This is a note to let you know that I've just added the patch titled
net: mdiobus: Set FWNODE_FLAG_NEEDS_CHILD_BOUND_ON_ADD for mdiobus parents
to the 5.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-mdiobus-set-fwnode_flag_needs_child_bound_on_add.patch
and it can be found in the queue-5.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 44a2a3669d5c4c69b0bbe8d029f1b3148f708ed2
Author: Saravana Kannan <saravanak@xxxxxxxxxx>
Date: Wed Sep 15 10:09:39 2021 -0700
net: mdiobus: Set FWNODE_FLAG_NEEDS_CHILD_BOUND_ON_ADD for mdiobus parents
[ Upstream commit 04f41c68f18886aea5afc68be945e7195ea1d598 ]
There are many instances of PHYs that depend on a switch to supply a
resource (Eg: interrupts). Switches also expects the PHYs to be probed
by their specific drivers as soon as they are added. If that doesn't
happen, then the switch would force the use of generic PHY drivers for
the PHY even if the PHY might have specific driver available.
fw_devlink=on by design can cause delayed probes of PHY. To avoid, this
we need to set the FWNODE_FLAG_NEEDS_CHILD_BOUND_ON_ADD for the switch's
fwnode before the PHYs are added. The most generic way to do this is to
set this flag for the parent of MDIO busses which is typically the
switch.
For more context:
https://lore.kernel.org/lkml/YTll0i6Rz3WAAYzs@xxxxxxx/#t
Fixes: ea718c699055 ("Revert "Revert "driver core: Set fw_devlink=on by default""")
Suggested-by: Andrew Lunn <andrew@xxxxxxx>
Signed-off-by: Saravana Kannan <saravanak@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20210915170940.617415-4-saravanak@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index 53f034fc2ef7..ee8313a4ac71 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -525,6 +525,10 @@ int __mdiobus_register(struct mii_bus *bus, struct module *owner)
NULL == bus->read || NULL == bus->write)
return -EINVAL;
+ if (bus->parent && bus->parent->of_node)
+ bus->parent->of_node->fwnode.flags |=
+ FWNODE_FLAG_NEEDS_CHILD_BOUND_ON_ADD;
+
BUG_ON(bus->state != MDIOBUS_ALLOCATED &&
bus->state != MDIOBUS_UNREGISTERED);
