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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Florian Fainelli <f.fainelli@gmail.com>,
        "David S. Miller" <davem@davemloft.net>
Subject: [PATCH 4.9 37/71] net: dsa: bcm_sf2: Fix unbind ordering
Date:   Tue, 16 Oct 2018 19:09:34 +0200
Message-Id: <20181016170541.248439294@linuxfoundation.org>
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4.9-stable review patch.  If anyone has any objections, please let me know.

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

From: Florian Fainelli <f.fainelli@gmail.com>

[ 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@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 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
@@ -1129,10 +1129,10 @@ 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);
 	dsa_unregister_switch(priv->dev->ds);
+	/* Disable all ports and interrupts */
+	bcm_sf2_sw_suspend(priv->dev->ds);
 	bcm_sf2_mdio_unregister(priv);
 
 	return 0;