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path: root/drivers/net/phy/mdio-mux.c
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* net: mdio: Fix lockdep falls positive splatAndrew Lunn2016-04-111-8/+2
| | | | | | | | | | | | 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>
* mdio: Move allocation of interrupts into coreAndrew Lunn2016-01-071-2/+1
| | | | | | | | | | Have mdio_alloc() create the array of interrupt numbers, and initialize it to POLLING. This is what most MDIO drivers want, so allowing code to be removed from the drivers. Signed-off-by: Andrew Lunn <andrew@lunn.ch> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: phy: mdio-mux: Check return value of mdiobus_alloc()Tobias Klauser2015-12-141-1/+6
| | | | | | | | | | mdiobus_alloc() might return NULL, but its return value is not checked in mdio_mux_init(). This could potentially lead to a NULL pointer dereference. Fix it by checking the return value Fixes: 0ca2997d1452 ("netdev/of/phy: Add MDIO bus multiplexer support.") Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
* netdev/phy: add missing of_node_putJulia Lawall2015-10-261-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | for_each_available_child_of_node performs an of_node_get on each iteration, so a break out of the loop requires an of_node_put. A simplified version of the semantic patch that fixes this problem is as follows (http://coccinelle.lip6.fr): // <smpl> @@ local idexpression r.n; expression r,e; @@ for_each_available_child_of_node(r,n) { ... ( of_node_put(n); | e = n | + of_node_put(n); ? break; ) ... } ... when != n // </smpl> Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> Signed-off-by: David S. Miller <davem@davemloft.net>
* phy: fix of_mdio_find_bus() device refcount leakRussell King2015-09-241-6/+13
| | | | | | | | | | | | | | | | | | | | of_mdio_find_bus() leaks a struct device refcount, caused by using class_find_device() and not realising that the device reference has its refcount incremented: * Note, you will need to drop the reference with put_device() after use. ... while ((dev = class_dev_iter_next(&iter))) { if (match(dev, data)) { get_device(dev); break; } Update the comment, and arrange for the phy code to drop this refcount when disposing of a reference to it. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
* netdev/phy: skip disabled mdio-mux nodesTimur Tabi2012-08-201-1/+1
| | | | | | | | | | | The mdio-mux driver scans all child mdio nodes, without regard to whether the node is actually used. Some device trees include all possible mdio-mux nodes and rely on the boot loader to disable those that are not present, based on some run-time configuration. Those nodes need to be skipped. Signed-off-by: Timur Tabi <timur@freescale.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* netdev/phy: Fixup lockdep warnings in mdio-mux.cDavid Daney2012-07-091-2/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With lockdep enabled we get: ============================================= [ INFO: possible recursive locking detected ] 3.4.4-Cavium-Octeon+ #313 Not tainted --------------------------------------------- kworker/u:1/36 is trying to acquire lock: (&bus->mdio_lock){+.+...}, at: [<ffffffff813da7e8>] mdio_mux_read+0x38/0xa0 but task is already holding lock: (&bus->mdio_lock){+.+...}, at: [<ffffffff813d79e4>] mdiobus_read+0x44/0x88 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&bus->mdio_lock); lock(&bus->mdio_lock); *** DEADLOCK *** May be due to missing lock nesting notation . . . This is a false positive, since we are indeed using 'nested' locking, we need to use mutex_lock_nested(). Now in theory we can stack multiple MDIO multiplexers, but that would require passing the nesting level (which is difficult to know) to mutex_lock_nested(). Instead we assume the simple case of a single level of nesting. Since these are only warning messages, it isn't so important to solve the general case. Signed-off-by: David Daney <david.daney@cavium.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* netdev/of/phy: Add MDIO bus multiplexer support.David Daney2012-05-071-0/+192
This patch adds a somewhat generic framework for MDIO bus multiplexers. It is modeled on the I2C multiplexer. The multiplexer is needed if there are multiple PHYs with the same address connected to the same MDIO bus adepter, or if there is insufficient electrical drive capability for all the connected PHY devices. Conceptually it could look something like this: ------------------ | Control Signal | --------+--------- | --------------- --------+------ | MDIO MASTER |---| Multiplexer | --------------- --+-------+---- | | C C h h i i l l d d | | --------- A B --------- | | | | | | | PHY@1 +-------+ +---+ PHY@1 | | | | | | | --------- | | --------- --------- | | --------- | | | | | | | PHY@2 +-------+ +---+ PHY@2 | | | | | --------- --------- This framework configures the bus topology from device tree data. The mechanics of switching the multiplexer is left to device specific drivers. The follow-on patch contains a multiplexer driven by GPIO lines. Signed-off-by: David Daney <david.daney@cavium.com> Signed-off-by: David S. Miller <davem@davemloft.net>