[RFC PATCH v1 9/9] net: phy: micrel: add patch for erratas on port1

Oleksij Rempel
2021-05-05T09:22:18Z

From: Michael Grzeschik <m.grzeschik@pengutronix.de>

The micrel switch ksz8873 has the following errata [1]:

* Module 1: LinkMD does not work on Port 1
* Module 4: Port 1 does not respond to received flow control PAUSE frames

This patch disables the support on the defective port.

[1] http://ww1.microchip.com/downloads/en/DeviceDoc/KSZ8873-Errata-DS80000830A.pdf

Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
---
drivers/net/dsa/microchip/ksz8795.c | 13 +++++++++++++
drivers/net/phy/micrel.c | 3 +++
drivers/net/phy/phylink.c | 2 +-
include/linux/micrel_phy.h | 1 +
net/dsa/slave.c | 4 ++++
5 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/drivers/net/dsa/microchip/ksz8795.c b/drivers/net/dsa/microchip/ksz8795.c
index fb47be0c2154..42b7ef36f24f 100644
--- a/drivers/net/dsa/microchip/ksz8795.c
+++ b/drivers/net/dsa/microchip/ksz8795.c
@@ -966,6 +966,18 @@ static enum dsa_tag_protocol ksz8_get_tag_protocol(struct dsa_switch *ds,
DSA_TAG_PROTO_KSZ9893 : DSA_TAG_PROTO_KSZ8795;
}

+static u32 ksz8_sw_get_phy_flags(struct dsa_switch *ds, int port)
+{
+ /* Silicon Errata Sheet (DS80000830A):
+ * Port 1 does not work with LinkMD Cable-Testing.
+ * Port 1 does not respond to received PAUSE control frames.
+ */
+ if (!port)
+ return MICREL_KSZ8_P1_ERRATA;
+
+ return 0;
+}
+
static void ksz8_get_strings(struct dsa_switch *ds, int port,
u32 stringset, uint8_t *buf)
{
@@ -1516,6 +1528,7 @@ static void ksz_validate(struct dsa_switch *ds, int port,

static const struct dsa_switch_ops ksz8_switch_ops = {
.get_tag_protocol = ksz8_get_tag_protocol,
+ .get_phy_flags = ksz8_sw_get_phy_flags,
.setup = ksz8_setup,
.phy_read = ksz_phy_read16,
.phy_write = ksz_phy_write16,
diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
index f0ca7b53bcf9..dbdc0926386e 100644
--- a/drivers/net/phy/micrel.c
+++ b/drivers/net/phy/micrel.c
@@ -1414,6 +1414,9 @@ static int kszphy_probe(struct phy_device *phydev)

static int ksz886x_cable_test_start(struct phy_device *phydev)
{
+ if (phydev->dev_flags & MICREL_KSZ8_P1_ERRATA)
+ return -ENOTSUPP;
+
/* If autoneg is enabled, we won't be able to test cross pair
* short. In this case, the PHY will "detect" a link and
* confuse the internal state machine - disable auto neg here.
diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
index 96d8e88b4e46..167c2277814f 100644
--- a/drivers/net/phy/phylink.c
+++ b/drivers/net/phy/phylink.c
@@ -1029,7 +1029,7 @@ static int phylink_attach_phy(struct phylink *pl, struct phy_device *phy,
if (pl->phydev)
return -EBUSY;

- return phy_attach_direct(pl->netdev, phy, 0, interface);
+ return phy_attach_direct(pl->netdev, phy, phy->dev_flags, interface);
}

/**
diff --git a/include/linux/micrel_phy.h b/include/linux/micrel_phy.h
index ee23acc4d551..0117a2c126eb 100644
--- a/include/linux/micrel_phy.h
+++ b/include/linux/micrel_phy.h
@@ -39,6 +39,7 @@
/* struct phy_device dev_flags definitions */
#define MICREL_PHY_50MHZ_CLK 0x00000001
#define MICREL_PHY_FXEN 0x00000002
+#define MICREL_KSZ8_P1_ERRATA 0x00000003

#define MICREL_KSZ9021_EXTREG_CTRL 0xB
#define MICREL_KSZ9021_EXTREG_DATA_WRITE 0xC
diff --git a/net/dsa/slave.c b/net/dsa/slave.c
index 8c0f3c6ab365..7e208f16f006 100644
--- a/net/dsa/slave.c
+++ b/net/dsa/slave.c
@@ -1758,6 +1758,10 @@ static int dsa_slave_phy_connect(struct net_device *slave_dev, int addr)
return -ENODEV;
}

+ if (ds->ops->get_phy_flags)
+ slave_dev->phydev->dev_flags |=
+ ds->ops->get_phy_flags(ds, dp->index);
+
return phylink_connect_phy(dp->pl, slave_dev->phydev);
}

--
2.29.2