From: Alexandre Belloni Date: Tue, 24 Apr 2018 16:09:04 +0000 (+0200) Subject: net: phy: allow scanning busses with missing phys X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=02a6efcab675fe32815d824837784c3f42a7d892;p=openwrt%2Fstaging%2Fblogic.git net: phy: allow scanning busses with missing phys Some MDIO busses will error out when trying to read a phy address with no phy present at that address. In that case, probing the bus will fail because __mdiobus_register() is scanning the bus for all possible phys addresses. In case MII_PHYSID1 returns -EIO or -ENODEV, consider there is no phy at this address and set the phy ID to 0xffffffff which is then properly handled in get_phy_device(). Suggested-by: Andrew Lunn Signed-off-by: Alexandre Belloni Reviewed-by: Florian Fainelli Signed-off-by: David S. Miller --- diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c index ac23322a32e1..9e4ba8e80a18 100644 --- a/drivers/net/phy/phy_device.c +++ b/drivers/net/phy/phy_device.c @@ -535,8 +535,17 @@ static int get_phy_id(struct mii_bus *bus, int addr, u32 *phy_id, /* Grab the bits from PHYIR1, and put them in the upper half */ phy_reg = mdiobus_read(bus, addr, MII_PHYSID1); - if (phy_reg < 0) + if (phy_reg < 0) { + /* if there is no device, return without an error so scanning + * the bus works properly + */ + if (phy_reg == -EIO || phy_reg == -ENODEV) { + *phy_id = 0xffffffff; + return 0; + } + return -EIO; + } *phy_id = (phy_reg & 0xffff) << 16;