The ksz8795 and ksz9477 drivers differ in the way they count ports. For ksz8795, ksz_device::port_cnt does not include the host port whereas for ksz9477 it does. This inconsistency was fixed in Linux 5.11 by a series of changes, but remains in 5.10-stable. When probing, the common code treats a port device node with an address >= dev->port_cnt as a fatal error. As a minimal fix, change it to compare again dev->mib_port_cnt. This is the length of the dev->ports array that the port number will be used to index, and always includes the host port. Cc: Woojung Huh <woojung.huh@xxxxxxxxxxxxx> Cc: Microchip Linux Driver Support <UNGLinuxDriver@xxxxxxxxxxxxx> Cc: Michael Grzeschik <m.grzeschik@xxxxxxxxxxxxxx> Cc: Marek Vasut <marex@xxxxxxx> Signed-off-by: Ben Hutchings <ben.hutchings@xxxxxxx> --- drivers/net/dsa/microchip/ksz_common.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c index d4a64dbde315..88fa0779e0bc 100644 --- a/drivers/net/dsa/microchip/ksz_common.c +++ b/drivers/net/dsa/microchip/ksz_common.c @@ -432,7 +432,7 @@ int ksz_switch_register(struct ksz_device *dev, if (of_property_read_u32(port, "reg", &port_num)) continue; - if (port_num >= dev->port_cnt) + if (port_num >= dev->mib_port_cnt) return -EINVAL; of_get_phy_mode(port, &dev->ports[port_num].interface); -- 2.20.1
