github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-11-07 06:17:02 +01:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

net: stmmac: disable TX checksum offload for jumbo frames on bugged cores

Browse Source 
stmmac_xdp_xmit_xdpf() decides TX checksum insertion from the queue COE
capability only:

	csum = !priv->plat->tx_queues_cfg[queue].coe_unsupported;

and lets the enhanced descriptor set TX_CIC_FULL accordingly. On the
bugged_jumbo cores (snps,dwmac-3.40a, snps,dwmac-3.610 and
snps,dwmac-3.710) hardware checksum insertion is broken for jumbo
frames; the skb path works around it by clearing NETIF_F_CSUM_MASK in
stmmac_fix_features() when the MTU exceeds ETH_DATA_LEN, so skbs are
never marked CHECKSUM_PARTIAL and no checksum is inserted. The XDP TX
path bypasses that workaround, so once XDP is allowed at MTU >
ETH_DATA_LEN, jumbo frames sent via XDP_TX or redirected into the
device would leave the interface with a full checksum insertion enabled
on those cores - exactly what the workaround is meant to avoid.

Disable checksum insertion for oversized frames on bugged_jumbo cores in
the XDP TX path too.

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@oss.qualcomm.com>
Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/20261012-stmmac-xdp-tx-pre-fixes-v1-2-05fd0c90f7e1@oss.qualcomm.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
This commit is contained in:
Lorenzo Bianconi 2026-10-12 17:24:40 +02:00 committed by Paolo Abeni
parent 2d5c08ec15
commit 667a375a52
1 changed files with 8 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
View File

@ -5278,6 +5278,14 @@ static int stmmac_xdp_xmit_xdpf(struct stmmac_priv *priv, int queue,
return STMMAC_XDP_CONSUMED;
}
/* Disable TX checksum offload for jumbo frames on cores where
* checksum insertion is broken for oversized frames, matching the
* stmmac_fix_features() workaround used by the skb path.
*/
if (priv->plat->bugged_jumbo &&
xdp_get_frame_len(xdpf) > ETH_FRAME_LEN)
csum = false;
while (true) {
skb_frag_t *frag = i ? &sinfo->frags[i - 1] : NULL;
int len = frag ? skb_frag_size(frag) : xdpf->len;