Fix LAN8720 Link Problem When Ethernet Cable is not Plugged at Boot Up

Eric Lee
1 parent 6c1a649f77
Showing 1 changed file with 45 additions and 1 deletions Side-by-side Diff
drivers/net/phy/smsc.c
@@ -80,6 +80,49 @@
 	return smsc_phy_ack_interrupt(phydev);
 }
  
+/*
+ * 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.
+ */
+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 = 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);
+
+                /* Re-enable EDPD */
+                rc = phy_read(phydev, MII_LAN83C185_CTRL_STATUS);
+                if (rc < 0)
+                        return rc;
+
+                rc = phy_write(phydev, MII_LAN83C185_CTRL_STATUS,
+                               rc | MII_LAN83C185_EDPWRDOWN);
+                if (rc < 0)
+                        return rc;
+        }
+
+        return err;
+}
+
 static struct phy_driver lan83c185_driver = {
 	.phy_id		= 0x0007c0a0, /* OUI=0x00800f, Model#=0x0a */
 	.phy_id_mask	= 0xfffffff0,
@@ -187,7 +230,8 @@
  
 	/* basic functions */
 	.config_aneg	= genphy_config_aneg,
-	.read_status	= genphy_read_status,
+	/*.read_status	= genphy_read_status,*/
+        .read_status    = lan87xx_read_status,
 	.config_init	= smsc_phy_config_init,
  
 	/* IRQ related */
...	...	@@ -80,6 +80,49 @@
80	80	return smsc_phy_ack_interrupt(phydev);
81	81	}
82	82
	83	+/*
	84	+ * The LAN8710/LAN8720 requires a minimum of 2 link pulses within 64ms of each
	85	+ * other in order to set the ENERGYON bit and exit EDPD mode. If a link partner
	86	+ * does send the pulses within this interval, the PHY will remained powered
	87	+ * down.
	88	+ *
	89	+ * This workaround will manually toggle the PHY on/off upon calls to read_status
	90	+ * in order to generate link test pulses if the link is down. If a link partner
	91	+ * is present, it will respond to the pulses, which will cause the ENERGYON bit
	92	+ * to be set and will cause the EDPD mode to be exited.
	93	+ */
	94	+static int lan87xx_read_status(struct phy_device *phydev)
	95	+{
	96	+ int err = genphy_read_status(phydev);
	97	+
	98	+ if (!phydev->link) {
	99	+ /* Disable EDPD to wake up PHY */
	100	+ int rc = phy_read(phydev, MII_LAN83C185_CTRL_STATUS);
	101	+ if (rc < 0)
	102	+ return rc;
	103	+
	104	+ rc = phy_write(phydev, MII_LAN83C185_CTRL_STATUS,
	105	+ rc & ~MII_LAN83C185_EDPWRDOWN);
	106	+ if (rc < 0)
	107	+ return rc;
	108	+
	109	+ /* Sleep 64 ms to allow ~5 link test pulses to be sent */
	110	+ msleep(64);
	111	+
	112	+ /* Re-enable EDPD */
	113	+ rc = phy_read(phydev, MII_LAN83C185_CTRL_STATUS);
	114	+ if (rc < 0)
	115	+ return rc;
	116	+
	117	+ rc = phy_write(phydev, MII_LAN83C185_CTRL_STATUS,
	118	+ rc \| MII_LAN83C185_EDPWRDOWN);
	119	+ if (rc < 0)
	120	+ return rc;
	121	+ }
	122	+
	123	+ return err;
	124	+}
	125	+
83	126	static struct phy_driver lan83c185_driver = {
84	127	.phy_id = 0x0007c0a0, /* OUI=0x00800f, Model#=0x0a */
85	128	.phy_id_mask = 0xfffffff0,
...	...	@@ -187,7 +230,8 @@
187	230
188	231	/* basic functions */
189	232	.config_aneg = genphy_config_aneg,
190		- .read_status = genphy_read_status,
	233	+ /.read_status = genphy_read_status,/
	234	+ .read_status = lan87xx_read_status,
191	235	.config_init = smsc_phy_config_init,
192	236
193	237	/* IRQ related */