[PATCH net] net: phy: ti: take into account all possible interrupt sources

From: Ioana Ciornei <ioana.ciornei@nxp.com>

The previous implementation of .handle_interrupt() did not take into
account the fact that all the interrupt status registers should be
acknowledged since multiple interrupt sources could be asserted.

Fix this by reading all the status registers before exiting with
IRQ_NONE or triggering the PHY state machine.

Fixes: 1d1ae3c6ca3f ("net: phy: ti: implement generic .handle_interrupt() callback")
Reported-by: Sven Schuchmann <redacted>
Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
---
 drivers/net/phy/dp83822.c   |  9 +++++----
 drivers/net/phy/dp83tc811.c | 11 ++++++-----
 2 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/drivers/net/phy/dp83822.c b/drivers/net/phy/dp83822.c
index be1224b4447b..f7a2ec150e54 100644
--- a/drivers/net/phy/dp83822.c
+++ b/drivers/net/phy/dp83822.c

@@ -290,6 +290,7 @@ static int dp83822_config_intr(struct phy_device *phydev)
 
 static irqreturn_t dp83822_handle_interrupt(struct phy_device *phydev)
 {
+	bool trigger_machine = false;
 	int irq_status;
 
 	/* The MISR1 and MISR2 registers are holding the interrupt status in

@@ -305,7 +306,7 @@ static irqreturn_t dp83822_handle_interrupt(struct phy_device *phydev)
 		return IRQ_NONE;
 	}
 	if (irq_status & ((irq_status & GENMASK(7, 0)) << 8))
-		goto trigger_machine;
+		trigger_machine = true;
 
 	irq_status = phy_read(phydev, MII_DP83822_MISR2);
 	if (irq_status < 0) {

@@ -313,11 +314,11 @@ static irqreturn_t dp83822_handle_interrupt(struct phy_device *phydev)
 		return IRQ_NONE;
 	}
 	if (irq_status & ((irq_status & GENMASK(7, 0)) << 8))
-		goto trigger_machine;
+		trigger_machine = true;
 
-	return IRQ_NONE;
+	if (!trigger_machine)
+		return IRQ_NONE;
 
-trigger_machine:
 	phy_trigger_machine(phydev);
 
 	return IRQ_HANDLED;

diff --git a/drivers/net/phy/dp83tc811.c b/drivers/net/phy/dp83tc811.c
index 688fadffb249..7ea32fb77190 100644
--- a/drivers/net/phy/dp83tc811.c
+++ b/drivers/net/phy/dp83tc811.c

@@ -264,6 +264,7 @@ static int dp83811_config_intr(struct phy_device *phydev)
 
 static irqreturn_t dp83811_handle_interrupt(struct phy_device *phydev)
 {
+	bool trigger_machine = false;
 	int irq_status;
 
 	/* The INT_STAT registers 1, 2 and 3 are holding the interrupt status

@@ -279,7 +280,7 @@ static irqreturn_t dp83811_handle_interrupt(struct phy_device *phydev)
 		return IRQ_NONE;
 	}
 	if (irq_status & ((irq_status & GENMASK(7, 0)) << 8))
-		goto trigger_machine;
+		trigger_machine = true;
 
 	irq_status = phy_read(phydev, MII_DP83811_INT_STAT2);
 	if (irq_status < 0) {

@@ -287,7 +288,7 @@ static irqreturn_t dp83811_handle_interrupt(struct phy_device *phydev)
 		return IRQ_NONE;
 	}
 	if (irq_status & ((irq_status & GENMASK(7, 0)) << 8))
-		goto trigger_machine;
+		trigger_machine = true;
 
 	irq_status = phy_read(phydev, MII_DP83811_INT_STAT3);
 	if (irq_status < 0) {

@@ -295,11 +296,11 @@ static irqreturn_t dp83811_handle_interrupt(struct phy_device *phydev)
 		return IRQ_NONE;
 	}
 	if (irq_status & ((irq_status & GENMASK(7, 0)) << 8))
-		goto trigger_machine;
+		trigger_machine = true;
 
-	return IRQ_NONE;
+	if (!trigger_machine)
+		return IRQ_NONE;
 
-trigger_machine:
 	phy_trigger_machine(phydev);
 
 	return IRQ_HANDLED;

-- 
2.30.0

On Fri, 26 Feb 2021 17:30:20 +0200 Ioana Ciornei wrote:

Would it be better to code it up as:

	irqreturn_t ret = IRQ_NONE;

	if (irq_status & ...)
		ret = IRQ_HANDLED;

	/* .. */

	if (ret != IRQ_NONE)
		phy_trigger_machine(phydev);

	return ret;

That reads a tiny bit better to me, but it's probably majorly
subjective so I'm happy with existing patch if you prefer it.

On Sun, Feb 28, 2021 at 12:00:27PM -0800, Jakub Kicinski wrote:

On Fri, 26 Feb 2021 17:30:20 +0200 Ioana Ciornei wrote:

quoted

diff --git a/drivers/net/phy/dp83822.c b/drivers/net/phy/dp83822.c
index be1224b4447b..f7a2ec150e54 100644
--- a/drivers/net/phy/dp83822.c
+++ b/drivers/net/phy/dp83822.c

@@ -290,6 +290,7 @@ static int dp83822_config_intr(struct phy_device *phydev)
 
 static irqreturn_t dp83822_handle_interrupt(struct phy_device *phydev)
 {
+	bool trigger_machine = false;
 	int irq_status;
 
 	/* The MISR1 and MISR2 registers are holding the interrupt status in

@@ -305,7 +306,7 @@ static irqreturn_t dp83822_handle_interrupt(struct phy_device *phydev)
 		return IRQ_NONE;
 	}
 	if (irq_status & ((irq_status & GENMASK(7, 0)) << 8))
-		goto trigger_machine;
+		trigger_machine = true;
 
 	irq_status = phy_read(phydev, MII_DP83822_MISR2);
 	if (irq_status < 0) {

@@ -313,11 +314,11 @@ static irqreturn_t dp83822_handle_interrupt(struct phy_device *phydev)
 		return IRQ_NONE;
 	}
 	if (irq_status & ((irq_status & GENMASK(7, 0)) << 8))
-		goto trigger_machine;
+		trigger_machine = true;
 
-	return IRQ_NONE;
+	if (!trigger_machine)
+		return IRQ_NONE;
 
-trigger_machine:
 	phy_trigger_machine(phydev);
 
 	return IRQ_HANDLED;

Would it be better to code it up as:

	irqreturn_t ret = IRQ_NONE;

	if (irq_status & ...)
		ret = IRQ_HANDLED;

	/* .. */

	if (ret != IRQ_NONE)
		phy_trigger_machine(phydev);

	return ret;

That reads a tiny bit better to me, but it's probably majorly
subjective so I'm happy with existing patch if you prefer it.

I think I prefer it as it is and this is because it would be in line
with all the other PHY drivers which do this:

	if (!(irq_status & int_enabled))
		return IRQ_NONE;

	phy_trigger_machine(phydev);

	return IRQ_HANDLED;

Ioana

On Mon, 1 Mar 2021 10:21:14 +0200 Ioana Ciornei wrote:

On Sun, Feb 28, 2021 at 12:00:27PM -0800, Jakub Kicinski wrote:

quoted

On Fri, 26 Feb 2021 17:30:20 +0200 Ioana Ciornei wrote:  

quoted

diff --git a/drivers/net/phy/dp83822.c b/drivers/net/phy/dp83822.c
index be1224b4447b..f7a2ec150e54 100644
--- a/drivers/net/phy/dp83822.c
+++ b/drivers/net/phy/dp83822.c

@@ -290,6 +290,7 @@ static int dp83822_config_intr(struct phy_device *phydev)
 
 static irqreturn_t dp83822_handle_interrupt(struct phy_device *phydev)
 {
+	bool trigger_machine = false;
 	int irq_status;
 
 	/* The MISR1 and MISR2 registers are holding the interrupt status in

@@ -305,7 +306,7 @@ static irqreturn_t dp83822_handle_interrupt(struct phy_device *phydev)
 		return IRQ_NONE;
 	}
 	if (irq_status & ((irq_status & GENMASK(7, 0)) << 8))
-		goto trigger_machine;
+		trigger_machine = true;
 
 	irq_status = phy_read(phydev, MII_DP83822_MISR2);
 	if (irq_status < 0) {

@@ -313,11 +314,11 @@ static irqreturn_t dp83822_handle_interrupt(struct phy_device *phydev)
 		return IRQ_NONE;
 	}
 	if (irq_status & ((irq_status & GENMASK(7, 0)) << 8))
-		goto trigger_machine;
+		trigger_machine = true;
 
-	return IRQ_NONE;
+	if (!trigger_machine)
+		return IRQ_NONE;
 
-trigger_machine:
 	phy_trigger_machine(phydev);
 
 	return IRQ_HANDLED;  

Would it be better to code it up as:

	irqreturn_t ret = IRQ_NONE;

	if (irq_status & ...)
		ret = IRQ_HANDLED;

	/* .. */

	if (ret != IRQ_NONE)
		phy_trigger_machine(phydev);

	return ret;

That reads a tiny bit better to me, but it's probably majorly
subjective so I'm happy with existing patch if you prefer it.  

I think I prefer it as it is and this is because it would be in line
with all the other PHY drivers which do this:

	if (!(irq_status & int_enabled))
		return IRQ_NONE;

	phy_trigger_machine(phydev);

Okay, applied, thanks!