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| author | Vladimir Oltean <vladimir.oltean@nxp.com> | 2021-06-11 23:05:24 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2021-06-11 13:43:55 -0700 |
| commit | 36641b045c839797739f9863e86e4dae2370e24f (patch) | |
| tree | 41acc27c993b43cac0f7624d57450cd5927fe8df /drivers/net | |
| parent | 2031c09e6d5f50d4c337da11efd1deb8279687d6 (diff) | |
| download | linux-36641b045c839797739f9863e86e4dae2370e24f.tar.gz | |
net: pcs: xpcs: also ignore phy id if it's all ones
xpcs_get_id() searches multiple MMDs for a known PHY ID, starting with
MDIO_MMD_PCS (3). However not all integrators might have implemented
that MMD on their MDIO bus. For example, the NXP SJA1105 and SJA1110
switches only implement vendor-specific MMD 1 and 2.
When there is nothing on an MDIO bus at a certain address, traditionally
the bus returns 0xffff, which means that the bus remained in its default
pull-up state for the duration of the MDIO transaction. The 0xffff value
is widely used in drivers/net/phy/phy_device.c (see get_phy_c22_id for
example) to denote a missing device.
So it makes sense for the xpcs to ignore this value as well, and
continue its search, eventually finding the proper PHY ID in the
vendor-specific MMDs.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net')
| -rw-r--r-- | drivers/net/pcs/pcs-xpcs.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/net/pcs/pcs-xpcs.c b/drivers/net/pcs/pcs-xpcs.c index 743b53734eeb..ecf5011977d3 100644 --- a/drivers/net/pcs/pcs-xpcs.c +++ b/drivers/net/pcs/pcs-xpcs.c @@ -965,8 +965,10 @@ static u32 xpcs_get_id(struct dw_xpcs *xpcs) if (ret < 0) return 0xffffffff; - /* If Device IDs are not all zeros, we found C73 AN-type device */ - if (id | ret) + /* If Device IDs are not all zeros or all ones, + * we found C73 AN-type device + */ + if ((id | ret) && (id | ret) != 0xffffffff) return id | ret; /* Next, search C37 PCS using Vendor-Specific MII MMD */ |