Commit 4223dbff authored by Patrick Trantham's avatar Patrick Trantham Committed by David S. Miller
Browse files

net: phy: smsc: Re-enable EDPD mode for LAN87xx 



This patch re-enables Energy Detect Power Down (EDPD) mode for the
LAN8710/LAN8720.  EDPD mode was disabled in a previous commit,
(b629820d), because it was causing the
PHY to not be able to detect a link when cold started without a cable
connected.

The LAN8710/LAN8720 requires a minimum of 2 link pulses within 64ms of
each other in order to set the ENERGYON bit and exit EDPD mode.  If a
link partner does send the pulses within this interval, the PHY will
remained powered down.

This workaround will manually toggle the PHY on/off upon calls to
read_status in order to generate link test pulses if the link is down.
If a link partner is present, it will respond to the pulses, which will
cause the ENERGYON bit to be set and will cause the EDPD mode to be
exited.

Signed-off-by: default avatarPatrick Trantham <patrick.trantham@fuel7.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent f191a1d1

drivers/net/phy/smsc.c

+43 −26
Original line number Diff line number Diff line
@@ -56,35 +56,52 @@ static int smsc_phy_config_init(struct phy_device *phydev) 
	return smsc_phy_ack_interrupt (phydev);

}



static int lan87xx_config_init(struct phy_device *phydev)

static int lan911x_config_init(struct phy_device *phydev)

{

	return smsc_phy_ack_interrupt(phydev);

}



/*

	 * Make sure the EDPWRDOWN bit is NOT set. Setting this bit on

	 * LAN8710/LAN8720 PHY causes the PHY to misbehave, likely due

	 * to a bug on the chip.

 * The LAN8710/LAN8720 requires a minimum of 2 link pulses within 64ms of each

 * other in order to set the ENERGYON bit and exit EDPD mode.  If a link partner

 * does send the pulses within this interval, the PHY will remained powered

 * down.

 *

	 * When the system is powered on with the network cable being

	 * disconnected all the way until after ifconfig ethX up is

	 * issued for the LAN port with this PHY, connecting the cable

	 * afterwards does not cause LINK change detection, while the

	 * expected behavior is the Link UP being detected.

 * This workaround will manually toggle the PHY on/off upon calls to read_status

 * in order to generate link test pulses if the link is down.  If a link partner

 * is present, it will respond to the pulses, which will cause the ENERGYON bit

 * to be set and will cause the EDPD mode to be exited.

 */

static int lan87xx_read_status(struct phy_device *phydev)

{

	int err = genphy_read_status(phydev);



	if (!phydev->link) {

		/* Disable EDPD to wake up PHY */

		int rc = phy_read(phydev, MII_LAN83C185_CTRL_STATUS);

		if (rc < 0)

			return rc;



	rc &= ~MII_LAN83C185_EDPWRDOWN;

		rc = phy_write(phydev, MII_LAN83C185_CTRL_STATUS,

			       rc & ~MII_LAN83C185_EDPWRDOWN);

		if (rc < 0)

			return rc;



		/* Sleep 64 ms to allow ~5 link test pulses to be sent */

		msleep(64);



	rc = phy_write(phydev, MII_LAN83C185_CTRL_STATUS, rc);

		/* Re-enable EDPD */

		rc = phy_read(phydev, MII_LAN83C185_CTRL_STATUS);

		if (rc < 0)

			return rc;



	return smsc_phy_ack_interrupt(phydev);

		rc = phy_write(phydev, MII_LAN83C185_CTRL_STATUS,

			       rc | MII_LAN83C185_EDPWRDOWN);

		if (rc < 0)

			return rc;

	}



static int lan911x_config_init(struct phy_device *phydev)

{

	return smsc_phy_ack_interrupt(phydev);

	return err;

}



static struct phy_driver smsc_phy_driver[] = {
@@ -187,8 +204,8 @@ static struct phy_driver smsc_phy_driver[] = { 


	/* basic functions */

	.config_aneg	= genphy_config_aneg,

	.read_status	= genphy_read_status,

	.config_init	= lan87xx_config_init,

	.read_status	= lan87xx_read_status,

	.config_intr	= smsc_phy_config_intr,



	/* IRQ related */

	.ack_interrupt	= smsc_phy_ack_interrupt,

CRA Git | Maintained and supported by SUSTech CRA and CCSE