RE: [PATCH net-next 0/9] net: add phylink managed EEE support

On Fri, Jan 17, 2025 at 06:17:05PM +0800, Jiawen Wu wrote:

quoted

quoted

quoted

Since merging these patches, phylink_connect_phy() can no longer be
invoked correctly in ngbe_open(). The error is returned from the function
phy_eee_rx_clock_stop(). Since EEE is not supported on our NGBE hardware.

That would mean phy_modify_mmd() is failing, but the question is why
that is. Please investigate. Thanks.

Yes, phy_modify_mmd() returns -EOPNOTSUPP. Since .read/write_mmd are
implemented in the PHY driver, but it's not supported to read/write the
register field (devnum=MDIO_MMD_PCS, regnum= MDIO_CTRL1).

So the error occurs on  __phy_read_mmd():
	if (phydev->drv && phydev->drv->read_mmd)
		return phydev->drv->read_mmd(phydev, devad, regnum);

Thanks. The patch below should fix it. Please test, meanwhile I'll
prepare a proper patch.

diff --git a/drivers/net/phy/phylink.c b/drivers/net/phy/phylink.c
index 66eea3f963d3..56d411bb2547 100644
--- a/drivers/net/phy/phylink.c
+++ b/drivers/net/phy/phylink.c

@@ -2268,7 +2268,11 @@ static int phylink_bringup_phy(struct phylink *pl, struct phy_device *phy,
 	/* Explicitly configure whether the PHY is allowed to stop it's
 	 * receive clock.
 	 */
-	return phy_eee_rx_clock_stop(phy, pl->config->eee_rx_clk_stop_enable);
+	ret = phy_eee_rx_clock_stop(phy, pl->config->eee_rx_clk_stop_enable);
+	if (ret == -EOPNOTSUPP)
+		ret = 0;
+
+	return ret;
 }

 static int phylink_attach_phy(struct phylink *pl, struct phy_device *phy,