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authorAlexandre Belloni <alexandre.belloni@bootlin.com>2018-04-24 19:09:04 +0300
committerDavid S. Miller <davem@davemloft.net>2018-04-25 19:59:42 +0300
commit02a6efcab675fe32815d824837784c3f42a7d892 (patch)
treeee3c114159c833e170a405be27cf86b44b34396c /drivers
parent3be4aaf4e2d3eb95cce7835e8df797ae65ae5ac1 (diff)
downloadlinux-02a6efcab675fe32815d824837784c3f42a7d892.tar.xz
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 <andrew@lunn.ch> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/net/phy/phy_device.c11
1 files changed, 10 insertions, 1 deletions
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;