[PATCH 4.17 246/324] sfp: fix module initialisation with netdev already up

[Greg Kroah-Hartman]

4.17-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Russell King <rmk+kernel@xxxxxxxxxxxxxxx>

[ Upstream commit 576cd32082351620a4e76b8babc4d5ae9b4bbb98 ]

It was been observed that with a particular order of initialisation,
the netdev can be up, but the SFP module still has its TX_DISABLE
signal asserted.  This occurs when the network device brought up before
the SFP kernel module has been inserted by userspace.

This occurs because sfp-bus layer does not hear about the change in
network device state, and so assumes that it is still down.  Set
netdev->sfp when the upstream is registered to work around this problem.

Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/phy/sfp-bus.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/net/phy/sfp-bus.c
+++ b/drivers/net/phy/sfp-bus.c
@@ -349,7 +349,6 @@ static int sfp_register_bus(struct sfp_b
 	}
 	if (bus->started)
 		bus->socket_ops->start(bus->sfp);
-	bus->netdev->sfp_bus = bus;
 	bus->registered = true;
 	return 0;
 }
@@ -364,7 +363,6 @@ static void sfp_unregister_bus(struct sf
 		if (bus->phydev && ops && ops->disconnect_phy)
 			ops->disconnect_phy(bus->upstream);
 	}
-	bus->netdev->sfp_bus = NULL;
 	bus->registered = false;
 }
 
@@ -440,6 +438,7 @@ static void sfp_upstream_clear(struct sf
 {
 	bus->upstream_ops = NULL;
 	bus->upstream = NULL;
+	bus->netdev->sfp_bus = NULL;
 	bus->netdev = NULL;
 }
 
@@ -468,6 +467,7 @@ struct sfp_bus *sfp_register_upstream(st
 		bus->upstream_ops = ops;
 		bus->upstream = upstream;
 		bus->netdev = ndev;
+		ndev->sfp_bus = bus;
 
 		if (bus->sfp) {
 			ret = sfp_register_bus(bus);