Like the change made for mv88e6xxx, use mutex_lock_nested() to avoid
lockdep to give false positives because of nested MDIO busses.
The false positive was observed using a mv88e6060 from a TI816X SoC.
Signed-off-by: Neil Armstrong <narmstr...@baylibre.com>
---
drivers/net/dsa/mv88e6060.c | 19 +++++++++++++++++--
1 file changed, 17 insertions(+), 2 deletions(-)
diff --git a/drivers/net/dsa/mv88e6060.c b/drivers/net/dsa/mv88e6060.c
index c29aebe..b1db460 100644
--- a/drivers/net/dsa/mv88e6060.c
+++ b/drivers/net/dsa/mv88e6060.c
@@ -19,14 +19,24 @@
#define REG_PORT(p) (8 + (p))
#define REG_GLOBAL 0x0f
+/* MDIO bus access can be nested in the case of PHYs connected to the
+ * internal MDIO bus of the switch, which is accessed via MDIO bus of
+ * the Ethernet interface. Avoid lockdep false positives by using
+ * mutex_lock_nested().
+ */
static int reg_read(struct dsa_switch *ds, int addr, int reg)
{
+ int ret;
struct mii_bus *bus = dsa_host_dev_to_mii_bus(ds->master_dev);
if (bus == NULL)
return -EINVAL;
- return mdiobus_read(bus, ds->pd->sw_addr + addr, reg);
+ mutex_lock_nested(&bus->mdio_lock, SINGLE_DEPTH_NESTING);
+ ret = bus->read(bus, ds->pd->sw_addr, reg);
+ mutex_unlock(&bus->mdio_lock);
+
+ return ret;
}
#define REG_READ(addr, reg) \
@@ -42,12 +52,17 @@ static int reg_read(struct dsa_switch *ds, int addr, int
reg)
static int reg_write(struct dsa_switch *ds, int addr, int reg, u16 val)
{
+ int ret;
struct mii_bus *bus = dsa_host_dev_to_mii_bus(ds->master_dev);
if (bus == NULL)
return -EINVAL;
- return mdiobus_write(bus, ds->pd->sw_addr + addr, reg, val);
+ mutex_lock_nested(&bus->mdio_lock, SINGLE_DEPTH_NESTING);
+ ret = bus->write(bus, ds->pd->sw_addr, reg, val);
+ mutex_unlock(&bus->mdio_lock);
+
+ return ret;
}
#define REG_WRITE(addr, reg, val) \
--
1.9.1
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
