6.11-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jonas Gorski <jonas.gorski@xxxxxxxxx> [ Upstream commit ca8c1f71c10193c270f772d70d34b15ad765d6a8 ] BCM5325/BCM5365 do not support jumbo frames, so we should not report a jumbo frame mtu for them. But they do support so called "oversized" frames up to 1536 bytes long by default, so report an appropriate MTU. Fixes: 6ae5834b983a ("net: dsa: b53: add MTU configuration support") Signed-off-by: Jonas Gorski <jonas.gorski@xxxxxxxxx> Reviewed-by: Florian Fainelli <florian.fainelli@xxxxxxxxxxxx> Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/net/dsa/b53/b53_common.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/net/dsa/b53/b53_common.c b/drivers/net/dsa/b53/b53_common.c index 6fed3eb15ad9b..e8b20bfa8b83e 100644 --- a/drivers/net/dsa/b53/b53_common.c +++ b/drivers/net/dsa/b53/b53_common.c @@ -225,6 +225,7 @@ static const struct b53_mib_desc b53_mibs_58xx[] = { #define B53_MIBS_58XX_SIZE ARRAY_SIZE(b53_mibs_58xx) +#define B53_MAX_MTU_25 (1536 - ETH_HLEN - VLAN_HLEN - ETH_FCS_LEN) #define B53_MAX_MTU (9720 - ETH_HLEN - VLAN_HLEN - ETH_FCS_LEN) static int b53_do_vlan_op(struct b53_device *dev, u8 op) @@ -2270,6 +2271,11 @@ static int b53_change_mtu(struct dsa_switch *ds, int port, int mtu) static int b53_get_max_mtu(struct dsa_switch *ds, int port) { + struct b53_device *dev = ds->priv; + + if (is5325(dev) || is5365(dev)) + return B53_MAX_MTU_25; + return B53_MAX_MTU; } -- 2.43.0