sky2: be more selective about FIFO watchdog

Be more selective about when to enable the ram buffer watchdog code.
It is unnecessary on XL A3 or later revs, and with Yukon FE
the buffer is so small (4K) that the watchdog detects false positives.

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/net/sky2.c b/drivers/net/sky2.c
index f3a8243..0792031 100644
--- a/drivers/net/sky2.c
+++ b/drivers/net/sky2.c
@@ -826,7 +826,8 @@
 	sky2_write8(hw, SK_REG(port, TX_GMF_CTRL_T), GMF_RST_CLR);
 	sky2_write16(hw, SK_REG(port, TX_GMF_CTRL_T), GMF_OPER_ON);
 
-	if (!(hw->flags & SKY2_HW_RAMBUFFER)) {
+	/* On chips without ram buffer, pause is controled by MAC level */
+	if (sky2_read8(hw, B2_E_0) == 0) {
 		sky2_write8(hw, SK_REG(port, RX_GMF_LP_THR), 768/8);
 		sky2_write8(hw, SK_REG(port, RX_GMF_UP_THR), 1024/8);
 
@@ -1281,7 +1282,7 @@
 	struct sky2_port *sky2 = netdev_priv(dev);
 	struct sky2_hw *hw = sky2->hw;
 	unsigned port = sky2->port;
-	u32 imask;
+	u32 imask, ramsize;
 	int cap, err = -ENOMEM;
 	struct net_device *otherdev = hw->dev[sky2->port^1];
 
@@ -1336,13 +1337,12 @@
 
 	sky2_mac_init(hw, port);
 
-	if (hw->flags & SKY2_HW_RAMBUFFER) {
-		/* Register is number of 4K blocks on internal RAM buffer. */
-		u32 ramsize = sky2_read8(hw, B2_E_0) * 4;
+	/* Register is number of 4K blocks on internal RAM buffer. */
+	ramsize = sky2_read8(hw, B2_E_0) * 4;
+	if (ramsize > 0) {
 		u32 rxspace;
 
-		printk(KERN_DEBUG PFX "%s: ram buffer %dK\n", dev->name, ramsize);
-
+		pr_debug(PFX "%s: ram buffer %dK\n", dev->name, ramsize);
 		if (ramsize < 16)
 			rxspace = ramsize / 2;
 		else
@@ -2005,7 +2005,7 @@
 
 	synchronize_irq(hw->pdev->irq);
 
-	if (!(hw->flags & SKY2_HW_RAMBUFFER))
+	if (sky2_read8(hw, B2_E_0) == 0)
 		sky2_set_tx_stfwd(hw, port);
 
 	ctl = gma_read16(hw, port, GM_GP_CTRL);
@@ -2536,7 +2536,7 @@
 			++active;
 
 			/* For chips with Rx FIFO, check if stuck */
-			if ((hw->flags & SKY2_HW_RAMBUFFER) &&
+			if ((hw->flags & SKY2_HW_FIFO_HANG_CHECK) &&
 			     sky2_rx_hung(dev)) {
 				pr_info(PFX "%s: receiver hang detected\n",
 					dev->name);
@@ -2694,8 +2694,10 @@
 	switch(hw->chip_id) {
 	case CHIP_ID_YUKON_XL:
 		hw->flags = SKY2_HW_GIGABIT
-			| SKY2_HW_NEWER_PHY
-			| SKY2_HW_RAMBUFFER;
+			| SKY2_HW_NEWER_PHY;
+		if (hw->chip_rev < 3)
+			hw->flags |= SKY2_HW_FIFO_HANG_CHECK;
+
 		break;
 
 	case CHIP_ID_YUKON_EC_U:
@@ -2721,11 +2723,10 @@
 			dev_err(&hw->pdev->dev, "unsupported revision Yukon-EC rev A1\n");
 			return -EOPNOTSUPP;
 		}
-		hw->flags = SKY2_HW_GIGABIT | SKY2_HW_RAMBUFFER;
+		hw->flags = SKY2_HW_GIGABIT | SKY2_HW_FIFO_HANG_CHECK;
 		break;
 
 	case CHIP_ID_YUKON_FE:
-		hw->flags = SKY2_HW_RAMBUFFER;
 		break;
 
 	case CHIP_ID_YUKON_FE_P: