From: Tristram Ha <tristram.ha@microchip.com>

ksz8873_valid_regs[] was added for register access for KSZ8863/KSZ8873
switches, but the reset register is not in the list so
ksz8_reset_switch() does not take any effect.

Replace regmap_update_bits() using ksz_regmap_8 with ksz_rmw8() so that
an error message will be given if the register is not defined.

A side effect of not resetting the switch is the static MAC table is not
cleared.  Further additions to the table will show write error as there
are only 8 entries in the table.

Fixes: d0dec3333040 ("net: dsa: microchip: Add register access control for KSZ8873 chip")
Signed-off-by: Tristram Ha <tristram.ha@microchip.com>
---
v2
- Use ksz_rmw8() to display error message

 drivers/net/dsa/microchip/ksz8.c       | 20 +++++++++++---------
 drivers/net/dsa/microchip/ksz_common.c |  1 +
 2 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/drivers/net/dsa/microchip/ksz8.c b/drivers/net/dsa/microchip/ksz8.c
index 76e490070e9c..c354abdafc1b 100644
--- a/drivers/net/dsa/microchip/ksz8.c
+++ b/drivers/net/dsa/microchip/ksz8.c
@@ -36,15 +36,14 @@
 
 static void ksz_cfg(struct ksz_device *dev, u32 addr, u8 bits, bool set)
 {
-	regmap_update_bits(ksz_regmap_8(dev), addr, bits, set ? bits : 0);
+	ksz_rmw8(dev, addr, bits, set ? bits : 0);
 }
 
 static void ksz_port_cfg(struct ksz_device *dev, int port, int offset, u8 bits,
 			 bool set)
 {
-	regmap_update_bits(ksz_regmap_8(dev),
-			   dev->dev_ops->get_port_addr(port, offset),
-			   bits, set ? bits : 0);
+	ksz_rmw8(dev, dev->dev_ops->get_port_addr(port, offset), bits,
+		 set ? bits : 0);
 }
 
 /**
@@ -1955,16 +1954,19 @@ int ksz8_setup(struct dsa_switch *ds)
 	ksz_cfg(dev, S_LINK_AGING_CTRL, SW_LINK_AUTO_AGING, true);
 
 	/* Enable aggressive back off algorithm in half duplex mode. */
-	regmap_update_bits(ksz_regmap_8(dev), REG_SW_CTRL_1,
-			   SW_AGGR_BACKOFF, SW_AGGR_BACKOFF);
+	ret = ksz_rmw8(dev, REG_SW_CTRL_1, SW_AGGR_BACKOFF, SW_AGGR_BACKOFF);
+	if (ret)
+		return ret;
 
 	/*
 	 * Make sure unicast VLAN boundary is set as default and
 	 * enable no excessive collision drop.
 	 */
-	regmap_update_bits(ksz_regmap_8(dev), REG_SW_CTRL_2,
-			   UNICAST_VLAN_BOUNDARY | NO_EXC_COLLISION_DROP,
-			   UNICAST_VLAN_BOUNDARY | NO_EXC_COLLISION_DROP);
+	ret = ksz_rmw8(dev, REG_SW_CTRL_2,
+		       UNICAST_VLAN_BOUNDARY | NO_EXC_COLLISION_DROP,
+		       UNICAST_VLAN_BOUNDARY | NO_EXC_COLLISION_DROP);
+	if (ret)
+		return ret;
 
 	ksz_cfg(dev, S_REPLACE_VID_CTRL, SW_REPLACE_VID, false);
 
diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c
index 7292bfe2f7ca..4cb14288ff0f 100644
--- a/drivers/net/dsa/microchip/ksz_common.c
+++ b/drivers/net/dsa/microchip/ksz_common.c
@@ -1447,6 +1447,7 @@ static const struct regmap_range ksz8873_valid_regs[] = {
 	regmap_reg_range(0x3f, 0x3f),
 
 	/* advanced control registers */
+	regmap_reg_range(0x43, 0x43),
 	regmap_reg_range(0x60, 0x6f),
 	regmap_reg_range(0x70, 0x75),
 	regmap_reg_range(0x76, 0x78),
-- 
2.34.1

On Wed, Aug 06, 2025 at 05:54:53PM -0700, Tristram.Ha@microchip.com wrote:
> From: Tristram Ha <tristram.ha@microchip.com>
> 
> ksz8873_valid_regs[] was added for register access for KSZ8863/KSZ8873
> switches, but the reset register is not in the list so
> ksz8_reset_switch() does not take any effect.
> 
> Replace regmap_update_bits() using ksz_regmap_8 with ksz_rmw8() so that
> an error message will be given if the register is not defined.
> 
> A side effect of not resetting the switch is the static MAC table is not
> cleared.  Further additions to the table will show write error as there
> are only 8 entries in the table.
> 
> Fixes: d0dec3333040 ("net: dsa: microchip: Add register access control for KSZ8873 chip")
> Signed-off-by: Tristram Ha <tristram.ha@microchip.com>

Reviewed-by: Oleksij Rempel <o.rempel@pengutronix.de>

Thank you!

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