The Renesas RZ/G3E SMARC EVK uses KSZ9131RNXC phy. On deep power state,
PHY loses the power and on wakeup the rgmii delays are not reconfigured
causing it to fail.

Replace the callback kszphy_resume()->ksz9131_resume() for reconfiguring
the rgmii_delay when it exits from PM suspend state.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
---
v1->v2:
 * Added ksz9131-specific phy_driver->resume to reconfigure the rgmii
   delays on exit from PM suspend state.
 * Replaced 'priv->is_suspended'->'phydev->suspended' for checking
   exit from PM state.
 * Updated commit description.
Ref:
 https://patchwork.kernel.org/project/linux-renesas-soc/patch/20250705170326.106073-1-biju.das.jz@bp.renesas.com/#26459627
---
 drivers/net/phy/micrel.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
index 74fd6ff32c6c..f678c1bdacdf 100644
--- a/drivers/net/phy/micrel.c
+++ b/drivers/net/phy/micrel.c
@@ -5633,6 +5633,14 @@ static int lan8841_suspend(struct phy_device *phydev)
 	return kszphy_generic_suspend(phydev);
 }
 
+static int ksz9131_resume(struct phy_device *phydev)
+{
+	if (phydev->suspended && phy_interface_is_rgmii(phydev))
+		ksz9131_config_rgmii_delay(phydev);
+
+	return kszphy_resume(phydev);
+}
+
 static struct phy_driver ksphy_driver[] = {
 {
 	.phy_id		= PHY_ID_KS8737,
@@ -5879,7 +5887,7 @@ static struct phy_driver ksphy_driver[] = {
 	.get_strings	= kszphy_get_strings,
 	.get_stats	= kszphy_get_stats,
 	.suspend	= kszphy_suspend,
-	.resume		= kszphy_resume,
+	.resume		= ksz9131_resume,
 	.cable_test_start	= ksz9x31_cable_test_start,
 	.cable_test_get_status	= ksz9x31_cable_test_get_status,
 	.get_features	= ksz9477_get_features,
-- 
2.43.0

On Fri, Jul 11, 2025 at 06:40:21AM +0100, Biju Das wrote:
> The Renesas RZ/G3E SMARC EVK uses KSZ9131RNXC phy. On deep power state,
> PHY loses the power and on wakeup the rgmii delays are not reconfigured
> causing it to fail.
> 
> Replace the callback kszphy_resume()->ksz9131_resume() for reconfiguring
> the rgmii_delay when it exits from PM suspend state.
> 
> Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>

Reviewed-by: Andrew Lunn <andrew@lunn.ch>

    Andrew