On 09/02/2019 20:34, Andrew Lunn wrote:
So we I see two possible solutions:
1) having both ds->slave_mii_bus and ds->ops->phy_read already defined is an
error, then it must be signaled to the calling code, or
I don't think we can do that. mv88e6xxx optionally instantiates the
MDIO busses, depending on what is in device tree. If there is no mdio
property, we need the DSA core to create an MDIO bus.
OK, but using the following check to know if DSA did such allocation is not
correct because DSA drivers can allocate it by their own:
static void dsa_switch_teardown(struct dsa_switch *ds)
{
if (ds->slave_mii_bus && ds->ops->phy_read)
mdiobus_unregister(ds->slave_mii_bus);
Maybe can we add a flag to register ds->slave_mii_bus allocation by DSA?
Looking at the driver, ds->slave_mii_bus is assigned in
mv88e6xxx_setup().
We have talked about adding a teardown() to the ops structure. This
seems like another argument we should do it. The mv88e6xxx_teardown()
can set ds->slave_mii_bus back to NULL, undoing what it did in the
setup code.
This seems reasonable to me, but in this case you have to call teardown()
operation before calling mdiobus_unregister() into dsa_switch_teardown() or we
still have the problem...
Ciao,
Rodolfo
--
GNU/Linux Solutions e-mail: giome...@enneenne.com
Linux Device Driver giome...@linux.it
Embedded Systems phone: +39 349 2432127
UNIX programming skype: rodolfo.giometti
