Commit 3b12e014 authored by Stephen Hemminger's avatar Stephen Hemminger Committed by Jeff Garzik
Browse files

sky2: sky2 FE+ receive status workaround 



The Yukon FE+ chip appears to have a hardware glitch that causes bogus
receive status values to be posted. The data in the packet is good, but
the status value is random garbage.  As a temporary workaround until the
problem is better understood, implement the workaround the vendor driver
used of ignoring the status value on this chip.

Since this means trusting dodgy hardware values; add additional checking
of the receive packet length.

Signed-off-by: default avatarStephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: default avatarJeff Garzik <jeff@garzik.org>
parent ff0ce684

drivers/net/sky2.c

+17 −11
Original line number Diff line number Diff line
@@ -2148,6 +2148,18 @@ static struct sk_buff *sky2_receive(struct net_device *dev, 
	sky2->rx_next = (sky2->rx_next + 1) % sky2->rx_pending;

	prefetch(sky2->rx_ring + sky2->rx_next);



	if (length < ETH_ZLEN || length > sky2->rx_data_size)

		goto len_error;



	/* This chip has hardware problems that generates bogus status.

	 * So do only marginal checking and expect higher level protocols

	 * to handle crap frames.

	 */

	if (sky2->hw->chip_id == CHIP_ID_YUKON_FE_P &&

	    sky2->hw->chip_rev == CHIP_REV_YU_FE2_A0 &&

	    length != count)

		goto okay;



	if (status & GMR_FS_ANY_ERR)

		goto error;
@@ -2156,8 +2168,9 @@ static struct sk_buff *sky2_receive(struct net_device *dev, 


	/* if length reported by DMA does not match PHY, packet was truncated */

	if (length != count)

		goto len_mismatch;

		goto len_error;



okay:

	if (length < copybreak)

		skb = receive_copy(sky2, re, length);

	else
@@ -2167,13 +2180,13 @@ resubmit: 


	return skb;



len_mismatch:

len_error:

	/* Truncation of overlength packets

	   causes PHY length to not match MAC length */

	++sky2->net_stats.rx_length_errors;

	if (netif_msg_rx_err(sky2) && net_ratelimit())

		pr_info(PFX "%s: rx length mismatch: length %d status %#x\n",

			dev->name, length, status);

		pr_info(PFX "%s: rx length error: status %#x length %d\n",

			dev->name, status, length);

	goto resubmit;



error:
@@ -3934,13 +3947,6 @@ static __devinit struct net_device *sky2_init_netdev(struct sky2_hw *hw, 
	sky2->hw = hw;

	sky2->msg_enable = netif_msg_init(debug, default_msg);



	/* This chip has hardware problems that generates

	 * bogus PHY receive status so by default shut up the message.

	 */

	if (hw->chip_id == CHIP_ID_YUKON_FE_P &&

	    hw->chip_rev == CHIP_REV_YU_FE2_A0)

		sky2->msg_enable &= ~NETIF_MSG_RX_ERR;



	/* Auto speed and flow control */

	sky2->autoneg = AUTONEG_ENABLE;

	sky2->flow_mode = FC_BOTH;

CRA Git | Maintained and supported by SUSTech CRA and CCSE