@@ -632,6 +632,57 @@ static void ksz8_w_vlan_table(struct ksz_device *dev, u16 vid, u16 vlan)
ksz8_w_table(dev, TABLE_VLAN, addr, buf);
}
+/**
+ * ksz879x_get_loopback - KSZ879x specific function to get loopback
+ * configuration status for a specific port
+ * @dev: Pointer to the device structure
+ * @port: Port number to query
+ * @val: Pointer to store the result
+ *
+ * This function reads the SMI registers to determine whether loopback mode
+ * is enabled for a specific port.
+ *
+ * Return: 0 on success, error code on failure.
+ */
+static int ksz879x_get_loopback(struct ksz_device *dev, u16 port,
+ u16 *val)
+{
+ u8 stat3;
+ int ret;
+
+ ret = ksz_pread8(dev, port, REG_PORT_STATUS_3, &stat3);
+ if (ret)
+ return ret;
+
+ if (stat3 & PORT_PHY_LOOPBACK)
+ *val |= BMCR_LOOPBACK;
+
+ return 0;
+}
+
+/**
+ * ksz879x_set_loopback - KSZ879x specific function to set loopback mode for
+ * a specific port
+ * @dev: Pointer to the device structure.
+ * @port: Port number to modify.
+ * @val: Value indicating whether to enable or disable loopback mode.
+ *
+ * This function translates loopback bit of the BMCR register into the
+ * corresponding hardware register bit value and writes it to the SMI interface.
+ *
+ * Return: 0 on success, error code on failure.
+ */
+static int ksz879x_set_loopback(struct ksz_device *dev, u16 port, u16 val)
+{
+ u8 stat3 = 0;
+
+ if (val & BMCR_LOOPBACK)
+ stat3 |= PORT_PHY_LOOPBACK;
+
+ return ksz_prmw8(dev, port, REG_PORT_STATUS_3, PORT_PHY_LOOPBACK,
+ stat3);
+}
+
/**
* ksz8_r_phy_ctrl - Translates and reads from the SMI interface to a MIIM PHY
* Control register (Reg. 31).
@@ -731,16 +782,20 @@ static int ksz8_r_phy_bmcr(struct ksz_device *dev, u16 port, u16 *val)
if (ret)
return ret;
- if (restart & PORT_PHY_LOOPBACK)
- *val |= BMCR_LOOPBACK;
-
if (ctrl & PORT_FORCE_100_MBIT)
*val |= BMCR_SPEED100;
if (ksz_is_ksz88x3(dev)) {
+ if (restart & KSZ8873_PORT_PHY_LOOPBACK)
+ *val |= BMCR_LOOPBACK;
+
if ((ctrl & PORT_AUTO_NEG_ENABLE))
*val |= BMCR_ANENABLE;
} else {
+ ret = ksz879x_get_loopback(dev, port, val);
+ if (ret)
+ return ret;
+
if (!(ctrl & PORT_AUTO_NEG_DISABLE))
*val |= BMCR_ANENABLE;
}
@@ -1001,8 +1056,7 @@ static int ksz8_w_phy_bmcr(struct ksz_device *dev, u16 port, u16 val)
restart = 0;
restart_mask = PORT_LED_OFF | PORT_TX_DISABLE | PORT_AUTO_NEG_RESTART |
- PORT_POWER_DOWN | PORT_AUTO_MDIX_DISABLE | PORT_FORCE_MDIX |
- PORT_PHY_LOOPBACK;
+ PORT_POWER_DOWN | PORT_AUTO_MDIX_DISABLE | PORT_FORCE_MDIX;
if (val & KSZ886X_BMCR_DISABLE_LED)
restart |= PORT_LED_OFF;
@@ -1022,8 +1076,16 @@ static int ksz8_w_phy_bmcr(struct ksz_device *dev, u16 port, u16 val)
if (val & KSZ886X_BMCR_FORCE_MDI)
restart |= PORT_FORCE_MDIX;
- if (val & BMCR_LOOPBACK)
- restart |= PORT_PHY_LOOPBACK;
+ if (ksz_is_ksz88x3(dev)) {
+ restart_mask |= KSZ8873_PORT_PHY_LOOPBACK;
+
+ if (val & BMCR_LOOPBACK)
+ restart |= KSZ8873_PORT_PHY_LOOPBACK;
+ } else {
+ ret = ksz879x_set_loopback(dev, port, val);
+ if (ret)
+ return ret;
+ }
return ksz_prmw8(dev, port, regs[P_NEG_RESTART_CTRL], restart_mask,
restart);
@@ -265,6 +265,7 @@
#define PORT_AUTO_MDIX_DISABLE BIT(2)
#define PORT_FORCE_MDIX BIT(1)
#define PORT_MAC_LOOPBACK BIT(0)
+#define KSZ8873_PORT_PHY_LOOPBACK BIT(0)
#define REG_PORT_1_STATUS_2 0x1E
#define REG_PORT_2_STATUS_2 0x2E
Correct the PHY loopback bit handling in the ksz8_w_phy_bmcr and ksz8_r_phy_bmcr functions for KSZ8794 and KSZ8873 variants in the ksz8795 driver. Previously, the code erroneously used Bit 7 of port register 0xD for both chip variants, which is actually for LED configuration. This update ensures the correct registers and bits are used for the PHY loopback feature: - For KSZ8794: Use 0xF / Bit 7. - For KSZ8873: Use 0xD / Bit 0. The lack of loopback support was seen on KSZ8873 system by using "ethtool -t lanX". After this patch, the ethtool selftest will work, but only if port is not part of a bridge. Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de> --- drivers/net/dsa/microchip/ksz8795.c | 76 ++++++++++++++++++++++--- drivers/net/dsa/microchip/ksz8795_reg.h | 1 + 2 files changed, 70 insertions(+), 7 deletions(-)