From: Neil Horman <nhorman@redhat.com>
Subject: [RHEL5 PATCH]: b44: phy reset problem that leads to link flap under moderate traffic
Date: Tue, 2 Jan 2007 13:17:53 -0500
Bugzilla: 216338
Message-Id: <20070102181753.GA16938@hmsendeavour.rdu.redhat.com>
Changelog: net: b44: phy reset problem that leads to link flap 


hey all-
	Patch to correct phy reset logic in the b44 driver.  This patch is a
backport of the upstream patch currently being proposed by broadcom to fix
these phy resets and the resultant link flap that moderate traffic can cause.
fixes bz 216338.

Thanks & Regards
Neil


--- linux-2.6.18.noarch/drivers/net/b44.c.orig	2007-01-02 08:59:09.000000000 -0500
+++ linux-2.6.18.noarch/drivers/net/b44.c	2007-01-02 10:55:28.000000000 -0500
@@ -111,6 +111,11 @@ MODULE_DEVICE_TABLE(pci, b44_pci_tbl);
 
 static void b44_halt(struct b44 *);
 static void b44_init_rings(struct b44 *);
+
+#define B44_FULL_RESET		1
+#define B44_FULL_RESET_SKIP_PHY	2
+#define B44_PARTIAL_RESET	3
+
 static void b44_init_hw(struct b44 *, int);
 
 static int dma_desc_align_mask;
@@ -883,7 +888,7 @@ static int b44_poll(struct net_device *n
 		spin_lock_irq(&bp->lock);
 		b44_halt(bp);
 		b44_init_rings(bp);
-		b44_init_hw(bp, 1);
+		b44_init_hw(bp, B44_FULL_RESET_SKIP_PHY);
 		netif_wake_queue(bp->dev);
 		spin_unlock_irq(&bp->lock);
 		done = 1;
@@ -952,7 +957,7 @@ static void b44_tx_timeout(struct net_de
 
 	b44_halt(bp);
 	b44_init_rings(bp);
-	b44_init_hw(bp, 1);
+	b44_init_hw(bp, B44_FULL_RESET);
 
 	spin_unlock_irq(&bp->lock);
 
@@ -1069,7 +1074,7 @@ static int b44_change_mtu(struct net_dev
 	b44_halt(bp);
 	dev->mtu = new_mtu;
 	b44_init_rings(bp);
-	b44_init_hw(bp, 1);
+	b44_init_hw(bp, B44_FULL_RESET);
 	spin_unlock_irq(&bp->lock);
 
 	b44_enable_ints(bp);
@@ -1366,12 +1371,12 @@ static int b44_set_mac_addr(struct net_d
  * packet processing.  Invoked with bp->lock held.
  */
 static void __b44_set_rx_mode(struct net_device *);
-static void b44_init_hw(struct b44 *bp, int full_reset)
+static void b44_init_hw(struct b44 *bp, int reset_kind)
 {
 	u32 val;
 
 	b44_chip_reset(bp);
-	if (full_reset) {
+	if (reset_kind == B44_FULL_RESET) {
 		b44_phy_reset(bp);
 		b44_setup_phy(bp);
 	}
@@ -1388,7 +1393,10 @@ static void b44_init_hw(struct b44 *bp, 
 	bw32(bp, B44_TXMAXLEN, bp->dev->mtu + ETH_HLEN + 8 + RX_HEADER_LEN);
 
 	bw32(bp, B44_TX_WMARK, 56); /* XXX magic */
-	if (full_reset) {
+	if (reset_kind == B44_PARTIAL_RESET) {
+		bw32(bp, B44_DMARX_CTRL, (DMARX_CTRL_ENABLE |
+				      (bp->rx_offset << DMARX_CTRL_ROSHIFT)));
+	} else {
 		bw32(bp, B44_DMATX_CTRL, DMATX_CTRL_ENABLE);
 		bw32(bp, B44_DMATX_ADDR, bp->tx_ring_dma + bp->dma_offset);
 		bw32(bp, B44_DMARX_CTRL, (DMARX_CTRL_ENABLE |
@@ -1399,9 +1407,6 @@ static void b44_init_hw(struct b44 *bp, 
 		bp->rx_prod = bp->rx_pending;
 
 		bw32(bp, B44_MIB_CTRL, MIB_CTRL_CLR_ON_READ);
-	} else {
-		bw32(bp, B44_DMARX_CTRL, (DMARX_CTRL_ENABLE |
-				      (bp->rx_offset << DMARX_CTRL_ROSHIFT)));
 	}
 
 	val = br32(bp, B44_ENET_CTRL);
@@ -1418,7 +1423,7 @@ static int b44_open(struct net_device *d
 		goto out;
 
 	b44_init_rings(bp);
-	b44_init_hw(bp, 1);
+	b44_init_hw(bp, B44_FULL_RESET);
 
 	b44_check_phy(bp);
 
@@ -1627,7 +1632,7 @@ static int b44_close(struct net_device *
 	netif_poll_enable(dev);
 
 	if (bp->flags & B44_FLAG_WOL_ENABLE) {
-		b44_init_hw(bp, 0);
+		b44_init_hw(bp, B44_PARTIAL_RESET);
 		b44_setup_wol(bp);
 	}
 
@@ -1902,7 +1907,7 @@ static int b44_set_ringparam(struct net_
 
 	b44_halt(bp);
 	b44_init_rings(bp);
-	b44_init_hw(bp, 1);
+	b44_init_hw(bp, B44_FULL_RESET);
 	netif_wake_queue(bp->dev);
 	spin_unlock_irq(&bp->lock);
 
@@ -1945,7 +1950,7 @@ static int b44_set_pauseparam(struct net
 	if (bp->flags & B44_FLAG_PAUSE_AUTO) {
 		b44_halt(bp);
 		b44_init_rings(bp);
-		b44_init_hw(bp, 1);
+		b44_init_hw(bp, B44_FULL_RESET);
 	} else {
 		__b44_set_flow_ctrl(bp, bp->flags);
 	}
@@ -2301,7 +2306,7 @@ static int b44_suspend(struct pci_dev *p
 
 	free_irq(dev->irq, dev);
 	if (bp->flags & B44_FLAG_WOL_ENABLE) {
-		b44_init_hw(bp, 0);
+		b44_init_hw(bp, B44_PARTIAL_RESET);
 		b44_setup_wol(bp);
 	}
 	pci_disable_device(pdev);
@@ -2326,7 +2331,7 @@ static int b44_resume(struct pci_dev *pd
 	spin_lock_irq(&bp->lock);
 
 	b44_init_rings(bp);
-	b44_init_hw(bp, 1);
+	b44_init_hw(bp, B44_FULL_RESET);
 	netif_device_attach(bp->dev);
 	spin_unlock_irq(&bp->lock);
 
-- 
/***************************************************
 *Neil Horman
 *Software Engineer
 *Red Hat, Inc.
 *nhorman@redhat.com
 *gpg keyid: 1024D / 0x92A74FA1
 *http://pgp.mit.edu
 ***************************************************/