2005-01-20 12:13:43

by Ian Campbell

Subject: [PATCH] smc91x: power down PHY on suspend

Hi,

Powering down the PHY saves something like 100mA at 5V on my platform.
Currently it is only done when the interface is brought down but it
makes sense to do it on suspend as well.

Signed-off-by: Ian Campbell <[email protected]>

Index: 2.6/drivers/net/smc91x.c
===================================================================
--- 2.6.orig/drivers/net/smc91x.c 2005-01-17 11:04:43.000000000 +0000
+++ 2.6/drivers/net/smc91x.c 2005-01-20 12:11:09.292758475 +0000
@@ -1013,13 +1008,29 @@
/*
* smc_phy_powerdown - powerdown phy
* @dev: net device
- * @phy: phy address
*
* Power down the specified PHY
*/
-static void smc_phy_powerdown(struct net_device *dev, int phy)
+static void smc_phy_powerdown(struct net_device *dev)
{
+ struct smc_local *lp = netdev_priv(dev);
unsigned int bmcr;
+ int phy = lp->mii.phy_id;
+
+ if (lp->phy_type == 0)
+ return;
+
+ /* We need to ensure that no calls to smc_phy_configure are
+ pending.
+
+ flush_scheduled_work() cannot be called because we are
+ running with the netlink semaphore held (from
+ devinet_ioctl()) and the pending work queue contains
+ linkwatch_event() (scheduled by netif_carrier_off()
+ above). linkwatch_event() also wants the netlink semaphore.
+ */
+ while(lp->work_pending)
+ schedule();

bmcr = smc_phy_read(dev, phy, MII_BMCR);
smc_phy_write(dev, phy, MII_BMCR, bmcr | BMCR_PDOWN);
@@ -1544,21 +1555,7 @@
/* clear everything */
smc_shutdown(dev);

- if (lp->phy_type != 0) {
- /* We need to ensure that no calls to
- smc_phy_configure are pending.
-
- flush_scheduled_work() cannot be called because we
- are running with the netlink semaphore held (from
- devinet_ioctl()) and the pending work queue
- contains linkwatch_event() (scheduled by
- netif_carrier_off() above). linkwatch_event() also
- wants the netlink semaphore.
- */
- while(lp->work_pending)
- schedule();
- smc_phy_powerdown(dev, lp->mii.phy_id);
- }
+ smc_phy_powerdown(dev);

if (lp->pending_tx_skb) {
dev_kfree_skb(lp->pending_tx_skb);
@@ -2176,6 +2179,7 @@
if (netif_running(ndev)) {
netif_device_detach(ndev);
smc_shutdown(ndev);
+ smc_phy_powerdown(ndev);
}
}
return 0;



--
Ian Campbell, Senior Design Engineer
Web: http://www.arcom.com
Arcom, Clifton Road, Direct: +44 (0)1223 403 465
Cambridge CB1 7EA, United Kingdom Phone: +44 (0)1223 411 200

2005-01-20 15:19:04

by Nicolas Pitre

Subject: Re: [PATCH] smc91x: power down PHY on suspend

On Thu, 20 Jan 2005, Ian Campbell wrote:

> Hi,
>
> Powering down the PHY saves something like 100mA at 5V on my platform.
> Currently it is only done when the interface is brought down but it
> makes sense to do it on suspend as well.
>
> Signed-off-by: Ian Campbell <[email protected]>

Signed-off-by: Nicolas Pitre <[email protected]>

>
> Index: 2.6/drivers/net/smc91x.c
> ===================================================================
> --- 2.6.orig/drivers/net/smc91x.c 2005-01-17 11:04:43.000000000 +0000
> +++ 2.6/drivers/net/smc91x.c 2005-01-20 12:11:09.292758475 +0000
> @@ -1013,13 +1008,29 @@
> /*
> * smc_phy_powerdown - powerdown phy
> * @dev: net device
> - * @phy: phy address
> *
> * Power down the specified PHY
> */
> -static void smc_phy_powerdown(struct net_device *dev, int phy)
> +static void smc_phy_powerdown(struct net_device *dev)
> {
> + struct smc_local *lp = netdev_priv(dev);
> unsigned int bmcr;
> + int phy = lp->mii.phy_id;
> +
> + if (lp->phy_type == 0)
> + return;
> +
> + /* We need to ensure that no calls to smc_phy_configure are
> + pending.
> +
> + flush_scheduled_work() cannot be called because we are
> + running with the netlink semaphore held (from
> + devinet_ioctl()) and the pending work queue contains
> + linkwatch_event() (scheduled by netif_carrier_off()
> + above). linkwatch_event() also wants the netlink semaphore.
> + */
> + while(lp->work_pending)
> + schedule();
>
> bmcr = smc_phy_read(dev, phy, MII_BMCR);
> smc_phy_write(dev, phy, MII_BMCR, bmcr | BMCR_PDOWN);
> @@ -1544,21 +1555,7 @@
> /* clear everything */
> smc_shutdown(dev);
>
> - if (lp->phy_type != 0) {
> - /* We need to ensure that no calls to
> - smc_phy_configure are pending.
> -
> - flush_scheduled_work() cannot be called because we
> - are running with the netlink semaphore held (from
> - devinet_ioctl()) and the pending work queue
> - contains linkwatch_event() (scheduled by
> - netif_carrier_off() above). linkwatch_event() also
> - wants the netlink semaphore.
> - */
> - while(lp->work_pending)
> - schedule();
> - smc_phy_powerdown(dev, lp->mii.phy_id);
> - }
> + smc_phy_powerdown(dev);
>
> if (lp->pending_tx_skb) {
> dev_kfree_skb(lp->pending_tx_skb);
> @@ -2176,6 +2179,7 @@
> if (netif_running(ndev)) {
> netif_device_detach(ndev);
> smc_shutdown(ndev);
> + smc_phy_powerdown(ndev);
> }
> }
> return 0;
>
>
>
> --
> Ian Campbell, Senior Design Engineer
> Web: http://www.arcom.com
> Arcom, Clifton Road, Direct: +44 (0)1223 403 465
> Cambridge CB1 7EA, United Kingdom Phone: +44 (0)1223 411 200
>


Nicolas