Merge branch 'phy-micrel-toggling-reset'

Yoshihiro Shimoda says:

====================
net: phy: micrel: add toggling phy reset

This patch set is for R-Car Gen3 Salvator-XS boards. If we do
the following method, the phy cannot link up correctly.

1) Kernel boots by using initramfs.
--> No open the nic, so phy_device_register() and phy_probe()
deasserts the reset.
2) Kernel enters the suspend.
--> So, keep the reset signal as deassert.
--> On R-Car Salvator-XS board, unfortunately, the board power is
turned off.
3) Kernel returns from suspend.
4) ifconfig eth0 up
--> Then, since edge signal of the reset doesn't happen,
it cannot link up.
5) ifconfig eth0 down
6) ifconfig eth0 up
--> In this case, it can link up.

When resolving this issue after I got feedback from Andrew and Heiner,
I found an issue that the phy_device.c didn't call phy_resume()
if the PHY was not attached. So, patch 1 fixes it and add toggling
the phy reset to the micrel phy driver.

Changes from v1 (as RFC):
- No remove the current code of phy_device.c to avoid any side effects.
- Fix the mdio_bus_phy_resume() in phy_device.c.
- Add toggling the phy reset in micrel.c if the PHY is not attached.
====================

Signed-off-by: David S. Miller <[e-mail]>

drivers/net/phy/micrel.c

···
  *			 ksz9477
  */
 
+#include <linux/delay.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/phy.h>
···
 static int kszphy_resume(struct phy_device *phydev)
 {
 	int ret;
+
+	if (!phydev->attached_dev) {
+		/* If the PHY is not attached, toggle the reset */
+		phy_device_reset(phydev, 1);
+		udelay(1);
+		phy_device_reset(phydev, 0);
+	}
 
 	genphy_resume(phydev);
 

drivers/net/phy/phy_device.c

···
 static DEFINE_MUTEX(phy_fixup_lock);
 
 #ifdef CONFIG_PM
-static bool mdio_bus_phy_may_suspend(struct phy_device *phydev)
+static bool mdio_bus_phy_may_suspend(struct phy_device *phydev, bool suspend)
 {
 	struct device_driver *drv = phydev->mdio.dev.driver;
 	struct phy_driver *phydrv = to_phy_driver(drv);
···
 	/* PHY not attached? May suspend if the PHY has not already been
 	 * suspended as part of a prior call to phy_disconnect() ->
 	 * phy_detach() -> phy_suspend() because the parent netdev might be the
-	 * MDIO bus driver and clock gated at this point.
+	 * MDIO bus driver and clock gated at this point. Also may resume if
+	 * PHY is not attached.
 	 */
 	if (!netdev)
-		return !phydev->suspended;
+		return suspend ? !phydev->suspended : phydev->suspended;
 
 	if (netdev->wol_enabled)
 		return false;
···
 	if (phydev->attached_dev && phydev->adjust_link)
 		phy_stop_machine(phydev);
 
-	if (!mdio_bus_phy_may_suspend(phydev))
+	if (!mdio_bus_phy_may_suspend(phydev, true))
 		return 0;
 
 	return phy_suspend(phydev);
···
 	struct phy_device *phydev = to_phy_device(dev);
 	int ret;
 
-	if (!mdio_bus_phy_may_suspend(phydev))
+	if (!mdio_bus_phy_may_suspend(phydev, false))
 		goto no_resume;
 
 	ret = phy_resume(phydev);