Commit 8c85f4b8 authored Nov 28, 2018 by Yoshihiro Shimoda Committed by David S. Miller Dec 03, 2018

net: phy: micrel: add toggling phy reset if PHY is not attached



This patch adds toggling phy reset if PHY is not attached. Otherwise,
some boards (e.g. R-Car H3 Salvator-XS) cannot link up correctly if
we do the following method:

 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.

Reported-by: Hiromitsu Yamasaki <hiromitsu.yamasaki.ym@renesas.com>
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent ef1b5bf5

drivers/net/phy/micrel.c

+8 −0

Original line number	Diff line number	Diff line
		@@ -23,6 +23,7 @@
		* ksz9477
		*/

		#include <linux/delay.h>
		#include <linux/kernel.h>
		#include <linux/module.h>
		#include <linux/phy.h>
		@@ -835,6 +836,13 @@ 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);

		ret = kszphy_config_reset(phydev);

Admin message