When the interrupt is enabled, the function lan8841_config_intr tries to
clear any pending interrupts by reading the interrupt status, then
checks the return value for errors and then continue to enable the
interrupt. It has been seen that once the system gets out of sleep mode,
the interrupt status has the value 0x400 meaning that the PHY detected
that the link was in low power. That is correct value but the problem is
that the check is wrong.  We try to check for errors but we return an
error also in this case which is not an error. Therefore fix this by
returning only when there is an error.

Fixes: a8f1a19d27ef ("net: micrel: Add support for lan8841 PHY")
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
---
v1->v2:
- do the same also in case the interrupts are disabled.
---
 drivers/net/phy/micrel.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
index 13e30ea7eec5d..c0773d74d5104 100644
--- a/drivers/net/phy/micrel.c
+++ b/drivers/net/phy/micrel.c
@@ -4029,7 +4029,7 @@ static int lan8841_config_intr(struct phy_device *phydev)
 
 	if (phydev->interrupts == PHY_INTERRUPT_ENABLED) {
 		err = phy_read(phydev, LAN8814_INTS);
-		if (err)
+		if (err < 0)
 			return err;
 
 		/* Enable / disable interrupts. It is OK to enable PTP interrupt
@@ -4045,6 +4045,14 @@ static int lan8841_config_intr(struct phy_device *phydev)
 			return err;
 
 		err = phy_read(phydev, LAN8814_INTS);
+		if (err < 0)
+			return err;
+
+		/* Getting a positive value doesn't mean that is an error, it
+		 * just indicates what was the status. Therefore make sure to
+		 * clear the value and say that there is no error.
+		 */
+		err = 0;
 	}
 
 	return err;
-- 
2.34.1

On Fri, May 24, 2024 at 10:53:50AM +0200, Horatiu Vultur wrote:
> When the interrupt is enabled, the function lan8841_config_intr tries to
> clear any pending interrupts by reading the interrupt status, then
> checks the return value for errors and then continue to enable the
> interrupt. It has been seen that once the system gets out of sleep mode,
> the interrupt status has the value 0x400 meaning that the PHY detected
> that the link was in low power. That is correct value but the problem is
> that the check is wrong.  We try to check for errors but we return an
> error also in this case which is not an error. Therefore fix this by
> returning only when there is an error.
> 
> Fixes: a8f1a19d27ef ("net: micrel: Add support for lan8841 PHY")
> Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>

LGTM.

Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

Thanks!

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!

On Fri, May 24, 2024 at 10:53:50AM +0200, Horatiu Vultur wrote:
> When the interrupt is enabled, the function lan8841_config_intr tries to
> clear any pending interrupts by reading the interrupt status, then
> checks the return value for errors and then continue to enable the
> interrupt. It has been seen that once the system gets out of sleep mode,
> the interrupt status has the value 0x400 meaning that the PHY detected
> that the link was in low power. That is correct value but the problem is
> that the check is wrong.  We try to check for errors but we return an
> error also in this case which is not an error. Therefore fix this by
> returning only when there is an error.
> 
> Fixes: a8f1a19d27ef ("net: micrel: Add support for lan8841 PHY")
> Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>

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

    Andrew