net: phy: broadcom: Save PHY counters during suspend

The PHY counters can be lost if the PHY is reset during suspend. We
need to save the values into the shadow counters or the accounting
will be incorrect over multiple suspend and resume cycles.

Fixes: 820ee17 ("net: phy: broadcom: Add support code for reading PHY counters")
Signed-off-by: Justin Chen <justin.chen@broadcom.com>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Link: https://patch.msgid.link/20260505173926.2870069-1-justin.chen@broadcom.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: Ryceancurry

drivers/net/phy/bcm-phy-lib.c

@@ -563,6 +563,15 @@ void bcm_phy_get_stats(struct phy_device *phydev, u64 *shadow,
 }
 EXPORT_SYMBOL_GPL(bcm_phy_get_stats);
 
+void bcm_phy_update_stats_shadow(struct phy_device *phydev, u64 *shadow)
+{
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(bcm_phy_hw_stats); i++)
+		bcm_phy_get_stat(phydev, shadow, i);
+}
+EXPORT_SYMBOL_GPL(bcm_phy_update_stats_shadow);
+
 void bcm_phy_r_rc_cal_reset(struct phy_device *phydev)
 {
 	/* Reset R_CAL/RC_CAL Engine */

drivers/net/phy/bcm-phy-lib.h

@@ -85,6 +85,7 @@ int bcm_phy_get_sset_count(struct phy_device *phydev);
 void bcm_phy_get_strings(struct phy_device *phydev, u8 *data);
 void bcm_phy_get_stats(struct phy_device *phydev, u64 *shadow,
 		       struct ethtool_stats *stats, u64 *data);
+void bcm_phy_update_stats_shadow(struct phy_device *phydev, u64 *shadow);
 void bcm_phy_r_rc_cal_reset(struct phy_device *phydev);
 int bcm_phy_28nm_a0b0_afe_config_init(struct phy_device *phydev);
 int bcm_phy_enable_jumbo(struct phy_device *phydev);

drivers/net/phy/bcm7xxx.c

@@ -807,6 +807,17 @@ static void bcm7xxx_28nm_get_phy_stats(struct phy_device *phydev,
 	bcm_phy_get_stats(phydev, priv->stats, stats, data);
 }
 
+static int bcm7xxx_28nm_suspend(struct phy_device *phydev)
+{
+	struct bcm7xxx_phy_priv *priv = phydev->priv;
+
+	mutex_lock(&phydev->lock);
+	bcm_phy_update_stats_shadow(phydev, priv->stats);
+	mutex_unlock(&phydev->lock);
+
+	return genphy_suspend(phydev);
+}
+
 static int bcm7xxx_28nm_probe(struct phy_device *phydev)
 {
 	struct bcm7xxx_phy_priv *priv;
@@ -849,6 +860,7 @@ static int bcm7xxx_28nm_probe(struct phy_device *phydev)
 	.flags		= PHY_IS_INTERNAL,				\
 	.config_init	= bcm7xxx_28nm_config_init,			\
 	.resume		= bcm7xxx_28nm_resume,				\
+	.suspend	= bcm7xxx_28nm_suspend,				\
 	.get_tunable	= bcm7xxx_28nm_get_tunable,			\
 	.set_tunable	= bcm7xxx_28nm_set_tunable,			\
 	.get_sset_count	= bcm_phy_get_sset_count,			\
@@ -866,6 +878,7 @@ static int bcm7xxx_28nm_probe(struct phy_device *phydev)
 	.flags		= PHY_IS_INTERNAL,				\
 	.config_init	= bcm7xxx_28nm_ephy_config_init,		\
 	.resume		= bcm7xxx_28nm_ephy_resume,			\
+	.suspend	= bcm7xxx_28nm_suspend,				\
 	.get_sset_count	= bcm_phy_get_sset_count,			\
 	.get_strings	= bcm_phy_get_strings,				\
 	.get_stats	= bcm7xxx_28nm_get_phy_stats,			\
@@ -902,6 +915,7 @@ static int bcm7xxx_28nm_probe(struct phy_device *phydev)
 	.config_aneg	= genphy_config_aneg,				\
 	.read_status	= genphy_read_status,				\
 	.resume		= bcm7xxx_16nm_ephy_resume,			\
+	.suspend	= bcm7xxx_28nm_suspend,				\
 }
 
 static struct phy_driver bcm7xxx_driver[] = {

drivers/net/phy/broadcom.c

@@ -592,8 +592,13 @@ static int bcm54xx_set_wakeup_irq(struct phy_device *phydev, bool state)
 
 static int bcm54xx_suspend(struct phy_device *phydev)
 {
+	struct bcm54xx_phy_priv *priv = phydev->priv;
 	int ret = 0;
 
+	mutex_lock(&phydev->lock);
+	bcm_phy_update_stats_shadow(phydev, priv->stats);
+	mutex_unlock(&phydev->lock);
+
 	bcm54xx_ptp_stop(phydev);
 
 	/* Acknowledge any Wake-on-LAN interrupt prior to suspend */