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-rw-r--r--drivers/net/phy/mdio_bus.c37
-rw-r--r--include/linux/micrel_phy.h2
2 files changed, 36 insertions, 3 deletions
diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index 667247f661c5..a664eeb1868d 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -19,6 +19,7 @@
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
+#include <linux/micrel_phy.h>
#include <linux/mii.h>
#include <linux/mm.h>
#include <linux/module.h>
@@ -600,6 +601,32 @@ static int mdiobus_scan_bus_c45(struct mii_bus *bus)
return 0;
}
+/* There are some C22 PHYs which do bad things when where is a C45
+ * transaction on the bus, like accepting a read themselves, and
+ * stomping over the true devices reply, to performing a write to
+ * themselves which was intended for another device. Now that C22
+ * devices have been found, see if any of them are bad for C45, and if we
+ * should skip the C45 scan.
+ */
+static bool mdiobus_prevent_c45_scan(struct mii_bus *bus)
+{
+ int i;
+
+ for (i = 0; i < PHY_MAX_ADDR; i++) {
+ struct phy_device *phydev;
+ u32 oui;
+
+ phydev = mdiobus_get_phy(bus, i);
+ if (!phydev)
+ continue;
+ oui = phydev->phy_id >> 10;
+
+ if (oui == MICREL_OUI)
+ return true;
+ }
+ return false;
+}
+
/**
* __mdiobus_register - bring up all the PHYs on a given bus and attach them to bus
* @bus: target mii_bus
@@ -617,8 +644,9 @@ static int mdiobus_scan_bus_c45(struct mii_bus *bus)
int __mdiobus_register(struct mii_bus *bus, struct module *owner)
{
struct mdio_device *mdiodev;
- int i, err;
struct gpio_desc *gpiod;
+ bool prevent_c45_scan;
+ int i, err;
if (!bus || !bus->name)
return -EINVAL;
@@ -691,8 +719,11 @@ int __mdiobus_register(struct mii_bus *bus, struct module *owner)
goto error;
}
- if (bus->probe_capabilities == MDIOBUS_C45 ||
- bus->probe_capabilities == MDIOBUS_C22_C45) {
+ prevent_c45_scan = mdiobus_prevent_c45_scan(bus);
+
+ if (!prevent_c45_scan &&
+ (bus->probe_capabilities == MDIOBUS_C45 ||
+ bus->probe_capabilities == MDIOBUS_C22_C45)) {
err = mdiobus_scan_bus_c45(bus);
if (err)
goto error;
diff --git a/include/linux/micrel_phy.h b/include/linux/micrel_phy.h
index 1f7c33b2f5a3..771e050883db 100644
--- a/include/linux/micrel_phy.h
+++ b/include/linux/micrel_phy.h
@@ -8,6 +8,8 @@
#ifndef _MICREL_PHY_H
#define _MICREL_PHY_H
+#define MICREL_OUI 0x0885
+
#define MICREL_PHY_ID_MASK 0x00fffff0
#define PHY_ID_KSZ8873MLL 0x000e7237