net: dsa: Fix cleanup resources upon module removal

[ Upstream commit 04761890 ]

The initial commit badly merged into the dsa_resume method instead
of the dsa_remove_dst method.
As consequence, the dst->master_netdev->dsa_ptr is not set to NULL on
removal and re-bind of the dsa device fails with error -17.

Fixes: b0dc635d ("net: dsa: cleanup resources upon module removal ")
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

net/dsa/dsa.c

@@ -935,6 +935,14 @@ static void dsa_remove_dst(struct dsa_switch_tree *dst)
 {
 	int i;
 
+	dst->master_netdev->dsa_ptr = NULL;
+
+	/* If we used a tagging format that doesn't have an ethertype
+	 * field, make sure that all packets from this point get sent
+	 * without the tag and go through the regular receive path.
+	 */
+	wmb();
+
 	for (i = 0; i < dst->pd->nr_chips; i++) {
 		struct dsa_switch *ds = dst->ds[i];
 
@@ -988,14 +996,6 @@ static int dsa_suspend(struct device *d)
 	struct dsa_switch_tree *dst = platform_get_drvdata(pdev);
 	int i, ret = 0;
 
-	dst->master_netdev->dsa_ptr = NULL;
-
-	/* If we used a tagging format that doesn't have an ethertype
-	 * field, make sure that all packets from this point get sent
-	 * without the tag and go through the regular receive path.
-	 */
-	wmb();
-
 	for (i = 0; i < dst->pd->nr_chips; i++) {
 		struct dsa_switch *ds = dst->ds[i];