summaryrefslogtreecommitdiff
path: root/drivers/net/pcs
diff options
context:
space:
mode:
authorVladimir Oltean <vladimir.oltean@nxp.com>2021-06-11 23:05:24 +0300
committerDavid S. Miller <davem@davemloft.net>2021-06-11 23:43:55 +0300
commit36641b045c839797739f9863e86e4dae2370e24f (patch)
tree41acc27c993b43cac0f7624d57450cd5927fe8df /drivers/net/pcs
parent2031c09e6d5f50d4c337da11efd1deb8279687d6 (diff)
downloadlinux-36641b045c839797739f9863e86e4dae2370e24f.tar.xz
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/pcs')
-rw-r--r--drivers/net/pcs/pcs-xpcs.c6
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 */