net: dsa: lantiq_gswip: fix order in .remove operation

Russell King pointed out that disabling the switch by clearing
GSWIP_MDIO_GLOB_ENABLE before calling dsa_unregister_switch() is
problematic, as it violates a Golden Rule of driver development to
always first unpublish userspace interfaces and then disable the
hardware.

Fix this, and also simplify the probe() function, by introducing a
dsa_switch_ops teardown() operation which takes care of clearing the
GSWIP_MDIO_GLOB_ENABLE bit.

Fixes: 14fceff4771e5 ("net: dsa: Add Lantiq / Intel DSA driver for vrx200")
Suggested-by: "Russell King (Oracle)" <linux@armlinux.org.uk>
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Link: https://patch.msgid.link/4ebd72a29edc1e4059b9666a26a0bb5d906a829a.1765241054.git.daniel@makrotopia.org
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/drivers/net/dsa/lantiq/lantiq_gswip.c b/drivers/net/dsa/lantiq/lantiq_gswip.c
index 57dd063c0740352865d1b5c14aad3beb8e53aafa..b094001a7c8057b6bf401bcaca92239c50178bbb 100644 (file)
--- a/drivers/net/dsa/lantiq/lantiq_gswip.c
+++ b/drivers/net/dsa/lantiq/lantiq_gswip.c
@@ -444,9 +444,6 @@ static void gswip_remove(struct platform_device *pdev)
        if (!priv)
                return;
 
-       /* disable the switch */
-       gswip_disable_switch(priv);
-
        dsa_unregister_switch(priv->ds);
 
        for (i = 0; i < priv->num_gphy_fw; i++)

diff --git a/drivers/net/dsa/lantiq/lantiq_gswip_common.c b/drivers/net/dsa/lantiq/lantiq_gswip_common.c
index 9da39edf8f57421690b7a11d5eee8cceb57e1282..6b171d58e18625ad1cc41fa12a373b221ad7aa95 100644 (file)
--- a/drivers/net/dsa/lantiq/lantiq_gswip_common.c
+++ b/drivers/net/dsa/lantiq/lantiq_gswip_common.c
@@ -752,6 +752,13 @@ static int gswip_setup(struct dsa_switch *ds)
        return 0;
 }
 
+static void gswip_teardown(struct dsa_switch *ds)
+{
+       struct gswip_priv *priv = ds->priv;
+
+       regmap_clear_bits(priv->mdio, GSWIP_MDIO_GLOB, GSWIP_MDIO_GLOB_ENABLE);
+}
+
 static enum dsa_tag_protocol gswip_get_tag_protocol(struct dsa_switch *ds,
                                                    int port,
                                                    enum dsa_tag_protocol mp)
@@ -1629,6 +1636,7 @@ static const struct phylink_mac_ops gswip_phylink_mac_ops = {
 static const struct dsa_switch_ops gswip_switch_ops = {
        .get_tag_protocol       = gswip_get_tag_protocol,
        .setup                  = gswip_setup,
+       .teardown               = gswip_teardown,
        .port_setup             = gswip_port_setup,
        .port_enable            = gswip_port_enable,
        .port_disable           = gswip_port_disable,
@@ -1718,15 +1726,14 @@ int gswip_probe_common(struct gswip_priv *priv, u32 version)
 
        err = gswip_validate_cpu_port(priv->ds);
        if (err)
-               goto disable_switch;
+               goto unregister_switch;
 
        dev_info(priv->dev, "probed GSWIP version %lx mod %lx\n",
                 GSWIP_VERSION_REV(version), GSWIP_VERSION_MOD(version));
 
        return 0;
 
-disable_switch:
-       gswip_disable_switch(priv);
+unregister_switch:
        dsa_unregister_switch(priv->ds);
 
        return err;