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authorFlorian Fainelli <f.fainelli@gmail.com>2020-06-19 11:47:47 -0700
committerDavid S. Miller <davem@davemloft.net>2020-06-19 13:39:01 -0700
commitb2ffc75e2e990b09903f9d15ccd53bc5f3a4217c (patch)
treeb9c89e939d75d3feed38ea407fa6be77cc8de514 /drivers/net/phy
parent5a8d7f126c97d04d893f5e5be2b286437a0d01b0 (diff)
downloadlinux-b2ffc75e2e990b09903f9d15ccd53bc5f3a4217c.tar.bz2
net: phy: Check harder for errors in get_phy_id()
Commit 02a6efcab675 ("net: phy: allow scanning busses with missing phys") added a special condition to return -ENODEV in case -ENODEV or -EIO was returned from the first read of the MII_PHYSID1 register. In case the MDIO bus data line pull-up is not strong enough, the MDIO bus controller will not flag this as a read error. This can happen when a pluggable daughter card is not connected and weak internal pull-ups are used (since that is the only option, otherwise the pins are floating). The second read of MII_PHYSID2 will be correctly flagged an error though, but now we will return -EIO which will be treated as a hard error, thus preventing MDIO bus scanning loops to continue succesfully. Apply the same logic to both register reads, thus allowing the scanning logic to proceed. Fixes: 02a6efcab675 ("net: phy: allow scanning busses with missing phys") Reviewed-by: Andrew Lunn <andrew@lunn.ch> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/phy')
-rw-r--r--drivers/net/phy/phy_device.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 04946de74fa0..85ba95b598b5 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -794,8 +794,10 @@ static int get_phy_id(struct mii_bus *bus, int addr, u32 *phy_id,
/* Grab the bits from PHYIR2, and put them in the lower half */
phy_reg = mdiobus_read(bus, addr, MII_PHYSID2);
- if (phy_reg < 0)
- return -EIO;
+ if (phy_reg < 0) {
+ /* returning -ENODEV doesn't stop bus scanning */
+ return (phy_reg == -EIO || phy_reg == -ENODEV) ? -ENODEV : -EIO;
+ }
*phy_id |= phy_reg;