From 8c85f4b81296a530b8af2796c110fa482ac42d4f Mon Sep 17 00:00:00 2001
From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Date: Wed, 28 Nov 2018 09:02:42 +0000
Subject: [PATCH] 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>
---
drivers/net/phy/micrel.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
index 9265dea79412..1679a6ea104c 100644
--- a/drivers/net/phy/micrel.c
+++ b/drivers/net/phy/micrel.c
@@ -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);
--
2.50.1