Sebastian,

On Wed, May 29, 2013 at 09:32:43PM +0200, Sebastian Hesselbarth wrote:

Using a separated mdio bus driver with mvmdio, phy_detach on network device
removal will not stop the phy and finally lead to NULL pointer dereference
in mvmdio due to non-existent network device. Use phy_disconnect instead
to properly stop phy device from accessing network device prior removal of
the network device.

Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
---
Note: I observed this behavior when removing a modular mv643xx_eth driver
after attaching it to a phy handled by (also modular) mvmdio. The mvmdio
conversion has been done in

commit c3a07134e6aa5b93a37f72ffa3d11fadf72bf757
 ("mv643xx_eth: convert to use the Marvell Orion MDIO driver")

and should go back any -stable version with that commit (propably only 3.9)

It looks like just v3.10-rcX, here.

thx,

Jason.