[PATCH 5.15 018/107] net: smsc911x: Stop and start PHY during suspend and resume

[Greg Kroah-Hartman]

From: Florian Fainelli <f.fainelli@xxxxxxxxx>

[ Upstream commit 3ce9f2bef75528936c78a7053301f5725f622f3a ]

Commit 744d23c71af3 ("net: phy: Warn about incorrect
mdio_bus_phy_resume() state") unveiled that the smsc911x driver was not
properly stopping and restarting the PHY during suspend/resume. Correct
that by indicating that the MAC is in charge of PHY PM operations and
ensure that all MDIO bus activity is quiescent during suspend.

Tested-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Tested-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Fixes: fba863b81604 ("net: phy: make PHY PM ops a no-op if MAC driver manages PHY PM")
Fixes: 2aa70f864955 ("net: smsc911x: Quieten netif during suspend")
Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
Link: https://lore.kernel.org/r/20220825023951.3220-1-f.fainelli@xxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/net/ethernet/smsc/smsc911x.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/net/ethernet/smsc/smsc911x.c b/drivers/net/ethernet/smsc/smsc911x.c
index 592e191adbf7d..63b99dd8ca51c 100644
--- a/drivers/net/ethernet/smsc/smsc911x.c
+++ b/drivers/net/ethernet/smsc/smsc911x.c
@@ -1037,6 +1037,8 @@ static int smsc911x_mii_probe(struct net_device *dev)
 		return ret;
 	}
 
+	/* Indicate that the MAC is responsible for managing PHY PM */
+	phydev->mac_managed_pm = true;
 	phy_attached_info(phydev);
 
 	phy_set_max_speed(phydev, SPEED_100);
@@ -2584,6 +2586,8 @@ static int smsc911x_suspend(struct device *dev)
 	if (netif_running(ndev)) {
 		netif_stop_queue(ndev);
 		netif_device_detach(ndev);
+		if (!device_may_wakeup(dev))
+			phy_stop(ndev->phydev);
 	}
 
 	/* enable wake on LAN, energy detection and the external PME
@@ -2625,6 +2629,8 @@ static int smsc911x_resume(struct device *dev)
 	if (netif_running(ndev)) {
 		netif_device_attach(ndev);
 		netif_start_queue(ndev);
+		if (!device_may_wakeup(dev))
+			phy_start(ndev->phydev);
 	}
 
 	return 0;
-- 
2.35.1