net: dpaa2-switch: disable the control interface on error path

Currently dpaa2_switch_takedown has a funny name and does not do the
opposite of dpaa2_switch_init, which makes probing fail when we need to
handle an -EPROBE_DEFER.

A sketch of what dpaa2_switch_init does:

	dpsw_open

	dpaa2_switch_detect_features

	dpsw_reset

	for (i = 0; i < ethsw->sw_attr.num_ifs; i++) {
		dpsw_if_disable

		dpsw_if_set_stp

		dpsw_vlan_remove_if_untagged

		dpsw_if_set_tci

		dpsw_vlan_remove_if
	}

	dpsw_vlan_remove

	alloc_ordered_workqueue

	dpsw_fdb_remove

	dpaa2_switch_ctrl_if_setup

When dpaa2_switch_takedown is called from the error path of
dpaa2_switch_probe(), the control interface, enabled by
dpaa2_switch_ctrl_if_setup from dpaa2_switch_init, remains enabled,
because dpaa2_switch_takedown does not call
dpaa2_switch_ctrl_if_teardown.

Since dpaa2_switch_probe might fail due to EPROBE_DEFER of a PHY, this
means that a second probe of the driver will happen with the control
interface directly enabled.

This will trigger a second error:

[   93.273528] fsl_dpaa2_switch dpsw.0: dpsw_ctrl_if_set_pools() failed
[   93.281966] fsl_dpaa2_switch dpsw.0: fsl_mc_driver_probe failed: -13
[   93.288323] fsl_dpaa2_switch: probe of dpsw.0 failed with error -13

Which if we investigate the /dev/dpaa2_mc_console log, we find out is
caused by:

[E, ctrl_if_set_pools:2211, DPMNG]  ctrl_if must be disabled

So make dpaa2_switch_takedown do the opposite of dpaa2_switch_init (in
reasonable limits, no reason to change STP state, re-add VLANs etc), and
rename it to something more conventional, like dpaa2_switch_teardown.

Fixes: 613c0a58 ("staging: dpaa2-switch: enable the control interface")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Link: https://lore.kernel.org/r/20210819141755.1931423-1-vladimir.oltean@nxp.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/freescale/dpaa2/dpaa2-switch.c

@@ -3038,26 +3038,30 @@ static int dpaa2_switch_port_init(struct ethsw_port_priv *port_priv, u16 port)
 	return err;
 }
 
-static void dpaa2_switch_takedown(struct fsl_mc_device *sw_dev)
+static void dpaa2_switch_ctrl_if_teardown(struct ethsw_core *ethsw)
+{
+	dpsw_ctrl_if_disable(ethsw->mc_io, 0, ethsw->dpsw_handle);
+	dpaa2_switch_free_dpio(ethsw);
+	dpaa2_switch_destroy_rings(ethsw);
+	dpaa2_switch_drain_bp(ethsw);
+	dpaa2_switch_free_dpbp(ethsw);
+}
+
+static void dpaa2_switch_teardown(struct fsl_mc_device *sw_dev)
 {
 	struct device *dev = &sw_dev->dev;
 	struct ethsw_core *ethsw = dev_get_drvdata(dev);
 	int err;
 
+	dpaa2_switch_ctrl_if_teardown(ethsw);
+
+	destroy_workqueue(ethsw->workqueue);
+
 	err = dpsw_close(ethsw->mc_io, 0, ethsw->dpsw_handle);
 	if (err)
 		dev_warn(dev, "dpsw_close err %d\n", err);
 }
 
-static void dpaa2_switch_ctrl_if_teardown(struct ethsw_core *ethsw)
-{
-	dpsw_ctrl_if_disable(ethsw->mc_io, 0, ethsw->dpsw_handle);
-	dpaa2_switch_free_dpio(ethsw);
-	dpaa2_switch_destroy_rings(ethsw);
-	dpaa2_switch_drain_bp(ethsw);
-	dpaa2_switch_free_dpbp(ethsw);
-}
-
 static int dpaa2_switch_remove(struct fsl_mc_device *sw_dev)
 {
 	struct ethsw_port_priv *port_priv;
@@ -3068,8 +3072,6 @@ static int dpaa2_switch_remove(struct fsl_mc_device *sw_dev)
 	dev = &sw_dev->dev;
 	ethsw = dev_get_drvdata(dev);
 
-	dpaa2_switch_ctrl_if_teardown(ethsw);
-
 	dpaa2_switch_teardown_irqs(sw_dev);
 
 	dpsw_disable(ethsw->mc_io, 0, ethsw->dpsw_handle);
@@ -3084,9 +3086,7 @@ static int dpaa2_switch_remove(struct fsl_mc_device *sw_dev)
 	kfree(ethsw->acls);
 	kfree(ethsw->ports);
 
-	dpaa2_switch_takedown(sw_dev);
-
-	destroy_workqueue(ethsw->workqueue);
+	dpaa2_switch_teardown(sw_dev);
 
 	fsl_mc_portal_free(ethsw->mc_io);
 
@@ -3199,7 +3199,7 @@ static int dpaa2_switch_probe(struct fsl_mc_device *sw_dev)
 			       GFP_KERNEL);
 	if (!(ethsw->ports)) {
 		err = -ENOMEM;
-		goto err_takedown;
+		goto err_teardown;
 	}
 
 	ethsw->fdbs = kcalloc(ethsw->sw_attr.num_ifs, sizeof(*ethsw->fdbs),
@@ -3270,8 +3270,8 @@ static int dpaa2_switch_probe(struct fsl_mc_device *sw_dev)
 err_free_ports:
 	kfree(ethsw->ports);
 
-err_takedown:
-	dpaa2_switch_takedown(sw_dev);
+err_teardown:
+	dpaa2_switch_teardown(sw_dev);
 
 err_free_cmdport:
 	fsl_mc_portal_free(ethsw->mc_io);