Commit 55da1d7b authored Apr 24, 2022 by Jonathan Lemon Committed by Greg Kroah-Hartman May 12, 2022

net: bcmgenet: hide status block before TX timestamping



[ Upstream commit acac0541d1d65e81e599ec399d34d184d2424401 ]

The hardware checksum offloading requires use of a transmit
status block inserted before the outgoing frame data, this was
updated in '9a9ba2a4aaaa ("net: bcmgenet: always enable status blocks")'

However, skb_tx_timestamp() assumes that it is passed a raw frame
and PTP parsing chokes on this status block.

Fix this by calling __skb_pull(), which hides the TSB before calling
skb_tx_timestamp(), so an outgoing PTP packet is parsed correctly.

As the data in the skb has already been set up for DMA, and the
dma_unmap_* calls use a separately stored address, there is no
no effective change in the data transmission.

Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20220424165307.591145-1-jonathan.lemon@gmail.com


Fixes: d03825fb ("net: bcmgenet: add skb_tx_timestamp call")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent f495a90c

drivers/net/ethernet/broadcom/genet/bcmgenet.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -1549,6 +1549,11 @@ static struct sk_buff bcmgenet_put_tx_csum(struct net_device dev,
		return skb;
		}

		static void bcmgenet_hide_tsb(struct sk_buff *skb)
		{
		__skb_pull(skb, sizeof(struct status_64));
		}

		static netdev_tx_t bcmgenet_xmit(struct sk_buff skb, struct net_device dev)
		{
		struct bcmgenet_priv *priv = netdev_priv(dev);
		@@ -1657,6 +1662,8 @@ static netdev_tx_t bcmgenet_xmit(struct sk_buff skb, struct net_device dev)
		}

		GENET_CB(skb)->last_cb = tx_cb_ptr;

		bcmgenet_hide_tsb(skb);
		skb_tx_timestamp(skb);

		/* Decrement total BD count and advance our write pointer */