Merge branch 'net-dsa-lantiq-a-bunch-of-fixes'

Daniel Golle says:

====================
net: dsa: lantiq: a bunch of fixes

This series is the continuation and result of comments received for a fix
for the SGMII restart-an bit not actually being self-clearing, which was
reported by by Rasmus Villemoes.

A closer investigation and testing the .remove and the .shutdown paths
of the mxl-gsw1xx.c and lantiq_gswip.c drivers has revealed a couple of
existing problems, which are also addressed in this series.
====================

Link: https://patch.msgid.link/cover.1765241054.git.daniel@makrotopia.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Author: Paolo Abeni

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++)

drivers/net/dsa/lantiq/lantiq_gswip.h

@@ -294,8 +294,6 @@ struct gswip_priv {
 	u16 version;
 };
 
-void gswip_disable_switch(struct gswip_priv *priv);
-
 int gswip_probe_common(struct gswip_priv *priv, u32 version);
 
 #endif /* __LANTIQ_GSWIP_H */

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,
@@ -1656,12 +1664,6 @@ static const struct dsa_switch_ops gswip_switch_ops = {
 	.port_hsr_leave		= dsa_port_simple_hsr_leave,
 };
 
-void gswip_disable_switch(struct gswip_priv *priv)
-{
-	regmap_clear_bits(priv->mdio, GSWIP_MDIO_GLOB, GSWIP_MDIO_GLOB_ENABLE);
-}
-EXPORT_SYMBOL_GPL(gswip_disable_switch);
-
 static int gswip_validate_cpu_port(struct dsa_switch *ds)
 {
 	struct gswip_priv *priv = ds->priv;
@@ -1718,15 +1720,14 @@ 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;

drivers/net/dsa/lantiq/mxl-gsw1xx.c

@@ -11,10 +11,12 @@
 
 #include <linux/bits.h>
 #include <linux/delay.h>
+#include <linux/jiffies.h>
 #include <linux/module.h>
 #include <linux/of_device.h>
 #include <linux/of_mdio.h>
 #include <linux/regmap.h>
+#include <linux/workqueue.h>
 #include <net/dsa.h>
 
 #include "lantiq_gswip.h"
@@ -29,6 +31,7 @@ struct gsw1xx_priv {
 	struct			regmap *clk;
 	struct			regmap *shell;
 	struct			phylink_pcs pcs;
+	struct delayed_work	clear_raneg;
 	phy_interface_t		tbi_interface;
 	struct gswip_priv	gswip;
 };
@@ -145,7 +148,9 @@ static void gsw1xx_pcs_disable(struct phylink_pcs *pcs)
 {
 	struct gsw1xx_priv *priv = pcs_to_gsw1xx(pcs);
 
-	/* Assert SGMII shell reset */
+	cancel_delayed_work_sync(&priv->clear_raneg);
+
+	/* Assert SGMII shell reset (will also clear RANEG bit) */
 	regmap_set_bits(priv->shell, GSW1XX_SHELL_RST_REQ,
 			GSW1XX_RST_REQ_SGMII_SHELL);
 
@@ -428,12 +433,29 @@ static int gsw1xx_pcs_config(struct phylink_pcs *pcs, unsigned int neg_mode,
 	return 0;
 }
 
+static void gsw1xx_pcs_clear_raneg(struct work_struct *work)
+{
+	struct gsw1xx_priv *priv =
+		container_of(work, struct gsw1xx_priv, clear_raneg.work);
+
+	regmap_clear_bits(priv->sgmii, GSW1XX_SGMII_TBI_ANEGCTL,
+			  GSW1XX_SGMII_TBI_ANEGCTL_RANEG);
+}
+
 static void gsw1xx_pcs_an_restart(struct phylink_pcs *pcs)
 {
 	struct gsw1xx_priv *priv = pcs_to_gsw1xx(pcs);
 
+	cancel_delayed_work_sync(&priv->clear_raneg);
+
 	regmap_set_bits(priv->sgmii, GSW1XX_SGMII_TBI_ANEGCTL,
 			GSW1XX_SGMII_TBI_ANEGCTL_RANEG);
+
+	/* despite being documented as self-clearing, the RANEG bit
+	 * sometimes remains set, preventing auto-negotiation from happening.
+	 * MaxLinear advises to manually clear the bit after 10ms.
+	 */
+	schedule_delayed_work(&priv->clear_raneg, msecs_to_jiffies(10));
 }
 
 static void gsw1xx_pcs_link_up(struct phylink_pcs *pcs,
@@ -636,6 +658,8 @@ static int gsw1xx_probe(struct mdio_device *mdiodev)
 	if (ret)
 		return ret;
 
+	INIT_DELAYED_WORK(&priv->clear_raneg, gsw1xx_pcs_clear_raneg);
+
 	ret = gswip_probe_common(&priv->gswip, version);
 	if (ret)
 		return ret;
@@ -648,25 +672,31 @@ static int gsw1xx_probe(struct mdio_device *mdiodev)
 static void gsw1xx_remove(struct mdio_device *mdiodev)
 {
 	struct gswip_priv *priv = dev_get_drvdata(&mdiodev->dev);
+	struct gsw1xx_priv *gsw1xx_priv;
 
 	if (!priv)
 		return;
 
-	gswip_disable_switch(priv);
-
 	dsa_unregister_switch(priv->ds);
+
+	gsw1xx_priv = container_of(priv, struct gsw1xx_priv, gswip);
+	cancel_delayed_work_sync(&gsw1xx_priv->clear_raneg);
 }
 
 static void gsw1xx_shutdown(struct mdio_device *mdiodev)
 {
 	struct gswip_priv *priv = dev_get_drvdata(&mdiodev->dev);
+	struct gsw1xx_priv *gsw1xx_priv;
 
 	if (!priv)
 		return;
 
+	dsa_switch_shutdown(priv->ds);
+
 	dev_set_drvdata(&mdiodev->dev, NULL);
 
-	gswip_disable_switch(priv);
+	gsw1xx_priv = container_of(priv, struct gsw1xx_priv, gswip);
+	cancel_delayed_work_sync(&gsw1xx_priv->clear_raneg);
 }
 
 static const struct gswip_hw_info gsw12x_data = {