Patch "net: phy: smsc: Cache interrupt mask" has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    net: phy: smsc: Cache interrupt mask

to the 5.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     net-phy-smsc-cache-interrupt-mask.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit b64a960e4385d145b98800b2839f59c6d5c8554b
Author: Lukas Wunner <lukas@xxxxxxxxx>
Date:   Thu May 12 10:42:06 2022 +0200

    net: phy: smsc: Cache interrupt mask
    
    [ Upstream commit 7e8b617eb93f9fcaedac02cd19edcad31c767386 ]
    
    Cache the interrupt mask to avoid re-reading it from the PHY upon every
    interrupt.
    
    This will simplify a subsequent commit which detects hot-removal in the
    interrupt handler and bails out.
    
    Analyzing and debugging PHY transactions also becomes simpler if such
    redundant reads are avoided.
    
    Last not least, interrupt overhead and latency is slightly improved.
    
    Tested-by: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx> # LAN9514/9512/9500
    Tested-by: Ferry Toth <fntoth@xxxxxxxxx> # LAN9514
    Signed-off-by: Lukas Wunner <lukas@xxxxxxxxx>
    Reviewed-by: Andrew Lunn <andrew@xxxxxxx>
    Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
    Stable-dep-of: 58aac3a2ef41 ("net: phy: smsc: fix link up detection in forced irq mode")
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/net/phy/smsc.c b/drivers/net/phy/smsc.c
index 636b0907a5987..63dca3bb56110 100644
--- a/drivers/net/phy/smsc.c
+++ b/drivers/net/phy/smsc.c
@@ -44,6 +44,7 @@ static struct smsc_hw_stat smsc_hw_stats[] = {
 };
 
 struct smsc_phy_priv {
+	u16 intmask;
 	bool energy_enable;
 	struct clk *refclk;
 };
@@ -58,7 +59,6 @@ static int smsc_phy_ack_interrupt(struct phy_device *phydev)
 static int smsc_phy_config_intr(struct phy_device *phydev)
 {
 	struct smsc_phy_priv *priv = phydev->priv;
-	u16 intmask = 0;
 	int rc;
 
 	if (phydev->interrupts == PHY_INTERRUPT_ENABLED) {
@@ -66,12 +66,15 @@ static int smsc_phy_config_intr(struct phy_device *phydev)
 		if (rc)
 			return rc;
 
-		intmask = MII_LAN83C185_ISF_INT4 | MII_LAN83C185_ISF_INT6;
+		priv->intmask = MII_LAN83C185_ISF_INT4 | MII_LAN83C185_ISF_INT6;
 		if (priv->energy_enable)
-			intmask |= MII_LAN83C185_ISF_INT7;
-		rc = phy_write(phydev, MII_LAN83C185_IM, intmask);
+			priv->intmask |= MII_LAN83C185_ISF_INT7;
+
+		rc = phy_write(phydev, MII_LAN83C185_IM, priv->intmask);
 	} else {
-		rc = phy_write(phydev, MII_LAN83C185_IM, intmask);
+		priv->intmask = 0;
+
+		rc = phy_write(phydev, MII_LAN83C185_IM, 0);
 		if (rc)
 			return rc;
 
@@ -83,13 +86,8 @@ static int smsc_phy_config_intr(struct phy_device *phydev)
 
 static irqreturn_t smsc_phy_handle_interrupt(struct phy_device *phydev)
 {
-	int irq_status, irq_enabled;
-
-	irq_enabled = phy_read(phydev, MII_LAN83C185_IM);
-	if (irq_enabled < 0) {
-		phy_error(phydev);
-		return IRQ_NONE;
-	}
+	struct smsc_phy_priv *priv = phydev->priv;
+	int irq_status;
 
 	irq_status = phy_read(phydev, MII_LAN83C185_ISF);
 	if (irq_status < 0) {
@@ -97,7 +95,7 @@ static irqreturn_t smsc_phy_handle_interrupt(struct phy_device *phydev)
 		return IRQ_NONE;
 	}
 
-	if (!(irq_status & irq_enabled))
+	if (!(irq_status & priv->intmask))
 		return IRQ_NONE;
 
 	phy_trigger_machine(phydev);