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author | Florian Fainelli <f.fainelli@gmail.com> | 2020-06-19 11:47:47 -0700 |
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committer | David S. Miller <davem@davemloft.net> | 2020-06-19 13:39:01 -0700 |
commit | b2ffc75e2e990b09903f9d15ccd53bc5f3a4217c (patch) | |
tree | b9c89e939d75d3feed38ea407fa6be77cc8de514 /drivers/net/phy | |
parent | 5a8d7f126c97d04d893f5e5be2b286437a0d01b0 (diff) | |
download | linux-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.c | 6 |
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; |