[PATCH] b44: power down PHY when interface down

["Török Edvin" <edwintorok@gmail.com>]

When the interface is down (or driver removed), the BroadCom 44xx card remains
powered on, and both its MAC and PHY is using up power.
This patch makes the driver issue a MAC_CTRL_PHY_PDOWN when the interface
is halted, and does a partial chip reset turns off the activity LEDs too.

Applies to 2.6.22-rc6, or current git head.

Tested on a Broadcom BCM4401-B0 card, it saves ~0.5W (measured using powertop).

Signed-off-by: Torok Edwin <edwintorok@gmail.com>
---
b44.c |   25 ++++++++++++++++++++-----
 1 file changed, 20 insertions(+), 5 deletions(-)
diff --git a/drivers/net/b44.c b/drivers/net/b44.c
index 879a2ff..00d0f57 100644
--- a/drivers/net/b44.c
+++ b/drivers/net/b44.c
@@ -113,6 +113,8 @@ static void b44_init_rings(struct b44 *);
#define B44_FULL_RESET		1
#define B44_FULL_RESET_SKIP_PHY	2
#define B44_PARTIAL_RESET	3
+#define B44_CHIP_RESET_FULL     4
+#define B44_CHIP_RESET_PARTIAL  5

static void b44_init_hw(struct b44 *, int);

@@ -1283,7 +1285,7 @@ static void b44_clear_stats(struct b44 *bp)
}

/* bp->lock is held. */
-static void b44_chip_reset(struct b44 *bp)
+static void b44_chip_reset(struct b44 *bp, int reset_kind)
{
	if (ssb_is_core_up(bp)) {
		bw32(bp, B44_RCV_LAZY, 0);
@@ -1307,6 +1309,10 @@ static void b44_chip_reset(struct b44 *bp)

	b44_clear_stats(bp);

+	if (reset_kind == B44_CHIP_RESET_PARTIAL)
+		return;/* don't enable PHY if we are doing a partial reset
+		, we are probably going to power down */
+
	/* Make PHY accessible. */
	bw32(bp, B44_MDIO_CTRL, (MDIO_CTRL_PREAMBLE |
			     (0x0d & MDIO_CTRL_MAXF_MASK)));
@@ -1332,7 +1338,14 @@ static void b44_chip_reset(struct b44 *bp)
static void b44_halt(struct b44 *bp)
{
	b44_disable_ints(bp);
-	b44_chip_reset(bp);
+	/* reset PHY */
+	b44_phy_reset(bp);
+	/* power down PHY */
+	printk(KERN_INFO PFX "%s: powering down PHY\n", bp->dev->name);
+	bw32(bp, B44_MAC_CTRL, MAC_CTRL_PHY_PDOWN);
+	/* now reset the chip, but without enabling the MAC&PHY
+	 * part of it. This has to be done _after_ we shut down the PHY */
+	b44_chip_reset(bp, B44_CHIP_RESET_PARTIAL);
}

/* bp->lock is held. */
@@ -1376,7 +1389,7 @@ static void b44_init_hw(struct b44 *bp, int reset_kind)
{
	u32 val;

-	b44_chip_reset(bp);
+	b44_chip_reset(bp, B44_CHIP_RESET_FULL);
	if (reset_kind == B44_FULL_RESET) {
		b44_phy_reset(bp);
		b44_setup_phy(bp);
@@ -1430,7 +1443,7 @@ static int b44_open(struct net_device *dev)

	err = request_irq(dev->irq, b44_interrupt, IRQF_SHARED, dev->name, dev);
	if (unlikely(err < 0)) {
-		b44_chip_reset(bp);
+		b44_chip_reset(bp, B44_CHIP_RESET_PARTIAL);
		b44_free_rings(bp);
		b44_free_consistent(bp);
		goto out;
@@ -2250,7 +2263,7 @@ static int __devinit b44_init_one(struct pci_dev *pdev,
	/* Chip reset provides power to the b44 MAC & PCI cores, which
	 * is necessary for MAC register access.
	 */
-	b44_chip_reset(bp);
+	b44_chip_reset(bp, B44_CHIP_RESET_FULL);

	printk(KERN_INFO "%s: Broadcom 4400 10/100BaseT Ethernet ", dev->name);
	for (i = 0; i < 6; i++)
@@ -2284,6 +2297,7 @@ static void __devexit b44_remove_one(struct pci_dev *pdev)
	free_netdev(dev);
	pci_release_regions(pdev);
	pci_disable_device(pdev);
+	pci_set_power_state(pdev, PCI_D3hot);
	pci_set_drvdata(pdev, NULL);
}

@@ -2312,6 +2326,7 @@ static int b44_suspend(struct pci_dev *pdev,
pm_message_t state)
		b44_setup_wol(bp);
	}
	pci_disable_device(pdev);
+	pci_set_power_state(pdev, PCI_D3hot);
	return 0;
}
-
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