Subject: [PATCH 2/2] sky2: dual-port pci-x checksum fix

From: Stephen Hemminger <[email-masked]>
Date: Wed, 21 Feb 2007 16:04:43 -0800

Add a workaround for dual port PCI-X card that returns status out of
order sometimes because of split transactions.

Signed-off-by: Stephen Hemminger <[email-masked]>

--- linux-2.6.16.40.orig/drivers/net/sky2.c	2007-02-14 16:45:23.000000000 -0800
+++ linux-2.6.16.40/drivers/net/sky2.c	2007-02-14 16:47:06.000000000 -0800
@@ -1031,7 +1031,25 @@
 	struct sky2_hw *hw = sky2->hw;
 	unsigned port = sky2->port;
 	u32 ramsize, rxspace;
-	int err = -ENOMEM;
+	int cap, err = -ENOMEM;
+	struct net_device *otherdev = hw->dev[sky2->port^1];
+
+	/*
+ 	 * On dual port PCI-X card, there is an problem where status
+	 * can be received out of order due to split transactions
+	 */
+	if (otherdev && netif_running(otherdev) &&
+ 	    (cap = pci_find_capability(hw->pdev, PCI_CAP_ID_PCIX))) {
+ 		struct sky2_port *osky2 = netdev_priv(otherdev);
+ 		u16 cmd;
+
+ 		cmd = sky2_pci_read16(hw, cap + PCI_X_CMD);
+ 		cmd &= ~PCI_X_CMD_MAX_SPLIT;
+ 		sky2_pci_write16(hw, cap + PCI_X_CMD, cmd);
+
+ 		sky2->rx_csum = 0;
+ 		osky2->rx_csum = 0;
+ 	}
 
 	if (netif_msg_ifup(sky2))
 		printk(KERN_INFO PFX "%s: enabling interface\n", dev->name);

--
Stephen Hemminger <[email-masked]>