atl1: deal with hardware rx checksum bug (c2ac3ef3) · Commits · 戴 / test

The L1 hardware contains a bug that flags a fragmented IP packet as having an incorrect TCP/UDP checksum, even though the packet is perfectly valid and its checksum is correct. There's no way to distinguish between one of these good packets and a packet that actually contains a TCP/UDP checksum error, so all we can do is allow the packet to be handed up to the higher layers and let it be sorted out there. Add a comment describing this condition and remove the code that currently fails to handle what may or may not be a checksum error. Signed-off-by:

Jay Cliburn <jacliburn@bellsouth.net> Signed-off-by:

Jeff Garzik <jgarzik@redhat.com>

drivers/net/atlx/atl1.c

+11 −8

Original line number	Diff line number	Diff line
		@@ -1790,6 +1790,17 @@ static void atl1_rx_checksum(struct atl1_adapter *adapter,
		{
		struct pci_dev *pdev = adapter->pdev;

		/*
		* The L1 hardware contains a bug that erroneously sets the
		* PACKET_FLAG_ERR and ERR_FLAG_L4_CHKSUM bits whenever a
		* fragmented IP packet is received, even though the packet
		* is perfectly valid and its checksum is correct. There's
		* no way to distinguish between one of these good packets
		* and a packet that actually contains a TCP/UDP checksum
		* error, so all we can do is allow it to be handed up to
		* the higher layers and let it be sorted out there.
		*/

		skb->ip_summed = CHECKSUM_NONE;

		if (unlikely(rrd->pkt_flg & PACKET_FLAG_ERR)) {
		@@ -1816,14 +1827,6 @@ static void atl1_rx_checksum(struct atl1_adapter *adapter,
		return;
		}

		/* IPv4, but hardware thinks its checksum is wrong */
		if (netif_msg_rx_err(adapter))
		dev_printk(KERN_DEBUG, &pdev->dev,
		"hw csum wrong, pkt_flag:%x, err_flag:%x\n",
		rrd->pkt_flg, rrd->err_flg);
		skb->ip_summed = CHECKSUM_COMPLETE;
		skb->csum = htons(rrd->xsz.xsum_sz.rx_chksum);
		adapter->hw_csum_err++;
		return;
		}

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