[PATCH net-next 0/8] net: dsa: microchip: Add PTP support for the KSZ8463

[PATCH net-next 0/8] net: dsa: microchip: Add PTP support for the KSZ8463

[Bastien Curutchet (Schneider Electric)]

Hi all,

This series aims to add two-step PTP support for the KSZ8463 driver. It
depends on a previous series that was recently applied to net-next:
https://lore.kernel.org/all/20260105-ksz-rework-v1-0-a68df7f57375@bootlin.com/

I've encountered weird behavior with IPv4 and IPv6 layers -- maybe that's
related to the incompatibility with the Linux stack mentionned by commit
620e2392db235 ("net: dsa: microchip: Disable PTP function of KSZ8463") ? --
So the support is only added for the L2 layer.

Patches 1 to 4 add IRQ support for the KSZ8463
Patch 5 adds specific dsa_device_ops for the KSZ8463
Patches 6 to 8 add PTP support for the KSZ8463

Signed-off-by: Bastien Curutchet (Schneider Electric) <bastien.curutchet@bootlin.com>
---
Bastien Curutchet (Schneider Electric) (8):
      net: dsa: microchip: Add support for KSZ8463 global irq
      net: dsa: microchip: Decorrelate IRQ domain from port
      net: dsa: microchip: Decorrelate msg_irq index from IRQ bit offset
      net: dsa: microchip: Add support for KSZ8463's PTP interrupts
      net: dsa: microchip: Add KSZ8463 tail tag handling
      net: dsa: microchip: Enable Ethernet PTP detection
      net: dsa: microchip: Adapt port offset for KSZ8463's PTP register
      net: dsa: microchip: Add two-step PTP support for KSZ8463

 drivers/net/dsa/microchip/ksz8.c        |  18 +---
 drivers/net/dsa/microchip/ksz8_reg.h    |   1 +
 drivers/net/dsa/microchip/ksz_common.c  |  95 ++++++++++++-----
 drivers/net/dsa/microchip/ksz_common.h  |   6 ++
 drivers/net/dsa/microchip/ksz_ptp.c     | 180 ++++++++++++++++++++++++++++----
 drivers/net/dsa/microchip/ksz_ptp.h     |   9 ++
 drivers/net/dsa/microchip/ksz_ptp_reg.h |  11 ++
 include/net/dsa.h                       |   2 +
 net/dsa/tag_ksz.c                       | 104 ++++++++++++++++++
 9 files changed, 369 insertions(+), 57 deletions(-)
---
base-commit: 3adff276e751051e77be4df8d29eab1cf0856fbf
change-id: 20260109-ksz8463-ptp-bc723ca7fac4

Best regards,
-- 
Bastien Curutchet (Schneider Electric) <bastien.curutchet@bootlin.com>

[PATCH net-next 1/8] net: dsa: microchip: Add support for KSZ8463 global irq

[Bastien Curutchet (Schneider Electric)]

KSZ8463's interrupt scheme differs from the others KSZ swicthes. Its
global interrupt handling is done through an 'enable irq' register
instead of a 'mask irq' one, so the bit logic to enable/disable
interrupt is reversed. Also its interrupts registers are 16-bits
registers and don't have the same address.

Add ksz8463-specific global interrupt setup function that still relies
on the ksz_irq_common_setup().
Add a check on the device type in the irq_chip operations to adjust the
bit logic for KSZ8463

Signed-off-by: Bastien Curutchet (Schneider Electric) <bastien.curutchet@bootlin.com>
---
 drivers/net/dsa/microchip/ksz_common.c | 40 +++++++++++++++++++++++++++++-----
 drivers/net/dsa/microchip/ksz_common.h |  3 +++
 2 files changed, 37 insertions(+), 6 deletions(-)

diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c
index e5fa1f5fc09b37c1a9d907175f8cd2cd60aee180..82ec7142a02c432f162e472c831faa010c035123 100644
--- a/drivers/net/dsa/microchip/ksz_common.c
+++ b/drivers/net/dsa/microchip/ksz_common.c
@@ -2817,14 +2817,20 @@ static void ksz_irq_mask(struct irq_data *d)
 {
 	struct ksz_irq *kirq = irq_data_get_irq_chip_data(d);
 
-	kirq->masked |= BIT(d->hwirq);
+	if (ksz_is_ksz8463(kirq->dev))
+		kirq->masked &= ~BIT(d->hwirq);
+	else
+		kirq->masked |= BIT(d->hwirq);
 }
 
 static void ksz_irq_unmask(struct irq_data *d)
 {
 	struct ksz_irq *kirq = irq_data_get_irq_chip_data(d);
 
-	kirq->masked &= ~BIT(d->hwirq);
+	if (ksz_is_ksz8463(kirq->dev))
+		kirq->masked |= BIT(d->hwirq);
+	else
+		kirq->masked &= ~BIT(d->hwirq);
 }
 
 static void ksz_irq_bus_lock(struct irq_data *d)
@@ -2840,7 +2846,10 @@ static void ksz_irq_bus_sync_unlock(struct irq_data *d)
 	struct ksz_device *dev = kirq->dev;
 	int ret;
 
-	ret = ksz_write8(dev, kirq->reg_mask, kirq->masked);
+	if (ksz_is_ksz8463(dev))
+		ret = ksz_write16(dev, kirq->reg_mask, kirq->masked);
+	else
+		ret = ksz_write8(dev, kirq->reg_mask, kirq->masked);
 	if (ret)
 		dev_err(dev->dev, "failed to change IRQ mask\n");
 
@@ -2890,14 +2899,14 @@ static irqreturn_t ksz_irq_thread_fn(int irq, void *dev_id)
 	unsigned int nhandled = 0;
 	struct ksz_device *dev;
 	unsigned int sub_irq;
-	u8 data;
+	u16 data;
 	int ret;
 	u8 n;
 
 	dev = kirq->dev;
 
 	/* Read interrupt status register */
-	ret = ksz_read8(dev, kirq->reg_status, &data);
+	ret = ksz_read16(dev, kirq->reg_status, &data);
 	if (ret)
 		goto out;
 
@@ -2939,6 +2948,22 @@ static int ksz_irq_common_setup(struct ksz_device *dev, struct ksz_irq *kirq)
 	return ret;
 }
 
+static int ksz8463_girq_setup(struct dsa_switch *ds)
+{
+	struct ksz_device *dev = ds->priv;
+	struct ksz_irq *girq = &dev->girq;
+
+	girq->nirqs = 15;
+	girq->reg_mask = KSZ8463_REG_IER;
+	girq->reg_status = KSZ8463_REG_ISR;
+	girq->masked = 0;
+	snprintf(girq->name, sizeof(girq->name), "global_irq");
+
+	girq->irq_num = dev->irq;
+
+	return ksz_irq_common_setup(dev, girq);
+}
+
 static int ksz_girq_setup(struct ksz_device *dev)
 {
 	struct ksz_irq *girq = &dev->girq;
@@ -3044,7 +3069,10 @@ static int ksz_setup(struct dsa_switch *ds)
 	p->learning = true;
 
 	if (dev->irq > 0) {
-		ret = ksz_girq_setup(dev);
+		if (ksz_is_ksz8463(dev))
+			ret = ksz8463_girq_setup(ds);
+		else
+			ret = ksz_girq_setup(dev);
 		if (ret)
 			return ret;
 
diff --git a/drivers/net/dsa/microchip/ksz_common.h b/drivers/net/dsa/microchip/ksz_common.h
index 929aff4c55de5254defdc1afb52b224b3898233b..67a488a3b5787f93f9e2a9266ce04f6611b56bf8 100644
--- a/drivers/net/dsa/microchip/ksz_common.h
+++ b/drivers/net/dsa/microchip/ksz_common.h
@@ -839,6 +839,9 @@ static inline bool ksz_is_sgmii_port(struct ksz_device *dev, int port)
 #define KSZ87XX_INT_PME_MASK		BIT(4)
 
 /* Interrupt */
+#define KSZ8463_REG_ISR			0x190
+#define KSZ8463_REG_IER			0x192
+
 #define REG_SW_PORT_INT_STATUS__1	0x001B
 #define REG_SW_PORT_INT_MASK__1		0x001F
 

-- 
2.52.0

[PATCH net-next 2/8] net: dsa: microchip: Decorrelate IRQ domain from port

[Bastien Curutchet (Schneider Electric)]

KSZ8463 has one register holding interrupt bits from both port 1 and 2.
So it has to use one IRQ domain for both of its ports. This conflicts
with the current initialization procedure that ties one IRQ domain to
each port.

Decorrelate IRQ domain from port so a port can use an IRQ domain not
directly related to itself.

Signed-off-by: Bastien Curutchet (Schneider Electric) <bastien.curutchet@bootlin.com>
---
 drivers/net/dsa/microchip/ksz_ptp.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/net/dsa/microchip/ksz_ptp.c b/drivers/net/dsa/microchip/ksz_ptp.c
index 4a2cc57a628f97bd51fcb11057bc4effda9205dd..3b0dddf918595e9318c9e9779035d5152dcd9dde 100644
--- a/drivers/net/dsa/microchip/ksz_ptp.c
+++ b/drivers/net/dsa/microchip/ksz_ptp.c
@@ -1099,18 +1099,17 @@ static void ksz_ptp_msg_irq_free(struct ksz_port *port, u8 n)
 	irq_dispose_mapping(ptpmsg_irq->num);
 }
 
-static int ksz_ptp_msg_irq_setup(struct ksz_port *port, u8 n)
+static int ksz_ptp_msg_irq_setup(struct irq_domain *domain, struct ksz_port *port, u8 n)
 {
 	u16 ts_reg[] = {REG_PTP_PORT_PDRESP_TS, REG_PTP_PORT_XDELAY_TS,
 			REG_PTP_PORT_SYNC_TS};
 	static const char * const name[] = {"pdresp-msg", "xdreq-msg",
 					    "sync-msg"};
 	const struct ksz_dev_ops *ops = port->ksz_dev->dev_ops;
-	struct ksz_irq *ptpirq = &port->ptpirq;
 	struct ksz_ptp_irq *ptpmsg_irq;
 
 	ptpmsg_irq = &port->ptpmsg_irq[n];
-	ptpmsg_irq->num = irq_create_mapping(ptpirq->domain, n);
+	ptpmsg_irq->num = irq_create_mapping(domain, n);
 	if (!ptpmsg_irq->num)
 		return -EINVAL;
 
@@ -1162,7 +1161,7 @@ int ksz_ptp_irq_setup(struct dsa_switch *ds, u8 p)
 		goto out;
 
 	for (irq = 0; irq < ptpirq->nirqs; irq++) {
-		ret = ksz_ptp_msg_irq_setup(port, irq);
+		ret = ksz_ptp_msg_irq_setup(ptpirq->domain, port, irq);
 		if (ret)
 			goto out_ptp_msg;
 	}

-- 
2.52.0

[PATCH net-next 3/8] net: dsa: microchip: Decorrelate msg_irq index from IRQ bit offset

[Bastien Curutchet (Schneider Electric)]

KSZ8463 has one register containing all the PTP-related interrupts from
all ports. So it will use one IRQ domain for all of them, leading to 4
interrupt bits to be dispatched in two ports. Current implementation
doesn't allow to do so because the IRQ bit offset is also used as index
to store the struct ptpmsg_irq in the table held by the port.

Add a new input to the setup() function to independently provide the
interrupt bit offset and the ptpmsg_irq index.

Signed-off-by: Bastien Curutchet (Schneider Electric) <bastien.curutchet@bootlin.com>
---
 drivers/net/dsa/microchip/ksz_ptp.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/net/dsa/microchip/ksz_ptp.c b/drivers/net/dsa/microchip/ksz_ptp.c
index 3b0dddf918595e9318c9e9779035d5152dcd9dde..ae46ba41c588c076de2c3b70c7c6702ad85263d5 100644
--- a/drivers/net/dsa/microchip/ksz_ptp.c
+++ b/drivers/net/dsa/microchip/ksz_ptp.c
@@ -1099,7 +1099,8 @@ static void ksz_ptp_msg_irq_free(struct ksz_port *port, u8 n)
 	irq_dispose_mapping(ptpmsg_irq->num);
 }
 
-static int ksz_ptp_msg_irq_setup(struct irq_domain *domain, struct ksz_port *port, u8 n)
+static int ksz_ptp_msg_irq_setup(struct irq_domain *domain, struct ksz_port *port,
+				 u8 index, int irq)
 {
 	u16 ts_reg[] = {REG_PTP_PORT_PDRESP_TS, REG_PTP_PORT_XDELAY_TS,
 			REG_PTP_PORT_SYNC_TS};
@@ -1108,15 +1109,15 @@ static int ksz_ptp_msg_irq_setup(struct irq_domain *domain, struct ksz_port *por
 	const struct ksz_dev_ops *ops = port->ksz_dev->dev_ops;
 	struct ksz_ptp_irq *ptpmsg_irq;
 
-	ptpmsg_irq = &port->ptpmsg_irq[n];
-	ptpmsg_irq->num = irq_create_mapping(domain, n);
+	ptpmsg_irq = &port->ptpmsg_irq[index];
+	ptpmsg_irq->num = irq_create_mapping(domain, irq);
 	if (!ptpmsg_irq->num)
 		return -EINVAL;
 
 	ptpmsg_irq->port = port;
-	ptpmsg_irq->ts_reg = ops->get_port_addr(port->num, ts_reg[n]);
+	ptpmsg_irq->ts_reg = ops->get_port_addr(port->num, ts_reg[index]);
 
-	strscpy(ptpmsg_irq->name, name[n]);
+	strscpy(ptpmsg_irq->name, name[index]);
 
 	return request_threaded_irq(ptpmsg_irq->num, NULL,
 				    ksz_ptp_msg_thread_fn, IRQF_ONESHOT,
@@ -1161,7 +1162,7 @@ int ksz_ptp_irq_setup(struct dsa_switch *ds, u8 p)
 		goto out;
 
 	for (irq = 0; irq < ptpirq->nirqs; irq++) {
-		ret = ksz_ptp_msg_irq_setup(ptpirq->domain, port, irq);
+		ret = ksz_ptp_msg_irq_setup(ptpirq->domain, port, irq, irq);
 		if (ret)
 			goto out_ptp_msg;
 	}

-- 
2.52.0

[PATCH net-next 4/8] net: dsa: microchip: Add support for KSZ8463's PTP interrupts

[Bastien Curutchet (Schneider Electric)]

KSZ8463 PTP interrupts aren't handled by the driver.
The interrupt layout in KSZ8463 has nothing to do with the other
switches:
- all the interrupts of all ports are grouped into one status register
  while others have one interrupt register per port
- xdelay_req and pdresp timestamps share one single interrupt bit on the
  KSZ8463 while each of them has its own interrupt bit on other switches

Add KSZ8463-specific IRQ setup()/free() functions to support KSZ8463.
Both ports share one IRQ domain held by port n°1.

Signed-off-by: Bastien Curutchet (Schneider Electric) <bastien.curutchet@bootlin.com>
---
 drivers/net/dsa/microchip/ksz_common.c  |  49 +++++++++-----
 drivers/net/dsa/microchip/ksz_common.h  |   2 +
 drivers/net/dsa/microchip/ksz_ptp.c     | 114 +++++++++++++++++++++++++++++++-
 drivers/net/dsa/microchip/ksz_ptp.h     |   9 +++
 drivers/net/dsa/microchip/ksz_ptp_reg.h |   7 ++
 5 files changed, 162 insertions(+), 19 deletions(-)

diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c
index 82ec7142a02c432f162e472c831faa010c035123..224be307b3417bf30d62da5c94efc6714d914dc6 100644
--- a/drivers/net/dsa/microchip/ksz_common.c
+++ b/drivers/net/dsa/microchip/ksz_common.c
@@ -3076,15 +3076,21 @@ static int ksz_setup(struct dsa_switch *ds)
 		if (ret)
 			return ret;
 
-		dsa_switch_for_each_user_port(dp, dev->ds) {
-			ret = ksz_pirq_setup(dev, dp->index);
+		if (ksz_is_ksz8463(dev)) {
+			ret = ksz8463_ptp_irq_setup(ds);
 			if (ret)
-				goto port_release;
-
-			if (dev->info->ptp_capable) {
-				ret = ksz_ptp_irq_setup(ds, dp->index);
+				goto girq_release;
+		} else {
+			dsa_switch_for_each_user_port(dp, dev->ds) {
+				ret = ksz_pirq_setup(dev, dp->index);
 				if (ret)
-					goto pirq_release;
+					goto port_release;
+
+				if (dev->info->ptp_capable) {
+					ret = ksz_ptp_irq_setup(ds, dp->index);
+					if (ret)
+						goto pirq_release;
+				}
 			}
 		}
 	}
@@ -3119,14 +3125,20 @@ static int ksz_setup(struct dsa_switch *ds)
 		ksz_ptp_clock_unregister(ds);
 port_release:
 	if (dev->irq > 0) {
-		dsa_switch_for_each_user_port_continue_reverse(dp, dev->ds) {
-			if (dev->info->ptp_capable)
-				ksz_ptp_irq_free(ds, dp->index);
+		if (ksz_is_ksz8463(dev)) {
+			ksz8463_ptp_irq_free(ds);
+		} else {
+			dsa_switch_for_each_user_port_continue_reverse(dp, dev->ds) {
+				if (dev->info->ptp_capable)
+					ksz_ptp_irq_free(ds, dp->index);
 pirq_release:
-			ksz_irq_free(&dev->ports[dp->index].pirq);
+				ksz_irq_free(&dev->ports[dp->index].pirq);
+			}
 		}
-		ksz_irq_free(&dev->girq);
 	}
+girq_release:
+	if (dev->irq > 0)
+		ksz_irq_free(&dev->girq);
 
 	return ret;
 }
@@ -3140,11 +3152,14 @@ static void ksz_teardown(struct dsa_switch *ds)
 		ksz_ptp_clock_unregister(ds);
 
 	if (dev->irq > 0) {
-		dsa_switch_for_each_user_port(dp, dev->ds) {
-			if (dev->info->ptp_capable)
-				ksz_ptp_irq_free(ds, dp->index);
-
-			ksz_irq_free(&dev->ports[dp->index].pirq);
+		if (ksz_is_ksz8463(dev)) {
+			ksz8463_ptp_irq_free(ds);
+		} else {
+			dsa_switch_for_each_user_port(dp, dev->ds) {
+				if (dev->info->ptp_capable)
+					ksz_ptp_irq_free(ds, dp->index);
+				ksz_irq_free(&dev->ports[dp->index].pirq);
+			}
 		}
 
 		ksz_irq_free(&dev->girq);
diff --git a/drivers/net/dsa/microchip/ksz_common.h b/drivers/net/dsa/microchip/ksz_common.h
index 67a488a3b5787f93f9e2a9266ce04f6611b56bf8..dfbc3d13daca8d7a8b9d3ffe6a7c1ec9927863f2 100644
--- a/drivers/net/dsa/microchip/ksz_common.h
+++ b/drivers/net/dsa/microchip/ksz_common.h
@@ -851,6 +851,8 @@ static inline bool ksz_is_sgmii_port(struct ksz_device *dev, int port)
 #define PORT_SRC_PHY_INT		1
 #define PORT_SRC_PTP_INT		2
 
+#define KSZ8463_SRC_PTP_INT		12
+
 #define KSZ8795_HUGE_PACKET_SIZE	2000
 #define KSZ8863_HUGE_PACKET_SIZE	1916
 #define KSZ8863_NORMAL_PACKET_SIZE	1536
diff --git a/drivers/net/dsa/microchip/ksz_ptp.c b/drivers/net/dsa/microchip/ksz_ptp.c
index ae46ba41c588c076de2c3b70c7c6702ad85263d5..cafb64785ef4c7eb9c05900a87148e8b7b4678e5 100644
--- a/drivers/net/dsa/microchip/ksz_ptp.c
+++ b/drivers/net/dsa/microchip/ksz_ptp.c
@@ -31,6 +31,9 @@
 #define KSZ_PTP_SUBNS_BITS 32
 
 #define KSZ_PTP_INT_START 13
+#define KSZ8463_PTP_PORT1_INT_START 12
+#define KSZ8463_PTP_PORT2_INT_START 14
+#define KSZ8463_PTP_INT_START KSZ8463_PTP_PORT1_INT_START
 
 static int ksz_ptp_tou_gpio(struct ksz_device *dev)
 {
@@ -1102,6 +1105,7 @@ static void ksz_ptp_msg_irq_free(struct ksz_port *port, u8 n)
 static int ksz_ptp_msg_irq_setup(struct irq_domain *domain, struct ksz_port *port,
 				 u8 index, int irq)
 {
+	static const char * const ksz8463_name[] = {"sync-msg", "delay-msg"};
 	u16 ts_reg[] = {REG_PTP_PORT_PDRESP_TS, REG_PTP_PORT_XDELAY_TS,
 			REG_PTP_PORT_SYNC_TS};
 	static const char * const name[] = {"pdresp-msg", "xdreq-msg",
@@ -1115,15 +1119,108 @@ static int ksz_ptp_msg_irq_setup(struct irq_domain *domain, struct ksz_port *por
 		return -EINVAL;
 
 	ptpmsg_irq->port = port;
-	ptpmsg_irq->ts_reg = ops->get_port_addr(port->num, ts_reg[index]);
 
-	strscpy(ptpmsg_irq->name, name[index]);
+	if (ksz_is_ksz8463(port->ksz_dev)) {
+		ts_reg[0] = KSZ8463_REG_PORT_SYNC_TS;
+		ts_reg[1] = KSZ8463_REG_PORT_DREQ_TS;
+		strscpy(ptpmsg_irq->name, ksz8463_name[index]);
+	} else {
+		strscpy(ptpmsg_irq->name, name[index]);
+	}
+
+	ptpmsg_irq->ts_reg = ops->get_port_addr(port->num, ts_reg[index]);
 
 	return request_threaded_irq(ptpmsg_irq->num, NULL,
 				    ksz_ptp_msg_thread_fn, IRQF_ONESHOT,
 				    ptpmsg_irq->name, ptpmsg_irq);
 }
 
+static int ksz8463_ptp_port_irq_setup(struct ksz_irq *ptpirq, struct ksz_port *port, int hw_irq)
+{
+	int ret;
+	int i;
+
+	init_completion(&port->tstamp_msg_comp);
+
+	for (i = 0; i < 2; i++) {
+		ret = ksz_ptp_msg_irq_setup(ptpirq->domain, port, i, hw_irq++);
+		if (ret)
+			goto release_msg_irq;
+	}
+
+	return 0;
+
+release_msg_irq:
+	while (i--)
+		ksz_ptp_msg_irq_free(port, i);
+
+	return ret;
+}
+
+static void ksz8463_ptp_port_irq_teardown(struct ksz_port *port)
+{
+	int i;
+
+	for (i = 0; i < 2; i++)
+		ksz_ptp_msg_irq_free(port, i);
+}
+
+int ksz8463_ptp_irq_setup(struct dsa_switch *ds)
+{
+	struct ksz_device *dev = ds->priv;
+	const struct ksz_dev_ops *ops = dev->dev_ops;
+	struct ksz_port *port1, *port2;
+	struct ksz_irq *ptpirq;
+	int ret;
+	int p;
+
+	port1 = &dev->ports[0];
+	port2 = &dev->ports[1];
+	ptpirq = &port1->ptpirq;
+
+	ptpirq->irq_num = irq_find_mapping(dev->girq.domain, KSZ8463_SRC_PTP_INT);
+	if (!ptpirq->irq_num)
+		return -EINVAL;
+
+	ptpirq->dev = dev;
+	ptpirq->nirqs = 4;
+	ptpirq->reg_mask = ops->get_port_addr(p, KSZ8463_PTP_TS_IER);
+	ptpirq->reg_status = ops->get_port_addr(p, KSZ8463_PTP_TS_ISR);
+	ptpirq->irq0_offset = KSZ8463_PTP_INT_START;
+	snprintf(ptpirq->name, sizeof(ptpirq->name), "ptp-irq-%d", p);
+
+	ptpirq->domain = irq_domain_create_linear(dev_fwnode(dev->dev), ptpirq->nirqs,
+						  &ksz_ptp_irq_domain_ops, ptpirq);
+	if (!ptpirq->domain)
+		return -ENOMEM;
+
+	ret = request_threaded_irq(ptpirq->irq_num, NULL, ksz_ptp_irq_thread_fn,
+				   IRQF_ONESHOT, ptpirq->name, ptpirq);
+	if (ret)
+		goto release_domain;
+
+	ret = ksz8463_ptp_port_irq_setup(ptpirq, port1,
+					 KSZ8463_PTP_PORT1_INT_START - KSZ8463_PTP_INT_START);
+	if (ret)
+		goto release_irq;
+
+	ret = ksz8463_ptp_port_irq_setup(ptpirq, port2,
+					 KSZ8463_PTP_PORT2_INT_START - KSZ8463_PTP_INT_START);
+	if (ret)
+		goto free_port1;
+
+	return 0;
+
+free_port1:
+	ksz8463_ptp_port_irq_teardown(port1);
+release_irq:
+	free_irq(ptpirq->irq_num, ptpirq);
+release_domain:
+	irq_domain_remove(ptpirq->domain);
+
+	return ret;
+}
+
 int ksz_ptp_irq_setup(struct dsa_switch *ds, u8 p)
 {
 	struct ksz_device *dev = ds->priv;
@@ -1181,6 +1278,19 @@ int ksz_ptp_irq_setup(struct dsa_switch *ds, u8 p)
 	return ret;
 }
 
+void ksz8463_ptp_irq_free(struct dsa_switch *ds)
+{
+	struct ksz_device *dev = ds->priv;
+	struct ksz_port *port1 = &dev->ports[0];
+	struct ksz_port *port2 = &dev->ports[1];
+	struct ksz_irq *ptpirq = &port1->ptpirq;
+
+	ksz8463_ptp_port_irq_teardown(port1);
+	ksz8463_ptp_port_irq_teardown(port2);
+	free_irq(ptpirq->irq_num, ptpirq);
+	irq_domain_remove(ptpirq->domain);
+}
+
 void ksz_ptp_irq_free(struct dsa_switch *ds, u8 p)
 {
 	struct ksz_device *dev = ds->priv;
diff --git a/drivers/net/dsa/microchip/ksz_ptp.h b/drivers/net/dsa/microchip/ksz_ptp.h
index 3086e519b1b641e9e4126cb6ff43409f6d7f29a5..46494caacc4287b845b8e5c3a68bcfc7a03bcf9d 100644
--- a/drivers/net/dsa/microchip/ksz_ptp.h
+++ b/drivers/net/dsa/microchip/ksz_ptp.h
@@ -48,6 +48,8 @@ void ksz_port_txtstamp(struct dsa_switch *ds, int port, struct sk_buff *skb);
 void ksz_port_deferred_xmit(struct kthread_work *work);
 bool ksz_port_rxtstamp(struct dsa_switch *ds, int port, struct sk_buff *skb,
 		       unsigned int type);
+int ksz8463_ptp_irq_setup(struct dsa_switch *ds);
+void ksz8463_ptp_irq_free(struct dsa_switch *ds);
 int ksz_ptp_irq_setup(struct dsa_switch *ds, u8 p);
 void ksz_ptp_irq_free(struct dsa_switch *ds, u8 p);
 
@@ -65,6 +67,13 @@ static inline int ksz_ptp_clock_register(struct dsa_switch *ds)
 
 static inline void ksz_ptp_clock_unregister(struct dsa_switch *ds) { }
 
+static inline int ksz8463_ptp_irq_setup(struct dsa_switch *ds)
+{
+	return 0;
+}
+
+static inline void ksz8463_ptp_irq_free(struct dsa_switch *ds) {}
+
 static inline int ksz_ptp_irq_setup(struct dsa_switch *ds, u8 p)
 {
 	return 0;
diff --git a/drivers/net/dsa/microchip/ksz_ptp_reg.h b/drivers/net/dsa/microchip/ksz_ptp_reg.h
index eab9aecb7fa8a50323de4140695b2004d1beab8c..e80fb4bd1a0e970ba3570374d3dc82c8e2cc15b4 100644
--- a/drivers/net/dsa/microchip/ksz_ptp_reg.h
+++ b/drivers/net/dsa/microchip/ksz_ptp_reg.h
@@ -121,6 +121,10 @@
 #define REG_PTP_PORT_SYNC_TS		0x0C0C
 #define REG_PTP_PORT_PDRESP_TS		0x0C10
 
+#define KSZ8463_REG_PORT_DREQ_TS	0x0648
+#define KSZ8463_REG_PORT_SYNC_TS	0x064C
+#define KSZ8463_REG_PORT_DRESP_TS	0x0650
+
 #define REG_PTP_PORT_TX_INT_STATUS__2	0x0C14
 #define REG_PTP_PORT_TX_INT_ENABLE__2	0x0C16
 
@@ -131,4 +135,7 @@
 #define KSZ_XDREQ_MSG			1
 #define KSZ_PDRES_MSG			0
 
+#define KSZ8463_PTP_TS_ISR		0x68C
+#define KSZ8463_PTP_TS_IER		0x68E
+
 #endif

-- 
2.52.0

Re: [PATCH net-next 4/8] net: dsa: microchip: Add support for KSZ8463's PTP interrupts

[kernel test robot]

Hi Bastien,

kernel test robot noticed the following build warnings:

[auto build test WARNING on 3adff276e751051e77be4df8d29eab1cf0856fbf]

url:    https://github.com/intel-lab-lkp/linux/commits/Bastien-Curutchet-Schneider-Electric/net-dsa-microchip-Add-support-for-KSZ8463-global-irq/20260116-000545
base:   3adff276e751051e77be4df8d29eab1cf0856fbf
patch link:    https://lore.kernel.org/r/20260115-ksz8463-ptp-v1-4-bcfe2830cf50%40bootlin.com
patch subject: [PATCH net-next 4/8] net: dsa: microchip: Add support for KSZ8463's PTP interrupts
config: loongarch-allmodconfig (https://download.01.org/0day-ci/archive/20260116/202601160729.AzeG6b64-lkp@intel.com/config)
compiler: clang version 19.1.7 (https://github.com/llvm/llvm-project cd708029e0b2869e80abe31ddb175f7c35361f90)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260116/202601160729.AzeG6b64-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202601160729.AzeG6b64-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/net/dsa/microchip/ksz_ptp.c:1187:40: warning: variable 'p' is uninitialized when used here [-Wuninitialized]
    1187 |         ptpirq->reg_mask = ops->get_port_addr(p, KSZ8463_PTP_TS_IER);
         |                                               ^
   drivers/net/dsa/microchip/ksz_ptp.c:1175:7: note: initialize the variable 'p' to silence this warning
    1175 |         int p;
         |              ^
         |               = 0
   1 warning generated.


vim +/p +1187 drivers/net/dsa/microchip/ksz_ptp.c

  1167	
  1168	int ksz8463_ptp_irq_setup(struct dsa_switch *ds)
  1169	{
  1170		struct ksz_device *dev = ds->priv;
  1171		const struct ksz_dev_ops *ops = dev->dev_ops;
  1172		struct ksz_port *port1, *port2;
  1173		struct ksz_irq *ptpirq;
  1174		int ret;
  1175		int p;
  1176	
  1177		port1 = &dev->ports[0];
  1178		port2 = &dev->ports[1];
  1179		ptpirq = &port1->ptpirq;
  1180	
  1181		ptpirq->irq_num = irq_find_mapping(dev->girq.domain, KSZ8463_SRC_PTP_INT);
  1182		if (!ptpirq->irq_num)
  1183			return -EINVAL;
  1184	
  1185		ptpirq->dev = dev;
  1186		ptpirq->nirqs = 4;
> 1187		ptpirq->reg_mask = ops->get_port_addr(p, KSZ8463_PTP_TS_IER);
  1188		ptpirq->reg_status = ops->get_port_addr(p, KSZ8463_PTP_TS_ISR);
  1189		ptpirq->irq0_offset = KSZ8463_PTP_INT_START;
  1190		snprintf(ptpirq->name, sizeof(ptpirq->name), "ptp-irq-%d", p);
  1191	
  1192		ptpirq->domain = irq_domain_create_linear(dev_fwnode(dev->dev), ptpirq->nirqs,
  1193							  &ksz_ptp_irq_domain_ops, ptpirq);
  1194		if (!ptpirq->domain)
  1195			return -ENOMEM;
  1196	
  1197		ret = request_threaded_irq(ptpirq->irq_num, NULL, ksz_ptp_irq_thread_fn,
  1198					   IRQF_ONESHOT, ptpirq->name, ptpirq);
  1199		if (ret)
  1200			goto release_domain;
  1201	
  1202		ret = ksz8463_ptp_port_irq_setup(ptpirq, port1,
  1203						 KSZ8463_PTP_PORT1_INT_START - KSZ8463_PTP_INT_START);
  1204		if (ret)
  1205			goto release_irq;
  1206	
  1207		ret = ksz8463_ptp_port_irq_setup(ptpirq, port2,
  1208						 KSZ8463_PTP_PORT2_INT_START - KSZ8463_PTP_INT_START);
  1209		if (ret)
  1210			goto free_port1;
  1211	
  1212		return 0;
  1213	
  1214	free_port1:
  1215		ksz8463_ptp_port_irq_teardown(port1);
  1216	release_irq:
  1217		free_irq(ptpirq->irq_num, ptpirq);
  1218	release_domain:
  1219		irq_domain_remove(ptpirq->domain);
  1220	
  1221		return ret;
  1222	}
  1223	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

[PATCH net-next 5/8] net: dsa: microchip: Add KSZ8463 tail tag handling

[Bastien Curutchet (Schneider Electric)]

KSZ8463 uses the KSZ9893 DSA TAG driver. However, the KSZ8463 doesn't
use the tail tag to convey timestamps to the host as KSZ9893 does. It
uses the reserved fields in the PTP header instead.

Add a KSZ8463-specifig DSA_TAG driver to handle KSZ8463 timestamps.
There is no information in the tail tag to distinguish PTP packets from
others so use the ptp_classify_raw() helper to find the PTP packets and
extract the timestamp from their PTP headers.

Signed-off-by: Bastien Curutchet (Schneider Electric) <bastien.curutchet@bootlin.com>
---
 drivers/net/dsa/microchip/ksz_common.c |   5 +-
 include/net/dsa.h                      |   2 +
 net/dsa/tag_ksz.c                      | 104 +++++++++++++++++++++++++++++++++
 3 files changed, 110 insertions(+), 1 deletion(-)

diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c
index 224be307b3417bf30d62da5c94efc6714d914dc6..5141343d2f40bbd380c0b52f6919b842fb71a8fd 100644
--- a/drivers/net/dsa/microchip/ksz_common.c
+++ b/drivers/net/dsa/microchip/ksz_common.c
@@ -3580,8 +3580,10 @@ static enum dsa_tag_protocol ksz_get_tag_protocol(struct dsa_switch *ds,
 	if (ksz_is_ksz87xx(dev) || ksz_is_8895_family(dev))
 		proto = DSA_TAG_PROTO_KSZ8795;
 
+	if (dev->chip_id == KSZ8463_CHIP_ID)
+		proto = DSA_TAG_PROTO_KSZ8463;
+
 	if (dev->chip_id == KSZ88X3_CHIP_ID ||
-	    dev->chip_id == KSZ8463_CHIP_ID ||
 	    dev->chip_id == KSZ8563_CHIP_ID ||
 	    dev->chip_id == KSZ9893_CHIP_ID ||
 	    dev->chip_id == KSZ9563_CHIP_ID)
@@ -3611,6 +3613,7 @@ static int ksz_connect_tag_protocol(struct dsa_switch *ds,
 		return 0;
 	case DSA_TAG_PROTO_KSZ9893:
 	case DSA_TAG_PROTO_KSZ9477:
+	case DSA_TAG_PROTO_KSZ8463:
 	case DSA_TAG_PROTO_LAN937X:
 		tagger_data = ksz_tagger_data(ds);
 		tagger_data->xmit_work_fn = ksz_port_deferred_xmit;
diff --git a/include/net/dsa.h b/include/net/dsa.h
index 6b2b5ed64ea4cee6ab59c9e6eaab30f07f82816a..5b5fed6e6f9171f5875d61c1395758065ac5808a 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -57,6 +57,7 @@ struct tc_action;
 #define DSA_TAG_PROTO_BRCM_LEGACY_FCS_VALUE	29
 #define DSA_TAG_PROTO_YT921X_VALUE		30
 #define DSA_TAG_PROTO_MXL_GSW1XX_VALUE		31
+#define DSA_TAG_PROTO_KSZ8463_VALUE		32
 
 enum dsa_tag_protocol {
 	DSA_TAG_PROTO_NONE		= DSA_TAG_PROTO_NONE_VALUE,
@@ -91,6 +92,7 @@ enum dsa_tag_protocol {
 	DSA_TAG_PROTO_VSC73XX_8021Q	= DSA_TAG_PROTO_VSC73XX_8021Q_VALUE,
 	DSA_TAG_PROTO_YT921X		= DSA_TAG_PROTO_YT921X_VALUE,
 	DSA_TAG_PROTO_MXL_GSW1XX	= DSA_TAG_PROTO_MXL_GSW1XX_VALUE,
+	DSA_TAG_PROTO_KSZ8463		= DSA_TAG_PROTO_KSZ8463_VALUE,
 };
 
 struct dsa_switch;
diff --git a/net/dsa/tag_ksz.c b/net/dsa/tag_ksz.c
index 9170a0148cc43b4213ec4bd8e81d338589671f23..635679402f8a96b29536a91988346a8825bae976 100644
--- a/net/dsa/tag_ksz.c
+++ b/net/dsa/tag_ksz.c
@@ -16,6 +16,7 @@
 #define KSZ9477_NAME "ksz9477"
 #define KSZ9893_NAME "ksz9893"
 #define LAN937X_NAME "lan937x"
+#define KSZ8463_NAME "ksz8463"
 
 /* Typically only one byte is used for tail tag. */
 #define KSZ_PTP_TAG_LEN			4
@@ -383,6 +384,108 @@ static const struct dsa_device_ops ksz9893_netdev_ops = {
 DSA_TAG_DRIVER(ksz9893_netdev_ops);
 MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ9893, KSZ9893_NAME);
 
+#define KSZ8463_TAIL_TAG_PRIO		GENMASK(4, 3)
+#define KSZ8463_TAIL_TAG_EG_PORT_M	GENMASK(2, 0)
+
+static void ksz8463_xmit_timestamp(struct dsa_port *dp, struct sk_buff *skb)
+{
+	struct ksz_tagger_private *priv;
+	struct ptp_header *ptp_hdr;
+	unsigned int ptp_type;
+	u32 tstamp_raw = 0;
+	s64 correction;
+
+	priv = ksz_tagger_private(dp->ds);
+
+	if (!test_bit(KSZ_HWTS_EN, &priv->state))
+		return;
+
+	if (!KSZ_SKB_CB(skb)->update_correction)
+		return;
+
+	ptp_type = KSZ_SKB_CB(skb)->ptp_type;
+	ptp_hdr = ptp_parse_header(skb, ptp_type);
+	if (!ptp_hdr)
+		return;
+
+	correction = (s64)get_unaligned_be64(&ptp_hdr->correction);
+
+	if (correction < 0) {
+		struct timespec64 ts;
+
+		ts = ns_to_timespec64(-correction >> 16);
+		tstamp_raw = ((ts.tv_sec & 3) << 30) | ts.tv_nsec;
+
+		ptp_hdr->reserved2 = tstamp_raw;
+	}
+}
+
+static struct sk_buff *ksz8463_xmit(struct sk_buff *skb,
+				    struct net_device *dev)
+{
+	u16 queue_mapping = skb_get_queue_mapping(skb);
+	u8 prio = netdev_txq_to_tc(dev, queue_mapping);
+	struct dsa_port *dp = dsa_user_to_port(dev);
+	u8 *tag;
+
+	if (skb->ip_summed == CHECKSUM_PARTIAL && skb_checksum_help(skb))
+		return NULL;
+
+	ksz8463_xmit_timestamp(dp, skb);
+
+	tag = skb_put(skb, KSZ_INGRESS_TAG_LEN);
+
+	*tag = BIT(dp->index);
+	*tag |= FIELD_PREP(KSZ8463_TAIL_TAG_PRIO, prio);
+
+	return ksz_defer_xmit(dp, skb);
+}
+
+static struct sk_buff *ksz8463_rcv(struct sk_buff *skb, struct net_device *dev)
+{
+	unsigned int len = KSZ_EGRESS_TAG_LEN;
+	struct ptp_header *ptp_hdr;
+	unsigned int ptp_class;
+	unsigned int port;
+	ktime_t tstamp;
+	u8 *tag;
+
+	if (skb_linearize(skb))
+		return NULL;
+
+	/* Tag decoding */
+	tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN;
+	port = tag[0] & KSZ8463_TAIL_TAG_EG_PORT_M;
+
+	__skb_push(skb, ETH_HLEN);
+	ptp_class = ptp_classify_raw(skb);
+	__skb_pull(skb, ETH_HLEN);
+	if (ptp_class == PTP_CLASS_NONE)
+		goto common_rcv;
+
+	ptp_hdr = ptp_parse_header(skb, ptp_class);
+	if (ptp_hdr) {
+		tstamp = ksz_decode_tstamp(get_unaligned_be32(&ptp_hdr->reserved2));
+		KSZ_SKB_CB(skb)->tstamp = tstamp;
+	}
+
+common_rcv:
+	return ksz_common_rcv(skb, dev, port, len);
+}
+
+static const struct dsa_device_ops ksz8463_netdev_ops = {
+	.name	= KSZ8463_NAME,
+	.proto	= DSA_TAG_PROTO_KSZ8463,
+	.xmit	= ksz8463_xmit,
+	.rcv	= ksz8463_rcv,
+	.connect = ksz_connect,
+	.disconnect = ksz_disconnect,
+	.needed_tailroom = KSZ_INGRESS_TAG_LEN,
+};
+
+DSA_TAG_DRIVER(ksz8463_netdev_ops);
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ8463, KSZ8463_NAME);
+
 /* For xmit, 2/6 bytes are added before FCS.
  * ---------------------------------------------------------------------------
  * DA(6bytes)|SA(6bytes)|....|Data(nbytes)|ts(4bytes)|tag0(1byte)|tag1(1byte)|
@@ -457,6 +560,7 @@ static struct dsa_tag_driver *dsa_tag_driver_array[] = {
 	&DSA_TAG_DRIVER_NAME(ksz9477_netdev_ops),
 	&DSA_TAG_DRIVER_NAME(ksz9893_netdev_ops),
 	&DSA_TAG_DRIVER_NAME(lan937x_netdev_ops),
+	&DSA_TAG_DRIVER_NAME(ksz8463_netdev_ops),
 };
 
 module_dsa_tag_drivers(dsa_tag_driver_array);

-- 
2.52.0

Re: [PATCH net-next 5/8] net: dsa: microchip: Add KSZ8463 tail tag handling

[Maxime Chevallier]

Hi Bastien,

On 15/01/2026 16:57, Bastien Curutchet (Schneider Electric) wrote:
> KSZ8463 uses the KSZ9893 DSA TAG driver. However, the KSZ8463 doesn't
> use the tail tag to convey timestamps to the host as KSZ9893 does. It
> uses the reserved fields in the PTP header instead.

[ ... ]

> +static struct sk_buff *ksz8463_rcv(struct sk_buff *skb, struct net_device *dev)
> +{
> +	unsigned int len = KSZ_EGRESS_TAG_LEN;
> +	struct ptp_header *ptp_hdr;
> +	unsigned int ptp_class;
> +	unsigned int port;
> +	ktime_t tstamp;
> +	u8 *tag;
> +
> +	if (skb_linearize(skb))
> +		return NULL;
> +
> +	/* Tag decoding */
> +	tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN;
> +	port = tag[0] & KSZ8463_TAIL_TAG_EG_PORT_M;
> +
> +	__skb_push(skb, ETH_HLEN);
> +	ptp_class = ptp_classify_raw(skb);
> +	__skb_pull(skb, ETH_HLEN);
> +	if (ptp_class == PTP_CLASS_NONE)
> +		goto common_rcv;
> +
> +	ptp_hdr = ptp_parse_header(skb, ptp_class);
> +	if (ptp_hdr) {
> +		tstamp = ksz_decode_tstamp(get_unaligned_be32(&ptp_hdr->reserved2));
> +		KSZ_SKB_CB(skb)->tstamp = tstamp;

As it is using a reserved field, is it OK to leave this field as-is when forwarding
this skb to userspace, or should it be zeroed first ?

Maxime

Re: [PATCH net-next 5/8] net: dsa: microchip: Add KSZ8463 tail tag handling

[Bastien Curutchet]

Hi Maxime,

On 1/15/26 6:05 PM, Maxime Chevallier wrote:
> Hi Bastien,
> 
> On 15/01/2026 16:57, Bastien Curutchet (Schneider Electric) wrote:
>> KSZ8463 uses the KSZ9893 DSA TAG driver. However, the KSZ8463 doesn't
>> use the tail tag to convey timestamps to the host as KSZ9893 does. It
>> uses the reserved fields in the PTP header instead.
> 
> [ ... ]
> 
>> +static struct sk_buff *ksz8463_rcv(struct sk_buff *skb, struct net_device *dev)
>> +{
>> +	unsigned int len = KSZ_EGRESS_TAG_LEN;
>> +	struct ptp_header *ptp_hdr;
>> +	unsigned int ptp_class;
>> +	unsigned int port;
>> +	ktime_t tstamp;
>> +	u8 *tag;
>> +
>> +	if (skb_linearize(skb))
>> +		return NULL;
>> +
>> +	/* Tag decoding */
>> +	tag = skb_tail_pointer(skb) - KSZ_EGRESS_TAG_LEN;
>> +	port = tag[0] & KSZ8463_TAIL_TAG_EG_PORT_M;
>> +
>> +	__skb_push(skb, ETH_HLEN);
>> +	ptp_class = ptp_classify_raw(skb);
>> +	__skb_pull(skb, ETH_HLEN);
>> +	if (ptp_class == PTP_CLASS_NONE)
>> +		goto common_rcv;
>> +
>> +	ptp_hdr = ptp_parse_header(skb, ptp_class);
>> +	if (ptp_hdr) {
>> +		tstamp = ksz_decode_tstamp(get_unaligned_be32(&ptp_hdr->reserved2));
>> +		KSZ_SKB_CB(skb)->tstamp = tstamp;
> 
> As it is using a reserved field, is it OK to leave this field as-is when forwarding
> this skb to userspace, or should it be zeroed first ?
> 

It doesn't seem to hurt, at least on my test setup (I'm using ptp4l in 
userspace btw), but I agree with you: it feels safer to zero it first. 
I'll do it in next iteration.


Best regards,
Bastien

Re: [PATCH net-next 5/8] net: dsa: microchip: Add KSZ8463 tail tag handling

[Simon Horman]

On Thu, Jan 15, 2026 at 04:57:04PM +0100, Bastien Curutchet (Schneider Electric) wrote:
> KSZ8463 uses the KSZ9893 DSA TAG driver. However, the KSZ8463 doesn't
> use the tail tag to convey timestamps to the host as KSZ9893 does. It
> uses the reserved fields in the PTP header instead.
> 
> Add a KSZ8463-specifig DSA_TAG driver to handle KSZ8463 timestamps.
> There is no information in the tail tag to distinguish PTP packets from
> others so use the ptp_classify_raw() helper to find the PTP packets and
> extract the timestamp from their PTP headers.
> 
> Signed-off-by: Bastien Curutchet (Schneider Electric) <bastien.curutchet@bootlin.com>

...

> diff --git a/net/dsa/tag_ksz.c b/net/dsa/tag_ksz.c
> index 9170a0148cc43b4213ec4bd8e81d338589671f23..635679402f8a96b29536a91988346a8825bae976 100644
> --- a/net/dsa/tag_ksz.c
> +++ b/net/dsa/tag_ksz.c
> @@ -16,6 +16,7 @@
>  #define KSZ9477_NAME "ksz9477"
>  #define KSZ9893_NAME "ksz9893"
>  #define LAN937X_NAME "lan937x"
> +#define KSZ8463_NAME "ksz8463"
>  
>  /* Typically only one byte is used for tail tag. */
>  #define KSZ_PTP_TAG_LEN			4
> @@ -383,6 +384,108 @@ static const struct dsa_device_ops ksz9893_netdev_ops = {
>  DSA_TAG_DRIVER(ksz9893_netdev_ops);
>  MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ9893, KSZ9893_NAME);
>  
> +#define KSZ8463_TAIL_TAG_PRIO		GENMASK(4, 3)
> +#define KSZ8463_TAIL_TAG_EG_PORT_M	GENMASK(2, 0)
> +
> +static void ksz8463_xmit_timestamp(struct dsa_port *dp, struct sk_buff *skb)
> +{
> +	struct ksz_tagger_private *priv;
> +	struct ptp_header *ptp_hdr;
> +	unsigned int ptp_type;
> +	u32 tstamp_raw = 0;
> +	s64 correction;
> +
> +	priv = ksz_tagger_private(dp->ds);
> +
> +	if (!test_bit(KSZ_HWTS_EN, &priv->state))
> +		return;
> +
> +	if (!KSZ_SKB_CB(skb)->update_correction)
> +		return;
> +
> +	ptp_type = KSZ_SKB_CB(skb)->ptp_type;
> +	ptp_hdr = ptp_parse_header(skb, ptp_type);
> +	if (!ptp_hdr)
> +		return;
> +
> +	correction = (s64)get_unaligned_be64(&ptp_hdr->correction);
> +
> +	if (correction < 0) {
> +		struct timespec64 ts;
> +
> +		ts = ns_to_timespec64(-correction >> 16);
> +		tstamp_raw = ((ts.tv_sec & 3) << 30) | ts.tv_nsec;
> +
> +		ptp_hdr->reserved2 = tstamp_raw;

I think that you need to assign a be32 rather than a u32 to reserved2.

Flagged by Sparse [1].

[1] This particular commit, from Al Viro's tree:
    https://git.kernel.org/pub/scm/linux/kernel/git/viro/sparse.git/commit/?id=2634e39bf02697a18fece057208150362c985992
    To address this mess:
    https://lore.kernel.org/all/bf5b9a62-a120-421e-908d-1404c42e0b60@kernel.org/

> +	}
> +}

...

Re: [PATCH net-next 5/8] net: dsa: microchip: Add KSZ8463 tail tag handling

[Bastien Curutchet]

Hi Simon,

On 1/20/26 6:17 PM, Simon Horman wrote:
> On Thu, Jan 15, 2026 at 04:57:04PM +0100, Bastien Curutchet (Schneider Electric) wrote:
>> KSZ8463 uses the KSZ9893 DSA TAG driver. However, the KSZ8463 doesn't
>> use the tail tag to convey timestamps to the host as KSZ9893 does. It
>> uses the reserved fields in the PTP header instead.
>>
>> Add a KSZ8463-specifig DSA_TAG driver to handle KSZ8463 timestamps.
>> There is no information in the tail tag to distinguish PTP packets from
>> others so use the ptp_classify_raw() helper to find the PTP packets and
>> extract the timestamp from their PTP headers.
>>
>> Signed-off-by: Bastien Curutchet (Schneider Electric) <bastien.curutchet@bootlin.com>
> 
> ...
> 
>> diff --git a/net/dsa/tag_ksz.c b/net/dsa/tag_ksz.c
>> index 9170a0148cc43b4213ec4bd8e81d338589671f23..635679402f8a96b29536a91988346a8825bae976 100644
>> --- a/net/dsa/tag_ksz.c
>> +++ b/net/dsa/tag_ksz.c
>> @@ -16,6 +16,7 @@
>>   #define KSZ9477_NAME "ksz9477"
>>   #define KSZ9893_NAME "ksz9893"
>>   #define LAN937X_NAME "lan937x"
>> +#define KSZ8463_NAME "ksz8463"
>>   
>>   /* Typically only one byte is used for tail tag. */
>>   #define KSZ_PTP_TAG_LEN			4
>> @@ -383,6 +384,108 @@ static const struct dsa_device_ops ksz9893_netdev_ops = {
>>   DSA_TAG_DRIVER(ksz9893_netdev_ops);
>>   MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ9893, KSZ9893_NAME);
>>   
>> +#define KSZ8463_TAIL_TAG_PRIO		GENMASK(4, 3)
>> +#define KSZ8463_TAIL_TAG_EG_PORT_M	GENMASK(2, 0)
>> +
>> +static void ksz8463_xmit_timestamp(struct dsa_port *dp, struct sk_buff *skb)
>> +{
>> +	struct ksz_tagger_private *priv;
>> +	struct ptp_header *ptp_hdr;
>> +	unsigned int ptp_type;
>> +	u32 tstamp_raw = 0;
>> +	s64 correction;
>> +
>> +	priv = ksz_tagger_private(dp->ds);
>> +
>> +	if (!test_bit(KSZ_HWTS_EN, &priv->state))
>> +		return;
>> +
>> +	if (!KSZ_SKB_CB(skb)->update_correction)
>> +		return;
>> +
>> +	ptp_type = KSZ_SKB_CB(skb)->ptp_type;
>> +	ptp_hdr = ptp_parse_header(skb, ptp_type);
>> +	if (!ptp_hdr)
>> +		return;
>> +
>> +	correction = (s64)get_unaligned_be64(&ptp_hdr->correction);
>> +
>> +	if (correction < 0) {
>> +		struct timespec64 ts;
>> +
>> +		ts = ns_to_timespec64(-correction >> 16);
>> +		tstamp_raw = ((ts.tv_sec & 3) << 30) | ts.tv_nsec;
>> +
>> +		ptp_hdr->reserved2 = tstamp_raw;
> 
> I think that you need to assign a be32 rather than a u32 to reserved2.
> 

Indeed. By testing this back, I realize that this is only needed by the 
one-step mode. This series only adds support for two-step so I'll just 
remove this part.


Best regards,
Bastien

Re: [PATCH net-next 5/8] net: dsa: microchip: Add KSZ8463 tail tag handling

[Simon Horman]

On Thu, Jan 22, 2026 at 01:59:21PM +0100, Bastien Curutchet wrote:
> Hi Simon,
> 
> On 1/20/26 6:17 PM, Simon Horman wrote:
> > On Thu, Jan 15, 2026 at 04:57:04PM +0100, Bastien Curutchet (Schneider Electric) wrote:
> > > KSZ8463 uses the KSZ9893 DSA TAG driver. However, the KSZ8463 doesn't
> > > use the tail tag to convey timestamps to the host as KSZ9893 does. It
> > > uses the reserved fields in the PTP header instead.
> > > 
> > > Add a KSZ8463-specifig DSA_TAG driver to handle KSZ8463 timestamps.
> > > There is no information in the tail tag to distinguish PTP packets from
> > > others so use the ptp_classify_raw() helper to find the PTP packets and
> > > extract the timestamp from their PTP headers.
> > > 
> > > Signed-off-by: Bastien Curutchet (Schneider Electric) <bastien.curutchet@bootlin.com>
> > 
> > ...
> > 
> > > diff --git a/net/dsa/tag_ksz.c b/net/dsa/tag_ksz.c
> > > index 9170a0148cc43b4213ec4bd8e81d338589671f23..635679402f8a96b29536a91988346a8825bae976 100644
> > > --- a/net/dsa/tag_ksz.c
> > > +++ b/net/dsa/tag_ksz.c
> > > @@ -16,6 +16,7 @@
> > >   #define KSZ9477_NAME "ksz9477"
> > >   #define KSZ9893_NAME "ksz9893"
> > >   #define LAN937X_NAME "lan937x"
> > > +#define KSZ8463_NAME "ksz8463"
> > >   /* Typically only one byte is used for tail tag. */
> > >   #define KSZ_PTP_TAG_LEN			4
> > > @@ -383,6 +384,108 @@ static const struct dsa_device_ops ksz9893_netdev_ops = {
> > >   DSA_TAG_DRIVER(ksz9893_netdev_ops);
> > >   MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KSZ9893, KSZ9893_NAME);
> > > +#define KSZ8463_TAIL_TAG_PRIO		GENMASK(4, 3)
> > > +#define KSZ8463_TAIL_TAG_EG_PORT_M	GENMASK(2, 0)
> > > +
> > > +static void ksz8463_xmit_timestamp(struct dsa_port *dp, struct sk_buff *skb)
> > > +{
> > > +	struct ksz_tagger_private *priv;
> > > +	struct ptp_header *ptp_hdr;
> > > +	unsigned int ptp_type;
> > > +	u32 tstamp_raw = 0;
> > > +	s64 correction;
> > > +
> > > +	priv = ksz_tagger_private(dp->ds);
> > > +
> > > +	if (!test_bit(KSZ_HWTS_EN, &priv->state))
> > > +		return;
> > > +
> > > +	if (!KSZ_SKB_CB(skb)->update_correction)
> > > +		return;
> > > +
> > > +	ptp_type = KSZ_SKB_CB(skb)->ptp_type;
> > > +	ptp_hdr = ptp_parse_header(skb, ptp_type);
> > > +	if (!ptp_hdr)
> > > +		return;
> > > +
> > > +	correction = (s64)get_unaligned_be64(&ptp_hdr->correction);
> > > +
> > > +	if (correction < 0) {
> > > +		struct timespec64 ts;
> > > +
> > > +		ts = ns_to_timespec64(-correction >> 16);
> > > +		tstamp_raw = ((ts.tv_sec & 3) << 30) | ts.tv_nsec;
> > > +
> > > +		ptp_hdr->reserved2 = tstamp_raw;
> > 
> > I think that you need to assign a be32 rather than a u32 to reserved2.
> > 
> 
> Indeed. By testing this back, I realize that this is only needed by the
> one-step mode. This series only adds support for two-step so I'll just
> remove this part.

Great, thanks.

[PATCH net-next 6/8] net: dsa: microchip: Enable Ethernet PTP detection

[Bastien Curutchet (Schneider Electric)]

KSZ8463 needs to enable the Ethernet PTP detection to fire the
interrupts when a timestamp is captured.

Enable Ethernet PTP detection.

Signed-off-by: Bastien Curutchet (Schneider Electric) <bastien.curutchet@bootlin.com>
---
 drivers/net/dsa/microchip/ksz_ptp.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/dsa/microchip/ksz_ptp.c b/drivers/net/dsa/microchip/ksz_ptp.c
index cafb64785ef4c7eb9c05900a87148e8b7b4678e5..fcc2a7d50909c4e6a8cf87a3013c3c311c1714b0 100644
--- a/drivers/net/dsa/microchip/ksz_ptp.c
+++ b/drivers/net/dsa/microchip/ksz_ptp.c
@@ -947,8 +947,8 @@ int ksz_ptp_clock_register(struct dsa_switch *ds)
 	/* Currently only P2P mode is supported. When 802_1AS bit is set, it
 	 * forwards all PTP packets to host port and none to other ports.
 	 */
-	ret = ksz_rmw16(dev, regs[PTP_MSG_CONF1], PTP_TC_P2P | PTP_802_1AS,
-			PTP_TC_P2P | PTP_802_1AS);
+	ret = ksz_rmw16(dev, regs[PTP_MSG_CONF1], PTP_TC_P2P | PTP_802_1AS | PTP_ETH_ENABLE,
+			PTP_TC_P2P | PTP_802_1AS | PTP_ETH_ENABLE);
 	if (ret)
 		return ret;
 

-- 
2.52.0

[PATCH net-next 7/8] net: dsa: microchip: Adapt port offset for KSZ8463's PTP register

[Bastien Curutchet (Schneider Electric)]

In KSZ8463 register's layout, the offset between port 1 and port 2
registers isn't the same in the generic control register area than in
the PTP register area. The get_port_addr() always uses the same offset
so it doesn't work when it's used to access PTP registers.

Adapt the port offset in get_port_addr() when the accessed register is
in the PTP area.

Signed-off-by: Bastien Curutchet (Schneider Electric) <bastien.curutchet@bootlin.com>
---
 drivers/net/dsa/microchip/ksz8.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/dsa/microchip/ksz8.c b/drivers/net/dsa/microchip/ksz8.c
index c354abdafc1b542a32c276ef939a90db30c67f55..a05527899b8bab6d53509ba38c58101b79e98ee5 100644
--- a/drivers/net/dsa/microchip/ksz8.c
+++ b/drivers/net/dsa/microchip/ksz8.c
@@ -2020,6 +2020,9 @@ u32 ksz8_get_port_addr(int port, int offset)
 
 u32 ksz8463_get_port_addr(int port, int offset)
 {
+	if (offset >= KSZ8463_PTP_CLK_CTRL)
+		return offset + 0x20 * port;
+
 	return offset + 0x18 * port;
 }
 

-- 
2.52.0

[PATCH net-next 8/8] net: dsa: microchip: Add two-step PTP support for KSZ8463

[Bastien Curutchet (Schneider Electric)]

The KSZ8463 switch supports PTP but it's not supported by driver.

Add L2 two-step PTP support for the KSZ8463. IPv4 and IPv6 layers aren't
supported. Neither is one-step PTP.

The pdelay_req and pdelay_resp timestamps share one interrupt bit status.
So introduce last_tx_is_pdelayresp to keep track of the last sent event
type. Use it to retrieve the relevant timestamp when the interrupt is
caught.

Signed-off-by: Bastien Curutchet (Schneider Electric) <bastien.curutchet@bootlin.com>
---
 drivers/net/dsa/microchip/ksz8.c        | 15 ++--------
 drivers/net/dsa/microchip/ksz8_reg.h    |  1 +
 drivers/net/dsa/microchip/ksz_common.c  |  1 +
 drivers/net/dsa/microchip/ksz_common.h  |  1 +
 drivers/net/dsa/microchip/ksz_ptp.c     | 52 ++++++++++++++++++++++++++-------
 drivers/net/dsa/microchip/ksz_ptp_reg.h |  4 +++
 6 files changed, 50 insertions(+), 24 deletions(-)

diff --git a/drivers/net/dsa/microchip/ksz8.c b/drivers/net/dsa/microchip/ksz8.c
index a05527899b8bab6d53509ba38c58101b79e98ee5..cec76965def71320abeb77f550f37af7dcb96d63 100644
--- a/drivers/net/dsa/microchip/ksz8.c
+++ b/drivers/net/dsa/microchip/ksz8.c
@@ -143,9 +143,9 @@ int ksz8_reset_switch(struct ksz_device *dev)
 			KSZ8863_GLOBAL_SOFTWARE_RESET | KSZ8863_PCS_RESET, false);
 	} else if (ksz_is_ksz8463(dev)) {
 		ksz_cfg(dev, KSZ8463_REG_SW_RESET,
-			KSZ8463_GLOBAL_SOFTWARE_RESET, true);
+			KSZ8463_GLOBAL_SOFTWARE_RESET | KSZ8463_PTP_SOFTWARE_RESET, true);
 		ksz_cfg(dev, KSZ8463_REG_SW_RESET,
-			KSZ8463_GLOBAL_SOFTWARE_RESET, false);
+			KSZ8463_GLOBAL_SOFTWARE_RESET | KSZ8463_PTP_SOFTWARE_RESET, false);
 	} else {
 		/* reset switch */
 		ksz_write8(dev, REG_POWER_MANAGEMENT_1,
@@ -1762,17 +1762,6 @@ void ksz8_config_cpu_port(struct dsa_switch *ds)
 					   KSZ8463_REG_DSP_CTRL_6,
 					   COPPER_RECEIVE_ADJUSTMENT, 0);
 		}
-
-		/* Turn off PTP function as the switch's proprietary way of
-		 * handling timestamp is not supported in current Linux PTP
-		 * stack implementation.
-		 */
-		regmap_update_bits(ksz_regmap_16(dev),
-				   KSZ8463_PTP_MSG_CONF1,
-				   PTP_ENABLE, 0);
-		regmap_update_bits(ksz_regmap_16(dev),
-				   KSZ8463_PTP_CLK_CTRL,
-				   PTP_CLK_ENABLE, 0);
 	}
 }
 
diff --git a/drivers/net/dsa/microchip/ksz8_reg.h b/drivers/net/dsa/microchip/ksz8_reg.h
index 332408567b473c141c3695328a524f257f2cfc70..0558740ae57738fa7e4a8f3f429254033c54af12 100644
--- a/drivers/net/dsa/microchip/ksz8_reg.h
+++ b/drivers/net/dsa/microchip/ksz8_reg.h
@@ -765,6 +765,7 @@
 #define KSZ8463_REG_SW_RESET		0x126
 
 #define KSZ8463_GLOBAL_SOFTWARE_RESET	BIT(0)
+#define KSZ8463_PTP_SOFTWARE_RESET	BIT(2)
 
 #define KSZ8463_PTP_CLK_CTRL		0x600
 
diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c
index 5141343d2f40bbd380c0b52f6919b842fb71a8fd..55e3fa4791078cb099e236e6e5a29515727ed8ab 100644
--- a/drivers/net/dsa/microchip/ksz_common.c
+++ b/drivers/net/dsa/microchip/ksz_common.c
@@ -1512,6 +1512,7 @@ const struct ksz_chip_data ksz_switch_chips[] = {
 		.supports_mii = {false, false, true},
 		.supports_rmii = {false, false, true},
 		.internal_phy = {true, true, false},
+		.ptp_capable = true,
 	},
 
 	[KSZ8563] = {
diff --git a/drivers/net/dsa/microchip/ksz_common.h b/drivers/net/dsa/microchip/ksz_common.h
index dfbc3d13daca8d7a8b9d3ffe6a7c1ec9927863f2..1fface82086eed87749d4702b046fcab313663e9 100644
--- a/drivers/net/dsa/microchip/ksz_common.h
+++ b/drivers/net/dsa/microchip/ksz_common.h
@@ -150,6 +150,7 @@ struct ksz_port {
 	struct kernel_hwtstamp_config tstamp_config;
 	bool hwts_tx_en;
 	bool hwts_rx_en;
+	bool last_tx_is_pdelayresp;
 	struct ksz_irq ptpirq;
 	struct ksz_ptp_irq ptpmsg_irq[3];
 	ktime_t tstamp_msg;
diff --git a/drivers/net/dsa/microchip/ksz_ptp.c b/drivers/net/dsa/microchip/ksz_ptp.c
index fcc2a7d50909c4e6a8cf87a3013c3c311c1714b0..dc77c83dc049f16f76e3138708f5cbd70ad70367 100644
--- a/drivers/net/dsa/microchip/ksz_ptp.c
+++ b/drivers/net/dsa/microchip/ksz_ptp.c
@@ -308,15 +308,20 @@ int ksz_get_ts_info(struct dsa_switch *ds, int port, struct kernel_ethtool_ts_in
 			      SOF_TIMESTAMPING_RX_HARDWARE |
 			      SOF_TIMESTAMPING_RAW_HARDWARE;
 
-	ts->tx_types = BIT(HWTSTAMP_TX_OFF) | BIT(HWTSTAMP_TX_ONESTEP_P2P);
+	ts->tx_types = BIT(HWTSTAMP_TX_OFF);
 
-	if (is_lan937x(dev))
+	if (!ksz_is_ksz8463(dev))
+		ts->tx_types |= BIT(HWTSTAMP_TX_ONESTEP_P2P);
+
+	if (is_lan937x(dev) || ksz_is_ksz8463(dev))
 		ts->tx_types |= BIT(HWTSTAMP_TX_ON);
 
 	ts->rx_filters = BIT(HWTSTAMP_FILTER_NONE) |
-			 BIT(HWTSTAMP_FILTER_PTP_V2_L4_EVENT) |
-			 BIT(HWTSTAMP_FILTER_PTP_V2_L2_EVENT) |
-			 BIT(HWTSTAMP_FILTER_PTP_V2_EVENT);
+			 BIT(HWTSTAMP_FILTER_PTP_V2_L2_EVENT);
+	if (!ksz_is_ksz8463(dev)) {
+		ts->rx_filters |= BIT(HWTSTAMP_FILTER_PTP_V2_L4_EVENT) |
+				  BIT(HWTSTAMP_FILTER_PTP_V2_EVENT);
+	}
 
 	ts->phc_index = ptp_clock_index(ptp_data->clock);
 
@@ -353,6 +358,9 @@ static int ksz_set_hwtstamp_config(struct ksz_device *dev,
 		prt->hwts_tx_en = false;
 		break;
 	case HWTSTAMP_TX_ONESTEP_P2P:
+		if (ksz_is_ksz8463(dev))
+			return -ERANGE;
+
 		prt->ptpmsg_irq[KSZ_SYNC_MSG].ts_en  = false;
 		prt->ptpmsg_irq[KSZ_XDREQ_MSG].ts_en = true;
 		prt->ptpmsg_irq[KSZ_PDRES_MSG].ts_en = false;
@@ -364,14 +372,19 @@ static int ksz_set_hwtstamp_config(struct ksz_device *dev,
 
 		break;
 	case HWTSTAMP_TX_ON:
-		if (!is_lan937x(dev))
+		if (!is_lan937x(dev) && !ksz_is_ksz8463(dev))
 			return -ERANGE;
 
-		prt->ptpmsg_irq[KSZ_SYNC_MSG].ts_en  = true;
-		prt->ptpmsg_irq[KSZ_XDREQ_MSG].ts_en = true;
-		prt->ptpmsg_irq[KSZ_PDRES_MSG].ts_en = true;
-		prt->hwts_tx_en = true;
+		if (ksz_is_ksz8463(dev)) {
+			prt->ptpmsg_irq[KSZ8463_SYNC_MSG].ts_en  = true;
+			prt->ptpmsg_irq[KSZ8463_XDREQ_PDRES_MSG].ts_en = true;
+		} else {
+			prt->ptpmsg_irq[KSZ_SYNC_MSG].ts_en  = true;
+			prt->ptpmsg_irq[KSZ_XDREQ_MSG].ts_en = true;
+			prt->ptpmsg_irq[KSZ_PDRES_MSG].ts_en = true;
+		}
 
+		prt->hwts_tx_en = true;
 		ret = ksz_rmw16(dev, regs[PTP_MSG_CONF1], PTP_1STEP, 0);
 		if (ret)
 			return ret;
@@ -387,6 +400,8 @@ static int ksz_set_hwtstamp_config(struct ksz_device *dev,
 		break;
 	case HWTSTAMP_FILTER_PTP_V2_L4_EVENT:
 	case HWTSTAMP_FILTER_PTP_V2_L4_SYNC:
+		if (ksz_is_ksz8463(dev))
+			return -ERANGE;
 		config->rx_filter = HWTSTAMP_FILTER_PTP_V2_L4_EVENT;
 		prt->hwts_rx_en = true;
 		break;
@@ -397,6 +412,8 @@ static int ksz_set_hwtstamp_config(struct ksz_device *dev,
 		break;
 	case HWTSTAMP_FILTER_PTP_V2_EVENT:
 	case HWTSTAMP_FILTER_PTP_V2_SYNC:
+		if (ksz_is_ksz8463(dev))
+			return -ERANGE;
 		config->rx_filter = HWTSTAMP_FILTER_PTP_V2_EVENT;
 		prt->hwts_rx_en = true;
 		break;
@@ -518,6 +535,8 @@ void ksz_port_txtstamp(struct dsa_switch *ds, int port, struct sk_buff *skb)
 	if (!hdr)
 		return;
 
+	prt->last_tx_is_pdelayresp = false;
+
 	ptp_msg_type = ptp_get_msgtype(hdr, type);
 
 	switch (ptp_msg_type) {
@@ -528,6 +547,7 @@ void ksz_port_txtstamp(struct dsa_switch *ds, int port, struct sk_buff *skb)
 	case PTP_MSGTYPE_PDELAY_REQ:
 		break;
 	case PTP_MSGTYPE_PDELAY_RESP:
+		prt->last_tx_is_pdelayresp = true;
 		if (prt->tstamp_config.tx_type == HWTSTAMP_TX_ONESTEP_P2P) {
 			KSZ_SKB_CB(skb)->ptp_type = type;
 			KSZ_SKB_CB(skb)->update_correction = true;
@@ -972,7 +992,17 @@ void ksz_ptp_clock_unregister(struct dsa_switch *ds)
 
 static int ksz_read_ts(struct ksz_port *port, u16 reg, u32 *ts)
 {
-	return ksz_read32(port->ksz_dev, reg, ts);
+	u16 ts_reg = reg;
+
+	/**
+	 * On KSZ8463 DREQ and DRESP timestamps share one interrupt line
+	 * so we have to check the nature of the latest event sent to know
+	 * where the timestamp is located
+	 */
+	if (ksz_is_ksz8463(port->ksz_dev) && port->last_tx_is_pdelayresp)
+		ts_reg += KSZ8463_DRESP_TS_OFFSET;
+
+	return ksz_read32(port->ksz_dev, ts_reg, ts);
 }
 
 static irqreturn_t ksz_ptp_msg_thread_fn(int irq, void *dev_id)
diff --git a/drivers/net/dsa/microchip/ksz_ptp_reg.h b/drivers/net/dsa/microchip/ksz_ptp_reg.h
index e80fb4bd1a0e970ba3570374d3dc82c8e2cc15b4..ac9d0f2b348b0469abbeed0e645fe8ef441d35fb 100644
--- a/drivers/net/dsa/microchip/ksz_ptp_reg.h
+++ b/drivers/net/dsa/microchip/ksz_ptp_reg.h
@@ -125,6 +125,10 @@
 #define KSZ8463_REG_PORT_SYNC_TS	0x064C
 #define KSZ8463_REG_PORT_DRESP_TS	0x0650
 
+#define KSZ8463_DRESP_TS_OFFSET		(KSZ8463_REG_PORT_DRESP_TS - KSZ8463_REG_PORT_DREQ_TS)
+#define KSZ8463_SYNC_MSG		0
+#define KSZ8463_XDREQ_PDRES_MSG		1
+
 #define REG_PTP_PORT_TX_INT_STATUS__2	0x0C14
 #define REG_PTP_PORT_TX_INT_ENABLE__2	0x0C16
 

-- 
2.52.0