net: dsa: microchip: common: Fix checks on irq_find_mapping()

irq_find_mapping() returns a positive IRQ number or 0 if no IRQ is found
but it never returns a negative value. However, on each
irq_find_mapping() call, we verify that the returned value isn't
negative.

Fix the irq_find_mapping() checks to enter error paths when 0 is
returned. Return -EINVAL in such cases.

CC: stable@vger.kernel.org
Fixes: c9cd961c0d43 ("net: dsa: microchip: lan937x: add interrupt support for port phy link")
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Bastien Curutchet (Schneider Electric) <bastien.curutchet@bootlin.com>
Link: https://patch.msgid.link/20251120-ksz-fix-v6-1-891f80ae7f8f@bootlin.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c
index 933ae8dc633783f7e23c3f302fd737b30a7a8fe2..e684568a4edad68ae93712c0d5604958a08116d0 100644 (file)
--- a/drivers/net/dsa/microchip/ksz_common.c
+++ b/drivers/net/dsa/microchip/ksz_common.c
@@ -2587,8 +2587,8 @@ static int ksz_irq_phy_setup(struct ksz_device *dev)
 
                        irq = irq_find_mapping(dev->ports[port].pirq.domain,
                                               PORT_SRC_PHY_INT);
-                       if (irq < 0) {
-                               ret = irq;
+                       if (!irq) {
+                               ret = -EINVAL;
                                goto out;
                        }
                        ds->user_mii_bus->irq[phy] = irq;
@@ -2952,8 +2952,8 @@ static int ksz_pirq_setup(struct ksz_device *dev, u8 p)
        snprintf(pirq->name, sizeof(pirq->name), "port_irq-%d", p);
 
        pirq->irq_num = irq_find_mapping(dev->girq.domain, p);
-       if (pirq->irq_num < 0)
-               return pirq->irq_num;
+       if (!pirq->irq_num)
+               return -EINVAL;
 
        return ksz_irq_common_setup(dev, pirq);
 }