[PATCH net] net: dsa: microchip: set the correct number of ports

From: Codrin Ciubotariu
Date: Thu Jul 02 2020 - 05:45:29 EST


The number of ports is incorrectly set to the maximum available for a DSA
switch. Even if the extra ports are not used, this causes some functions
to be called later, like port_disable() and port_stp_state_set(). If the
driver doesn't check the port index, it will end up modifying unknown
registers.

Fixes: b987e98e50ab ("dsa: add DSA switch driver for Microchip KSZ9477")
Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@xxxxxxxxxxxxx>
---
drivers/net/dsa/microchip/ksz8795.c | 3 +++
drivers/net/dsa/microchip/ksz9477.c | 3 +++
2 files changed, 6 insertions(+)

diff --git a/drivers/net/dsa/microchip/ksz8795.c b/drivers/net/dsa/microchip/ksz8795.c
index 47d65b77caf7..7c17b0f705ec 100644
--- a/drivers/net/dsa/microchip/ksz8795.c
+++ b/drivers/net/dsa/microchip/ksz8795.c
@@ -1268,6 +1268,9 @@ static int ksz8795_switch_init(struct ksz_device *dev)
return -ENOMEM;
}

+ /* set the real number of ports */
+ dev->ds->num_ports = dev->port_cnt;
+
return 0;
}

diff --git a/drivers/net/dsa/microchip/ksz9477.c b/drivers/net/dsa/microchip/ksz9477.c
index 9a51b8a4de5d..8d15c3016024 100644
--- a/drivers/net/dsa/microchip/ksz9477.c
+++ b/drivers/net/dsa/microchip/ksz9477.c
@@ -1588,6 +1588,9 @@ static int ksz9477_switch_init(struct ksz_device *dev)
return -ENOMEM;
}

+ /* set the real number of ports */
+ dev->ds->num_ports = dev->port_cnt;
+
return 0;
}

--
2.25.1