diff options
| author | Andrew Lunn <andrew@lunn.ch> | 2016-04-11 21:40:05 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-04-12 03:15:48 +0200 |
| commit | 9a6f2b0113c8fce815db7c9d23754bdea4b428a0 (patch) | |
| tree | 05e5b4205fb6aebdcf105fa8866cfeceeec93ff9 /drivers/net/phy/mdio-mux.c | |
| parent | Merge branch 'rprpc-2nd-rewrite-part-1' (diff) | |
| download | linux-9a6f2b0113c8fce815db7c9d23754bdea4b428a0.tar.xz linux-9a6f2b0113c8fce815db7c9d23754bdea4b428a0.zip | |
net: mdio: Fix lockdep falls positive splat
MDIO devices can be stacked upon each other. The current code supports
two levels, which until recently has been enough for a DSA mdio bus on
top of another bus. Now we have hardware which has an MDIO mux in the
middle.
Define an MDIO MUTEX class with three levels.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/phy/mdio-mux.c')
| -rw-r--r-- | drivers/net/phy/mdio-mux.c | 10 |
1 files changed, 2 insertions, 8 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; |