[PATCH 4.14 028/109] net: dsa: bcm_sf2: Fix unbind ordering

From: Greg Kroah-Hartman
Date: Tue Oct 16 2018 - 13:18:08 EST

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


From: Florian Fainelli <f.fainelli@xxxxxxxxx>

[ Upstream commit bf3b452b7af787b8bf27de6490dc4eedf6f97599 ]

The order in which we release resources is unfortunately leading to bus
errors while dismantling the port. This is because we set
priv->wol_ports_mask to 0 to tell bcm_sf2_sw_suspend() that it is now
permissible to clock gate the switch. Later on, when dsa_slave_destroy()
comes in from dsa_unregister_switch() and calls
dsa_switch_ops::port_disable, we perform the same dismantling again, and
this time we hit registers that are clock gated.

Make sure that dsa_unregister_switch() is the first thing that happens,
which takes care of releasing all user visible resources, then proceed
with clock gating hardware. We still need to set priv->wol_ports_mask to
0 to make sure that an enabled port properly gets disabled in case it
was previously used as part of Wake-on-LAN.

Fixes: d9338023fb8e ("net: dsa: bcm_sf2: Make it a real platform device driver")
Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
drivers/net/dsa/bcm_sf2.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/net/dsa/bcm_sf2.c
+++ b/drivers/net/dsa/bcm_sf2.c
@@ -1264,10 +1264,10 @@ static int bcm_sf2_sw_remove(struct plat
struct bcm_sf2_priv *priv = platform_get_drvdata(pdev);

- /* Disable all ports and interrupts */
priv->wol_ports_mask = 0;
- bcm_sf2_sw_suspend(priv->dev->ds);
+ /* Disable all ports and interrupts */
+ bcm_sf2_sw_suspend(priv->dev->ds);

return 0;