diff mbox series

[net-next,v3,6/7] net: phy: smsc: Cache interrupt mask

Message ID cf9f1b5d1b07e0fa5f78bc8557216ef04f401af5.1652343655.git.lukas@wunner.de (mailing list archive)
State Accepted
Commit 7e8b617eb93f9fcaedac02cd19edcad31c767386
Delegated to: Netdev Maintainers
Headers show
Series Polling be gone on LAN95xx | expand

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Context Check Description
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers success CCed 8 of 8 maintainers
netdev/build_clang success Errors and warnings before: 0 this patch: 0
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 56 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Lukas Wunner May 12, 2022, 8:42 a.m. UTC 
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@pengutronix.de> # LAN9514/9512/9500
Tested-by: Ferry Toth <fntoth@gmail.com> # LAN9514
Signed-off-by: Lukas Wunner <lukas@wunner.de>
---
 drivers/net/phy/smsc.c | 24 +++++++++++-------------
 1 file changed, 11 insertions(+), 13 deletions(-)

Comments

Lukas Wunner May 12, 2022, 12:17 p.m. UTC | #1 
On Thu, May 12, 2022 at 10:42:06AM +0200, Lukas Wunner wrote:
> 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@pengutronix.de> # LAN9514/9512/9500
> Tested-by: Ferry Toth <fntoth@gmail.com> # LAN9514
> Signed-off-by: Lukas Wunner <lukas@wunner.de>

Reviewed-by: Andrew Lunn <andrew@lunn.ch>

Andrew kindly provided this tag here:
https://lore.kernel.org/netdev/YnGsDtscYkh28PFm@lunn.ch/

Forgot to add it to the commit.
Sending it in separately so patchwork picks it up.
My apologies for the inconvenience.
diff mbox series

Patch

diff --git a/drivers/net/phy/smsc.c b/drivers/net/phy/smsc.c
index 92225d0fc246..e0eadea4b4b5 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);