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authorNeil Armstrong <narmstrong@baylibre.com>2015-10-22 10:37:49 +0200
committerDavid S. Miller <davem@davemloft.net>2015-10-23 05:57:43 -0700
commit21dd19fed3c3eb42a3877600f4a97a774323e562 (patch)
tree54f25e3bd43a8ef81c0fd9fb5fc28cce8c1ad679 /drivers/net/phy/mdio_bus.c
parent6fb3b6b57ae444d7723088656dce86b1be92498d (diff)
downloadlinux-linaro-stable-21dd19fed3c3eb42a3877600f4a97a774323e562.tar.gz
net: phy: Add nested variants of mdiobus read/write
Since nested variants of mdiobus_read/write are used in multiple drivers, add nested variants in the mdiobus core. Suggested-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/phy/mdio_bus.c')
-rw-r--r--drivers/net/phy/mdio_bus.c55
1 files changed, 55 insertions, 0 deletions
diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index 12f44c53cc8e..88cb4592b6fb 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -372,6 +372,33 @@ struct phy_device *mdiobus_scan(struct mii_bus *bus, int addr)
EXPORT_SYMBOL(mdiobus_scan);
/**
+ * mdiobus_read_nested - Nested version of the mdiobus_read function
+ * @bus: the mii_bus struct
+ * @addr: the phy address
+ * @regnum: register number to read
+ *
+ * In case of nested MDIO bus access avoid lockdep false positives by
+ * using mutex_lock_nested().
+ *
+ * NOTE: MUST NOT be called from interrupt context,
+ * because the bus read/write functions may wait for an interrupt
+ * to conclude the operation.
+ */
+int mdiobus_read_nested(struct mii_bus *bus, int addr, u32 regnum)
+{
+ int retval;
+
+ BUG_ON(in_interrupt());
+
+ mutex_lock_nested(&bus->mdio_lock, SINGLE_DEPTH_NESTING);
+ retval = bus->read(bus, addr, regnum);
+ mutex_unlock(&bus->mdio_lock);
+
+ return retval;
+}
+EXPORT_SYMBOL(mdiobus_read_nested);
+
+/**
* mdiobus_read - Convenience function for reading a given MII mgmt register
* @bus: the mii_bus struct
* @addr: the phy address
@@ -396,6 +423,34 @@ int mdiobus_read(struct mii_bus *bus, int addr, u32 regnum)
EXPORT_SYMBOL(mdiobus_read);
/**
+ * mdiobus_write_nested - Nested version of the mdiobus_write function
+ * @bus: the mii_bus struct
+ * @addr: the phy address
+ * @regnum: register number to write
+ * @val: value to write to @regnum
+ *
+ * In case of nested MDIO bus access avoid lockdep false positives by
+ * using mutex_lock_nested().
+ *
+ * NOTE: MUST NOT be called from interrupt context,
+ * because the bus read/write functions may wait for an interrupt
+ * to conclude the operation.
+ */
+int mdiobus_write_nested(struct mii_bus *bus, int addr, u32 regnum, u16 val)
+{
+ int err;
+
+ BUG_ON(in_interrupt());
+
+ mutex_lock_nested(&bus->mdio_lock, SINGLE_DEPTH_NESTING);
+ err = bus->write(bus, addr, regnum, val);
+ mutex_unlock(&bus->mdio_lock);
+
+ return err;
+}
+EXPORT_SYMBOL(mdiobus_write_nested);
+
+/**
* mdiobus_write - Convenience function for writing a given MII mgmt register
* @bus: the mii_bus struct
* @addr: the phy address