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-rw-r--r--drivers/net/phy/mdio-mux.c10
-rw-r--r--drivers/net/phy/mdio_bus.c4
-rw-r--r--include/linux/mdio.h11
3 files changed, 15 insertions, 10 deletions
diff --git a/drivers/net/phy/mdio-mux.c b/drivers/net/phy/mdio-mux.c
index 308ade0eb1b6..5c81d6faf304 100644
--- a/drivers/net/phy/mdio-mux.c
+++ b/drivers/net/phy/mdio-mux.c
@@ -45,13 +45,7 @@ static int mdio_mux_read(struct mii_bus *bus, int phy_id, int regnum)
struct mdio_mux_parent_bus *pb = cb->parent;
int r;
- /* In theory multiple mdio_mux could be stacked, thus creating
- * more than a single level of nesting. But in practice,
- * SINGLE_DEPTH_NESTING will cover the vast majority of use
- * cases. We use it, instead of trying to handle the general
- * case.
- */
- mutex_lock_nested(&pb->mii_bus->mdio_lock, SINGLE_DEPTH_NESTING);
+ mutex_lock_nested(&pb->mii_bus->mdio_lock, MDIO_MUTEX_MUX);
r = pb->switch_fn(pb->current_child, cb->bus_number, pb->switch_data);
if (r)
goto out;
@@ -76,7 +70,7 @@ static int mdio_mux_write(struct mii_bus *bus, int phy_id,
int r;
- mutex_lock_nested(&pb->mii_bus->mdio_lock, SINGLE_DEPTH_NESTING);
+ mutex_lock_nested(&pb->mii_bus->mdio_lock, MDIO_MUTEX_MUX);
r = pb->switch_fn(pb->current_child, cb->bus_number, pb->switch_data);
if (r)
goto out;
diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index 0cba64f1ecf4..751202a285a6 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -457,7 +457,7 @@ int mdiobus_read_nested(struct mii_bus *bus, int addr, u32 regnum)
BUG_ON(in_interrupt());
- mutex_lock_nested(&bus->mdio_lock, SINGLE_DEPTH_NESTING);
+ mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
retval = bus->read(bus, addr, regnum);
mutex_unlock(&bus->mdio_lock);
@@ -509,7 +509,7 @@ int mdiobus_write_nested(struct mii_bus *bus, int addr, u32 regnum, u16 val)
BUG_ON(in_interrupt());
- mutex_lock_nested(&bus->mdio_lock, SINGLE_DEPTH_NESTING);
+ mutex_lock_nested(&bus->mdio_lock, MDIO_MUTEX_NESTED);
err = bus->write(bus, addr, regnum, val);
mutex_unlock(&bus->mdio_lock);
diff --git a/include/linux/mdio.h b/include/linux/mdio.h
index 5bfd99d1a40a..bf9d1d750693 100644
--- a/include/linux/mdio.h
+++ b/include/linux/mdio.h
@@ -13,6 +13,17 @@
struct mii_bus;
+/* Multiple levels of nesting are possible. However typically this is
+ * limited to nested DSA like layer, a MUX layer, and the normal
+ * user. Instead of trying to handle the general case, just define
+ * these cases.
+ */
+enum mdio_mutex_lock_class {
+ MDIO_MUTEX_NORMAL,
+ MDIO_MUTEX_MUX,
+ MDIO_MUTEX_NESTED,
+};
+
struct mdio_device {
struct device dev;