net: dsa: microchip: add error checking for ksz_pwrite

Add status validation for port register write inside
lan937x_change_mtu. ksz_pwrite and ksz_pread api's are
updated with return type int (Reference patch mentioned
below). Update lan937x_change_mtu with status validation
for ksz_pwrite16().

Link: https://patchwork.kernel.org/project/netdevbpf/patch/20220826105634.3855578-6-o.rempel@pengutronix.de/
Signed-off-by: Rakesh Sankaranarayanan <rakesh.sankaranarayanan@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/dsa/microchip/lan937x_main.c b/drivers/net/dsa/microchip/lan937x_main.c
index 7e4f307..06d3d03 100644 (file)
--- a/drivers/net/dsa/microchip/lan937x_main.c
+++ b/drivers/net/dsa/microchip/lan937x_main.c
@@ -242,7 +242,11 @@ int lan937x_change_mtu(struct ksz_device *dev, int port, int new_mtu)
        }
 
        /* Write the frame size in PORT_MAX_FR_SIZE register */
-       ksz_pwrite16(dev, port, PORT_MAX_FR_SIZE, new_mtu);
+       ret = ksz_pwrite16(dev, port, PORT_MAX_FR_SIZE, new_mtu);
+       if (ret) {
+               dev_err(ds->dev, "failed to update mtu for port %d\n", port);
+               return ret;
+       }
 
        return 0;
 }