This is a note to let you know that I've just added the patch titled net: dsa: lantiq_gswip: fix maximum frame length to the 5.14-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-lantiq_gswip-fix-maximum-frame-length.patch and it can be found in the queue-5.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 552799f8b3b0074d2617f53a63a088f9514a66e3 Mon Sep 17 00:00:00 2001 From: Jan Hoffmann <jan@xxxxxx> Date: Wed, 1 Sep 2021 20:49:33 +0200 Subject: net: dsa: lantiq_gswip: fix maximum frame length From: Jan Hoffmann <jan@xxxxxx> commit 552799f8b3b0074d2617f53a63a088f9514a66e3 upstream. Currently, outgoing packets larger than 1496 bytes are dropped when tagged VLAN is used on a switch port. Add the frame check sequence length to the value of the register GSWIP_MAC_FLEN to fix this. This matches the lantiq_ppa vendor driver, which uses a value consisting of 1518 bytes for the MAC frame, plus the lengths of special tag and VLAN tags. Fixes: 14fceff4771e ("net: dsa: Add Lantiq / Intel DSA driver for vrx200") Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Jan Hoffmann <jan@xxxxxx> Acked-by: Hauke Mehrtens <hauke@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/dsa/lantiq_gswip.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/net/dsa/lantiq_gswip.c +++ b/drivers/net/dsa/lantiq_gswip.c @@ -843,7 +843,8 @@ static int gswip_setup(struct dsa_switch gswip_switch_mask(priv, 0, GSWIP_MAC_CTRL_2_MLEN, GSWIP_MAC_CTRL_2p(cpu_port)); - gswip_switch_w(priv, VLAN_ETH_FRAME_LEN + 8, GSWIP_MAC_FLEN); + gswip_switch_w(priv, VLAN_ETH_FRAME_LEN + 8 + ETH_FCS_LEN, + GSWIP_MAC_FLEN); gswip_switch_mask(priv, 0, GSWIP_BM_QUEUE_GCTRL_GL_MOD, GSWIP_BM_QUEUE_GCTRL); Patches currently in stable-queue which might be from jan@xxxxxx are queue-5.14/net-dsa-lantiq_gswip-fix-maximum-frame-length.patch