From 8c85f4b81296a530b8af2796c110fa482ac42d4f Mon Sep 17 00:00:00 2001 From: Yoshihiro Shimoda 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 Signed-off-by: Yoshihiro Shimoda Signed-off-by: David S. Miller --- 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 #include #include #include @@ -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