This is a note to let you know that I've just added the patch titled
net: dsa: b53: fix max MTU for BCM5325/BCM5365
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-dsa-b53-fix-max-mtu-for-bcm5325-bcm5365.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 3bb9f6756d3f216b97bcb902f9c6b5cf3017e2e4
Author: Jonas Gorski <jonas.gorski@xxxxxxxxx>
Date: Fri Oct 4 10:47:19 2024 +0200
net: dsa: b53: fix max MTU for BCM5325/BCM5365
[ 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>
diff --git a/drivers/net/dsa/b53/b53_common.c b/drivers/net/dsa/b53/b53_common.c
index f7ae17ee6a32e..eea4d61a354cf 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)
@@ -2194,6 +2195,11 @@ 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;
}
