29,12 +29,16 @@ struct stmmac_priv;
 
 struct stmmac_pcs_info {
 	unsigned int pcs_offset;
+	unsigned int rgsmii_offset;
+	u32 rgsmii_status_mask;
 	u32 int_mask;
 };
 
 struct stmmac_pcs {
 	struct stmmac_priv *priv;
 	void __iomem *base;
+	void __iomem *rgsmii;
+	u32 rgsmii_status_mask;
 	u32 int_mask;
 	struct phylink_pcs pcs;
 	bool support_tbi_rtbi;
-- 
2.47.3

[PATCH RFC net-next v2 6/7] net: stmmac: configure SGMII AN control according to phylink

[Russell King (Oracle)]

Provide phylink with the integrated PCS autonegotiation capabilities,
and configure the PCS's AN settings according to phylink's requested
requirements.

This may cause regressions.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
---
 .../net/ethernet/stmicro/stmmac/stmmac_pcs.c  | 24 +++++++++++++------
 1 file changed, 17 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.c
index ba0cf51e67f7..0f9616fad4ef 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.c
@@ -32,6 +32,9 @@ static unsigned int dwmac_integrated_pcs_inband_caps(struct phylink_pcs *pcs,
 	struct stmmac_pcs *spcs = phylink_pcs_to_stmmac_pcs(pcs);
 	unsigned int ib_caps;
 
+	if (interface == PHY_INTERFACE_MODE_SGMII)
+		return LINK_INBAND_ENABLE | LINK_INBAND_DISABLE;
+
 	if (phy_interface_mode_is_8023z(interface)) {
 		ib_caps = LINK_INBAND_DISABLE;
 
@@ -139,22 +142,29 @@ static int dwmac_integrated_pcs_config(struct phylink_pcs *pcs,
 				       bool permit_pause_to_mac)
 {
 	struct stmmac_pcs *spcs = phylink_pcs_to_stmmac_pcs(pcs);
-	bool changed = false, ane = true;
+	void __iomem *an_control = spcs->base + GMAC_AN_CTRL(0);
+	bool ane, changed = false;
+	u32 ctrl;
+
+	ane = neg_mode == PHYLINK_PCS_NEG_INBAND_ENABLED;
 
 	/* Only configure the advertisement and allow AN in BASE-X mode if
 	 * the core supports TBI/RTBI. AN will be filtered out by via phylink
 	 * and the .pcs_inband_caps() method above.
 	 */
 	if (phy_interface_mode_is_8023z(interface) &&
-	    spcs->support_tbi_rtbi) {
-		ane = neg_mode == PHYLINK_PCS_NEG_INBAND_ENABLED;
-
+	    spcs->support_tbi_rtbi)
 		changed = dwmac_integrated_pcs_config_aneg(spcs, interface,
 							   advertising);
-	}
 
-	dwmac_ctrl_ane(spcs->base, 0, ane,
-		       spcs->priv->hw->reverse_sgmii_enable);
+	ctrl = readl(an_control) & ~(GMAC_AN_CTRL_ANE | GMAC_AN_CTRL_SGMRAL);
+	if (spcs->priv->hw->reverse_sgmii_enable)
+		ctrl |= GMAC_AN_CTRL_SGMRAL | GMAC_AN_CTRL_ANE;
+	else if (ane)
+		ctrl |= GMAC_AN_CTRL_ANE;
+	else
+		ctrl |= GMAC_AN_CTRL_SGMRAL;
+	writel(ctrl, an_control);
 
 	return changed;
 }
-- 
2.47.3

[PATCH RFC net-next v2 7/7] net: stmmac: report PCS configuration changes

[Russell King (Oracle)]

Report if/when qcom-ethqos changes the PCS configuration. With phylink
now setting the PCS configuration, there should be no need for drivers
to change this.

Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h b/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h
index b2b12d34b3dd..83651292578c 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_pcs.h
@@ -71,6 +71,7 @@ static inline void dwmac_ctrl_ane(void __iomem *ioaddr, u32 reg, bool ane,
 				  bool srgmi_ral)
 {
 	u32 value = readl(ioaddr + GMAC_AN_CTRL(reg));
+	u32 old = value, diff;
 
 	/* Enable and restart the Auto-Negotiation */
 	if (ane)
@@ -84,6 +85,20 @@ static inline void dwmac_ctrl_ane(void __iomem *ioaddr, u32 reg, bool ane,
 	if (srgmi_ral)
 		value |= GMAC_AN_CTRL_SGMRAL;
 
+	diff = old ^ value;
+	if (diff & ~GMAC_AN_CTRL_RAN) {
+		pr_warn("dwmac: PCS configuration changed from phylink by glue, please report: 0x%08x -> 0x%08x\n",
+			old & ~GMAC_AN_CTRL_RAN, value & ~GMAC_AN_CTRL_RAN);
+#define REPORT_BIT(x) \
+		if (diff & GMAC_AN_CTRL_##x) \
+			pr_warn("dwmac: %8s %u -> %u\n", #x, \
+				!!(old & GMAC_AN_CTRL_##x), \
+				!!(value & GMAC_AN_CTRL_##x))
+		REPORT_BIT(ANE);
+		REPORT_BIT(SGMRAL);
+#undef REPORT_BIT
+	}
+
 	writel(value, ioaddr + GMAC_AN_CTRL(reg));
 }
 #endif /* __STMMAC_PCS_H__ */
-- 
2.47.3

Re: [PATCH RFC net-next v2 0/7] net: stmmac: improve PCS support

[Mohd Ayaan Anwar]

Hi Russell,
On Wed, Mar 04, 2026 at 08:47:36AM +0000, Russell King (Oracle) wrote:
> Resending this as the original RFC now conflicts with net-next.
> 
> This series is the next of the three part series sorting out the PCS
> support in stmmac, building on part 2, which was posted yesterday:
> 
> 	net: stmmac: qcom-ethqos: further serdes reorganisation
> 
> Similar patches have been posted previously. This series does away with
> the common SerDes PHY support, instead using a flag to indicate whether
> 2500Mbps mode is supported (STMMAC_FLAG_SERDES_SUPPORTS_2500M.) At this
> time, I have no plans to resurect the common SerDes PHY support - the
> generic PHY layer implementations are just too random to consider that,
> and I certainly do not want the extra work of fixing that.
> 
> I've also changed the last patch which prints warnings when qcom-ethqos
> changes the PCS state - this will now indicate in a readable form
> whether the ANE or SGMRAL bits have changed state, rather than having
> to refer back to the definitions in the code or the databook.
> 
> I am hoping that - subject to this working for qcom-ethqos - we can
> drop this last patch in the final submission, along with the
> dwmac_ctrl_ane() and ethqos_pcs_set_inband() functions and associated
> definitions. This will also mean that stmmac will finally be driving
> the PCS correctly from a phylink point of view.
> 

Apologies for the delay in sharing test results. I had some board issues
to work through.

I applied your previous RFC series on top of the two qcom-ethqos/serdes
cleanup series and have the following results to report for the QCS9100
Ride R3 board (AQR115C PHY):

  - Link up at 2.5G, 1G, and 100M is fine (phylink logs below). The PCS
    link takes a moment to stabilize, but after that it's stable.
  - No data path issues at these speeds either.
  - The warning ("PCS configuration changed from phylink by glue;
    ANE 0 -> 1") is observed when the link comes up at 1G/100M.
  - I did find one issue: the data path breaks when the link speed
    changes from 2.5G to 1G or 100M. Notably, this is not consistently
    reproducible, and the issue persists even after *dropping* this
    series and the two qcom-ethqos/serdes cleanup series, so it appears
    to be pre-existing. I am trying to debug this separately.

    Two additional data points: this patch series may have increased the
    reproducibility rate to near-always, and the data path recovers
    after an administrative interface down/up cycle. Logs for both the
    working and non-working cases are included below.

  - Since I still have to test on IQ9 EVK (QCA8081 PHY), I am planning
    to rebase to the net-next tip and apply the latest version of the
    series. I will share an update in a couple of days.

    Ayaan

---
Logs

1. Boot up at 2.5G
	[   10.895909] qcom-ethqos 23040000.ethernet eth1: PHY stmmac-0:08 uses interfaces 4,23,27, validating 23
	[   10.905494] qcom-ethqos 23040000.ethernet eth1:  interface 23 (2500base-x) rate match pause supports 0-7,9,13-14,47
	[   10.905501] qcom-ethqos 23040000.ethernet eth1: PHY [stmmac-0:08] driver [Aquantia AQR115C] (irq=289)
	[   10.905504] qcom-ethqos 23040000.ethernet eth1: phy: 2500base-x setting supported 00000000,00000000,00008000,000062ff advertising 00000000,00000000,00008000,000062ff
	[   10.970145] qcom-ethqos 23040000.ethernet eth1: configuring for phy/2500base-x link mode
	[   10.978487] qcom-ethqos 23040000.ethernet eth1: major config, requested phy/2500base-x
	[   10.986630] qcom-ethqos 23040000.ethernet eth1: interface 2500base-x inband modes: pcs=01 phy=00
	[   10.986633] qcom-ethqos 23040000.ethernet eth1: major config, active phy/outband/2500base-x
	[   10.986636] qcom-ethqos 23040000.ethernet eth1: phylink_mac_config: mode=phy/2500base-x/none adv=00000000,00000000,00000000,00000000 pause=00
	[   10.999279] qcom-ethqos 23040000.ethernet eth1: phy link down 2500base-x/1Gbps/Full/none/off/nolpi
	[   11.524483] qcom-ethqos 23040000.ethernet eth1: Timeout accessing MAC_VLAN_Tag_Filter
	[   15.571728] qcom-ethqos 23040000.ethernet eth1: phy link up 2500base-x/2.5Gbps/Full/none/rx/tx/nolpi
	[   15.583871] qcom-ethqos 23040000.ethernet: PCS Link Up
	[   15.592285] qcom-ethqos 23040000.ethernet eth1: Link is Up - 2.5Gbps/Full - flow control rx/tx
	[   15.597500] qcom-ethqos 23040000.ethernet eth1: pcs link up

2. Boot up at 1G
	[   10.225496] qcom-ethqos 23040000.ethernet eth1: PHY stmmac-0:08 uses interfaces 4,23,27, validating 23
	[   10.225507] qcom-ethqos 23040000.ethernet eth1:  interface 23 (2500base-x) rate match pause supports 0-7,9,13-14,47
	[   10.225514] qcom-ethqos 23040000.ethernet eth1: PHY [stmmac-0:08] driver [Aquantia AQR115C] (irq=296)
	[   10.225518] qcom-ethqos 23040000.ethernet eth1: phy: 2500base-x setting supported 00000000,00000000,00008000,000062ff advertising 00000000,00000000,00008000,000062ff
	[   10.570643] qcom-ethqos 23040000.ethernet eth1: configuring for phy/2500base-x link mode
	[   10.578994] qcom-ethqos 23040000.ethernet eth1: major config, requested phy/2500base-x
	[   10.587126] qcom-ethqos 23040000.ethernet eth1: interface 2500base-x inband modes: pcs=01 phy=00
	[   10.596149] qcom-ethqos 23040000.ethernet eth1: major config, active phy/outband/2500base-x
	[   10.604727] qcom-ethqos 23040000.ethernet eth1: phylink_mac_config: mode=phy/2500base-x/none adv=00000000,00000000,00000000,00000000 pause=00
	[   10.635960] qcom-ethqos 23040000.ethernet eth1: phy link down 2500base-x/Unknown/Unknown/none/off/nolpi
	[   11.166068] qcom-ethqos 23040000.ethernet eth1: Timeout accessing MAC_VLAN_Tag_Filter
	[   14.009935] qcom-ethqos 23040000.ethernet eth1: phy link up sgmii/1Gbps/Full/none/rx/tx/nolpi
	[   14.021130] qcom-ethqos 23040000.ethernet eth1: major config, requested phy/sgmii
	[   14.028849] qcom-ethqos 23040000.ethernet eth1: interface sgmii inband modes: pcs=03 phy=03
	[   14.037455] qcom-ethqos 23040000.ethernet eth1: major config, active phy/outband/sgmii
	[   14.045597] qcom-ethqos 23040000.ethernet eth1: phylink_mac_config: mode=phy/sgmii/none adv=00000000,00000000,00000000,00000000 pause=03
	[   14.062429] dwmac: PCS configuration changed from phylink by glue, please report: 0x00040000 -> 0x00041000
	[   14.071296] qcom-ethqos 23040000.ethernet: PCS Link Up
	[   14.072349] dwmac:      ANE 0 -> 1
	[   14.077643] qcom-ethqos 23040000.ethernet eth1: pcs link up
	[   14.086899] qcom-ethqos 23040000.ethernet: PCS Link Down
	[   14.095640] qcom-ethqos 23040000.ethernet eth1: Link is Up - 1Gbps/Full - flow control rx/tx
	[   14.101012] qcom-ethqos 23040000.ethernet eth1: pcs link down
	[   14.104778] qcom-ethqos 23040000.ethernet: PCS ANE process completed
	[   14.109740] qcom-ethqos 23040000.ethernet eth1: Link is Down
	[   14.115609] qcom-ethqos 23040000.ethernet: PCS Link Up
	[   14.115616] qcom-ethqos 23040000.ethernet eth1: pcs link up
	[   14.143888] qcom-ethqos 23040000.ethernet: PCS ANE process completed
	[   14.147725] qcom-ethqos 23040000.ethernet eth1: Link is Up - 1Gbps/Full - flow control rx/tx
	[   14.154217] qcom-ethqos 23040000.ethernet: PCS Link Up
	[   14.154225] qcom-ethqos 23040000.ethernet eth1: pcs link up

3. Moving from 2.5G to 1G : non-working scenario
	[463994.745225] qcom-ethqos 23040000.ethernet eth1: pcs link up
	[463994.760504] qcom-ethqos 23040000.ethernet eth1: Link is Up - 2.5Gbps/Full - flow control rx/tx
						**DHCP/pings work fine**
						**Link speed changed to 1G**
	[464006.855060] qcom-ethqos 23040000.ethernet eth1: phy link down 2500base-x/2.5Gbps/Full/none/rx/tx/nolpi
	[464006.864767] qcom-ethqos 23040000.ethernet eth1: Link is Down
	[464010.370790] qcom-ethqos 23040000.ethernet eth1: phy link up sgmii/1Gbps/Full/none/rx/tx/nolpi
	[464010.377197] qcom-ethqos 23040000.ethernet: PCS Link Down
	[464010.382018] qcom-ethqos 23040000.ethernet eth1: major config, requested phy/sgmii
	[464010.385204] qcom-ethqos 23040000.ethernet eth1: pcs link down
	[464010.399011] qcom-ethqos 23040000.ethernet eth1: interface sgmii inband modes: pcs=03 phy=03
	[464010.407690] qcom-ethqos 23040000.ethernet eth1: major config, active phy/outband/sgmii
	[464010.415922] qcom-ethqos 23040000.ethernet eth1: phylink_mac_config: mode=phy/sgmii/none adv=00000000,00000000,00000000,00000000 pause=03
	[464010.440494] dwmac: PCS configuration changed from phylink by glue, please report: 0x00040000 -> 0x00041000
	[464010.440977] qcom-ethqos 23040000.ethernet: PCS Link Up
	[464010.450504] dwmac:      ANE 0 -> 1
	[464010.455870] qcom-ethqos 23040000.ethernet eth1: pcs link up
	[464010.465325] qcom-ethqos 23040000.ethernet eth1: Link is Up - 1Gbps/Full - flow control rx/tx
	[464010.465957] qcom-ethqos 23040000.ethernet: PCS Link Down
	[464010.474105] qcom-ethqos 23040000.ethernet eth1: Link is Down
	[464010.479633] qcom-ethqos 23040000.ethernet eth1: pcs link down
	[464010.500532] qcom-ethqos 23040000.ethernet eth1: Link is Up - 1Gbps/Full - flow control rx/tx

4. Moving from 2.5G to 1G : working scenario
						**Link speed changed to 1G**
	[  123.351212] qcom-ethqos 23040000.ethernet eth1: phy link down 2500base-x/2.5Gbps/Full/none/rxtx/nolpi
	[  123.360827] qcom-ethqos 23040000.ethernet eth1: Link is Down
	[  126.742306] qcom-ethqos 23040000.ethernet eth1: phy link up sgmii/1Gbps/Full/none/rx/tx/nolpi
	[  126.747557] qcom-ethqos 23040000.ethernet: PCS Link Down
	[  126.756547] qcom-ethqos 23040000.ethernet eth1: pcs link down
	[  126.762525] qcom-ethqos 23040000.ethernet eth1: major config, requested phy/sgmii
	[  126.770227] qcom-ethqos 23040000.ethernet eth1: interface sgmii inband modes: pcs=03 phy=03
	[  126.778814] qcom-ethqos 23040000.ethernet eth1: major config, active phy/outband/sgmii
	[  126.786958] qcom-ethqos 23040000.ethernet eth1: phylink_mac_config: mode=phy/sgmii/none adv=00000000,00000000,0000000,00000000 pause=03
	[  126.800656] qcom-ethqos 23040000.ethernet: PCS Link Up
	[  126.805951] qcom-ethqos 23040000.ethernet eth1: pcs link up
	[  126.812286] qcom-ethqos 23040000.ethernet: PCS Link Down
	[  126.817748] qcom-ethqos 23040000.ethernet eth1: pcs link down
	[  126.823693] qcom-ethqos 23040000.ethernet: PCS Link Up
	[  126.828973] qcom-ethqos 23040000.ethernet eth1: pcs link up
	[  126.837039] [DBG - SerDes update] ethqos_fix_mac_speed called with speed 1000, interface sgmii
	[  126.846539] dwmac: PCS configuration changed from phylink by glue, please report: 0x00040000 -> 0x00041000
	[  126.856546] dwmac:      ANE 0 -> 1
	[  126.860098] qcom-ethqos 23040000.ethernet eth1: Link is Up - 1Gbps/Full - flow control rx/tx
	[  126.860554] qcom-ethqos 23040000.ethernet: PCS Link Down
	[  126.868794] qcom-ethqos 23040000.ethernet eth1: Link is Down
	[  126.874228] qcom-ethqos 23040000.ethernet eth1: pcs link down
	[  126.874286] qcom-ethqos 23040000.ethernet: PCS ANE process completed
	[  126.880062] [DBG - SerDes update] ethqos_fix_mac_speed called with speed 1000, interface sgmii
	[  126.885958] qcom-ethqos 23040000.ethernet: PCS Link Up
	[  126.885966] qcom-ethqos 23040000.ethernet eth1: pcs link up
	[  126.892519] qcom-ethqos 23040000.ethernet eth1: Link is Up - 1Gbps/Full - flow control rx/tx
	[  126.901370] qcom-ethqos 23040000.ethernet: PCS ANE process completed
	[  126.927532] qcom-ethqos 23040000.ethernet: PCS Link Up
	[  126.932822] qcom-ethqos 23040000.ethernet eth1: pcs link up

Re: [PATCH RFC net-next v2 0/7] net: stmmac: improve PCS support

[Russell King (Oracle)]

On Fri, Mar 06, 2026 at 01:16:47AM +0530, Mohd Ayaan Anwar wrote:
> Hi Russell,
> On Wed, Mar 04, 2026 at 08:47:36AM +0000, Russell King (Oracle) wrote:
> > Resending this as the original RFC now conflicts with net-next.
> > 
> > This series is the next of the three part series sorting out the PCS
> > support in stmmac, building on part 2, which was posted yesterday:
> > 
> > 	net: stmmac: qcom-ethqos: further serdes reorganisation
> > 
> > Similar patches have been posted previously. This series does away with
> > the common SerDes PHY support, instead using a flag to indicate whether
> > 2500Mbps mode is supported (STMMAC_FLAG_SERDES_SUPPORTS_2500M.) At this
> > time, I have no plans to resurect the common SerDes PHY support - the
> > generic PHY layer implementations are just too random to consider that,
> > and I certainly do not want the extra work of fixing that.
> > 
> > I've also changed the last patch which prints warnings when qcom-ethqos
> > changes the PCS state - this will now indicate in a readable form
> > whether the ANE or SGMRAL bits have changed state, rather than having
> > to refer back to the definitions in the code or the databook.
> > 
> > I am hoping that - subject to this working for qcom-ethqos - we can
> > drop this last patch in the final submission, along with the
> > dwmac_ctrl_ane() and ethqos_pcs_set_inband() functions and associated
> > definitions. This will also mean that stmmac will finally be driving
> > the PCS correctly from a phylink point of view.
> > 
> 
> Apologies for the delay in sharing test results. I had some board issues
> to work through.
> 
> I applied your previous RFC series on top of the two qcom-ethqos/serdes
> cleanup series and have the following results to report for the QCS9100
> Ride R3 board (AQR115C PHY):
> 
>   - Link up at 2.5G, 1G, and 100M is fine (phylink logs below). The PCS
>     link takes a moment to stabilize, but after that it's stable.

Has it always taken a moment to stabilise? Note that the ANE changes
will trigger a re-exchange of SGMII in-band, which is why you see
the PCS link go down and back up after the "ANE 0->1" message.

I do notice:

	qcom-ethqos 23040000.ethernet eth1: Timeout accessing MAC_VLAN_Tag_Filter

which is a symptom that a clock is missing. There's been some recent
patches merged into net-next which changes this:

2cd70e3968f5 net: stmmac: Defer VLAN HW configuration when interface is down
bd7ad51253a7 net: stmmac: Fix VLAN HW state restore
e38200e361cb net: stmmac: Improve double VLAN handling
35dfedce442c net: stmmac: Fix error handling in VLAN add and delete paths

please indicate whether you have these applied.

>   - No data path issues at these speeds either.

Great.

>   - The warning ("PCS configuration changed from phylink by glue;
>     ANE 0 -> 1") is observed when the link comes up at 1G/100M.

That's currently expected, because phylink thinks we're using PHY
mode (where it's in charge of reading the PHY and telling the MAC
what's going on) rather than using inband. This is something that
will need to be addressed later.

>   - I did find one issue: the data path breaks when the link speed
>     changes from 2.5G to 1G or 100M. Notably, this is not consistently
>     reproducible, and the issue persists even after *dropping* this
>     series and the two qcom-ethqos/serdes cleanup series, so it appears
>     to be pre-existing. I am trying to debug this separately.

I think you added some debug between the logs that you've provided
below, which I'll take as not significant.

I think what's happening is the PHY's SGMII exchange times out, but
because you're enabling SGMII with AN at the PCS, the PCS is wanting
that to complete, and that never happens. I suspect if you unplug and
replug the cable after its switched into 1G mode, it may work. However,
I need to check whether AQR115C does this "AN bypass" thing.

That said, as we're using outband mode, phylink will call
phy_config_inband() with LINK_INBAND_DISABLE. This should disable
inband mode at the PHY, but from your logs I see evidence that it
hasn't. I think that may be because the AQR needs something more than
writing the VEND1_GLOBAL_CFG_* registers for that to take effect.

One of the hacks I have locally for an AQR113C on a SFP module which
uses 10GBASE-R with rate matching is the following in
aqr_gen4_config_init() to allow it to work with MACs that only support
up to 2.5G:

        phy_set_bits_mmd(phydev, MDIO_MMD_VEND1, MDIO_CTRL1, MDIO_CTRL1_LPOWER);
        mdelay(10);
        phy_write_mmd(phydev, MDIO_MMD_VEND1, 0x31a, 2);
        phy_write_mmd(phydev, MDIO_MMD_VEND1, VEND1_GLOBAL_CFG_10M,
                      VEND1_GLOBAL_CFG_AUTONEG_ENA |
                      VEND1_GLOBAL_CFG_SERDES_MODE_SGMII);
        phy_write_mmd(phydev, MDIO_MMD_VEND1, VEND1_GLOBAL_CFG_100M,
                      VEND1_GLOBAL_CFG_AUTONEG_ENA |
                      VEND1_GLOBAL_CFG_SERDES_MODE_SGMII);
        phy_write_mmd(phydev, MDIO_MMD_VEND1, VEND1_GLOBAL_CFG_1G,
                      VEND1_GLOBAL_CFG_AUTONEG_ENA |
                      VEND1_GLOBAL_CFG_SERDES_MODE_SGMII);
        phy_write_mmd(phydev, MDIO_MMD_VEND1, VEND1_GLOBAL_CFG_2_5G,
                      VEND1_GLOBAL_CFG_AUTONEG_ENA |
                      VEND1_GLOBAL_CFG_SERDES_MODE_OCSGMII);
        phy_clear_bits_mmd(phydev, MDIO_MMD_VEND1, MDIO_CTRL1,
                           MDIO_CTRL1_LPOWER);

I have this immediately after "priv->wait_on_global_cfg = true;"

This reprograms the vendor provisioning so that we use 2500BASE-X
for 2.5G and SGMII for 1G and below with AN enabled. Note placing
the PHY into low-power mode while doing this - this causes firmware
to re-read when exiting low-power mode. I wonder if that's required
in aqr_gen2_config_inband() - but that will cause the link to go
down.

Note that VEND1_GLOBAL_CFG_AUTONEG_ENA enables inband signalling on
the link.

With the above, you should be able to test various scenarios with
the PHY - and changing your provisioned 10M configuration will likely
get 10M speeds working.

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

Re: [PATCH RFC net-next v2 0/7] net: stmmac: improve PCS support

[Mohd Ayaan Anwar]

On Fri, Mar 06, 2026 at 09:47:57PM +0000, Russell King (Oracle) wrote:
> Has it always taken a moment to stabilise? Note that the ANE changes
> will trigger a re-exchange of SGMII in-band, which is why you see
> the PCS link go down and back up after the "ANE 0->1" message.
> 
> I do notice:
> 
> 	qcom-ethqos 23040000.ethernet eth1: Timeout accessing MAC_VLAN_Tag_Filter
> 
> which is a symptom that a clock is missing. There's been some recent
> patches merged into net-next which changes this:
> 
> 2cd70e3968f5 net: stmmac: Defer VLAN HW configuration when interface is down
> bd7ad51253a7 net: stmmac: Fix VLAN HW state restore
> e38200e361cb net: stmmac: Improve double VLAN handling
> 35dfedce442c net: stmmac: Fix error handling in VLAN add and delete paths
> 
> please indicate whether you have these applied.

I don't have these applied. I was running these tests with my tree which
had the serdes patches. I will move to net-next now since those are
merged.

I should have done a better job of cleaning up the logs, the VLAN filter
timeout has been there since forever.

> That's currently expected, because phylink thinks we're using PHY
> mode (where it's in charge of reading the PHY and telling the MAC
> what's going on) rather than using inband. This is something that
> will need to be addressed later.

Understood.

> I think you added some debug between the logs that you've provided
> below, which I'll take as not significant.

Yes, please ignore them. I forgot to clean them up.

> This reprograms the vendor provisioning so that we use 2500BASE-X
> for 2.5G and SGMII for 1G and below with AN enabled. Note placing
> the PHY into low-power mode while doing this - this causes firmware
> to re-read when exiting low-power mode. I wonder if that's required
> in aqr_gen2_config_inband() - but that will cause the link to go
> down.
> 
> Note that VEND1_GLOBAL_CFG_AUTONEG_ENA enables inband signalling on
> the link.
> 
> With the above, you should be able to test various scenarios with
> the PHY - and changing your provisioned 10M configuration will likely
> get 10M speeds working.

I will pick up v3 and try this out if needed.
I am also going to test these changes on IQ9 with the QCA8081 PHY which
shouldn't have this issue.

Thanks!

	Ayaan

Re: [PATCH RFC net-next v2 0/7] net: stmmac: improve PCS support

[Russell King (Oracle)]

On Mon, Mar 09, 2026 at 05:56:50PM +0530, Mohd Ayaan Anwar wrote:
> I will pick up v3 and try this out if needed.
> I am also going to test these changes on IQ9 with the QCA8081 PHY which
> shouldn't have this issue.

Oh, hmm. I suspect that we need to make the default_an_inband patch
conditional on !RGMII.

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

Re: [PATCH RFC net-next v2 0/7] net: stmmac: improve PCS support

[Russell King (Oracle)]

On Fri, Mar 06, 2026 at 01:16:47AM +0530, Mohd Ayaan Anwar wrote:
>   - Link up at 2.5G, 1G, and 100M is fine (phylink logs below). The PCS
>     link takes a moment to stabilize, but after that it's stable.
>   - The warning ("PCS configuration changed from phylink by glue;
>     ANE 0 -> 1") is observed when the link comes up at 1G/100M.

Something else to try...

It may avoid some PCS link state bouncing if the writel() came before
the printing of the changes in dwmac_ctrl_ane(), as printing those
changes will be relatively slow.

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Re: [PATCH RFC net-next v2 0/7] net: stmmac: improve PCS support

[Russell King (Oracle)]

On Wed, Mar 04, 2026 at 08:47:36AM +0000, Russell King (Oracle) wrote:
> Resending this as the original RFC now conflicts with net-next.
> 
> This series is the next of the three part series sorting out the PCS
> support in stmmac, building on part 2, which was posted yesterday:
> 
> 	net: stmmac: qcom-ethqos: further serdes reorganisation
> 
> Similar patches have been posted previously. This series does away with
> the common SerDes PHY support, instead using a flag to indicate whether
> 2500Mbps mode is supported (STMMAC_FLAG_SERDES_SUPPORTS_2500M.) At this
> time, I have no plans to resurect the common SerDes PHY support - the
> generic PHY layer implementations are just too random to consider that,
> and I certainly do not want the extra work of fixing that.

I'm intending to tweak this patch series slightly. First, reordering
the patches, moving patches 4 and 5 to the beginning of the series,
followed by patch 1, 3 and 2.

The first two add support for reading the SGMII status from hardware
which we don't currently use, then we add support for BASE-X and
start using it for 2500BASE-X for qcom-ethqos. This should result in
no change at this point.

Next, I'm intending to add a new patch which sets
plat_dat->mdio_bus_data->default_an_inband = true; which will enable
in-band mode, and thus start using the SGMII link state. This will
be used where the inband caps indicates both the PHY and PCS suport
inband. For 2500BASE-X, because the PCS reports a value of 0x01,
that will switch phylink automatically out of inband mode.

This should mean that phylink will switch to inband mode for SGMII,
and outband for 2500BASE-X, which will eliminate the PCS configuration
change done by qcom-ethqos.

I've also changed the "report PCS configuration changes" as I
suggested, although this should no longer trigger.

I'll post this shortly.

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