net: systemport: Fix WoL with password after deep sleep

Broadcom STB chips support a deep sleep mode where all register
contents are lost. Because we were stashing the MagicPacket password
into some of these registers a suspend into that deep sleep then a
resumption would not lead to being able to wake-up from MagicPacket with
password again.

Fix this by keeping a software copy of the password and program it
during suspend.

Fixes: 83e82f4c ("net: systemport: add Wake-on-LAN support")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bcmsysport.c

@@ -520,7 +520,6 @@ static void bcm_sysport_get_wol(struct net_device *dev,
 				struct ethtool_wolinfo *wol)
 {
 	struct bcm_sysport_priv *priv = netdev_priv(dev);
-	u32 reg;
 
 	wol->supported = WAKE_MAGIC | WAKE_MAGICSECURE | WAKE_FILTER;
 	wol->wolopts = priv->wolopts;
@@ -528,11 +527,7 @@ static void bcm_sysport_get_wol(struct net_device *dev,
 	if (!(priv->wolopts & WAKE_MAGICSECURE))
 		return;
 
-	/* Return the programmed SecureOn password */
-	reg = umac_readl(priv, UMAC_PSW_MS);
-	put_unaligned_be16(reg, &wol->sopass[0]);
-	reg = umac_readl(priv, UMAC_PSW_LS);
-	put_unaligned_be32(reg, &wol->sopass[2]);
+	memcpy(wol->sopass, priv->sopass, sizeof(priv->sopass));
 }
 
 static int bcm_sysport_set_wol(struct net_device *dev,
@@ -548,13 +543,8 @@ static int bcm_sysport_set_wol(struct net_device *dev,
 	if (wol->wolopts & ~supported)
 		return -EINVAL;
 
-	/* Program the SecureOn password */
-	if (wol->wolopts & WAKE_MAGICSECURE) {
-		umac_writel(priv, get_unaligned_be16(&wol->sopass[0]),
-			    UMAC_PSW_MS);
-		umac_writel(priv, get_unaligned_be32(&wol->sopass[2]),
-			    UMAC_PSW_LS);
-	}
+	if (wol->wolopts & WAKE_MAGICSECURE)
+		memcpy(priv->sopass, wol->sopass, sizeof(priv->sopass));
 
 	/* Flag the device and relevant IRQ as wakeup capable */
 	if (wol->wolopts) {
@@ -2649,13 +2639,18 @@ static int bcm_sysport_suspend_to_wol(struct bcm_sysport_priv *priv)
 	unsigned int index, i = 0;
 	u32 reg;
 
-	/* Password has already been programmed */
 	reg = umac_readl(priv, UMAC_MPD_CTRL);
 	if (priv->wolopts & (WAKE_MAGIC | WAKE_MAGICSECURE))
 		reg |= MPD_EN;
 	reg &= ~PSW_EN;
-	if (priv->wolopts & WAKE_MAGICSECURE)
+	if (priv->wolopts & WAKE_MAGICSECURE) {
+		/* Program the SecureOn password */
+		umac_writel(priv, get_unaligned_be16(&priv->sopass[0]),
+			    UMAC_PSW_MS);
+		umac_writel(priv, get_unaligned_be32(&priv->sopass[2]),
+			    UMAC_PSW_LS);
 		reg |= PSW_EN;
+	}
 	umac_writel(priv, reg, UMAC_MPD_CTRL);
 
 	if (priv->wolopts & WAKE_FILTER) {

drivers/net/ethernet/broadcom/bcmsysport.h

@@ -12,6 +12,7 @@
 #define __BCM_SYSPORT_H
 
 #include <linux/bitmap.h>
+#include <linux/ethtool.h>
 #include <linux/if_vlan.h>
 #include <linux/net_dim.h>
 
@@ -778,6 +779,7 @@ struct bcm_sysport_priv {
 	unsigned int		crc_fwd:1;
 	u16			rev;
 	u32			wolopts;
+	u8			sopass[SOPASS_MAX];
 	unsigned int		wol_irq_disabled:1;
 
 	/* MIB related fields */