Commit 68c8fdb9 authored Dec 28, 2023 by Adrian Cinal Committed by Greg Kroah-Hartman Jan 15, 2024

net: bcmgenet: Fix FCS generation for fragmented skbuffs



[ Upstream commit e584f2ff1e6cc9b1d99e8a6b0f3415940d1b3eb3 ]

The flag DMA_TX_APPEND_CRC was only written to the first DMA descriptor
in the TX path, where each descriptor corresponds to a single skbuff
fragment (or the skbuff head). This led to packets with no FCS appearing
on the wire if the kernel allocated the packet in fragments, which would
always happen when using PACKET_MMAP/TPACKET (cf. tpacket_fill_skb() in
net/af_packet.c).

Fixes: 1c1008c7 ("net: bcmgenet: add main driver file")
Signed-off-by: Adrian Cinal <adriancinal1@gmail.com>
Acked-by: Doug Berger <opendmb@gmail.com>
Acked-by: Florian Fainelli <florian.fainelli@broadcom.com>
Link: https://lore.kernel.org/r/20231228135638.1339245-1-adriancinal1@gmail.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent 4c0fa624

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

+3 −1

Original line number	Diff line number	Diff line
		@@ -1648,8 +1648,10 @@ static netdev_tx_t bcmgenet_xmit(struct sk_buff skb, struct net_device dev)
		/* Note: if we ever change from DMA_TX_APPEND_CRC below we
		* will need to restore software padding of "runt" packets
		*/
		len_stat \|= DMA_TX_APPEND_CRC;

		if (!i) {
		len_stat \|= DMA_TX_APPEND_CRC \| DMA_SOP;
		len_stat \|= DMA_SOP;
		if (skb->ip_summed == CHECKSUM_PARTIAL)
		len_stat \|= DMA_TX_DO_CSUM;
		}