[PATCH net v2 2/4] net: dsa: microchip: ptp: Fix checks on irq_find_mapping()

Bastien Curutchet (Schneider Electric)
2025-11-06T12:53:20Z

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

Fix the irq_find_mapping() check to enter the error path when 0 is
returned. Return -EINVAL in such case.

Fixes: cc13ab18b201 ("net: dsa: microchip: ptp: enable interrupt for timestamping")
Signed-off-by: Bastien Curutchet (Schneider Electric) <bastien.curutchet@bootlin.com>
---
drivers/net/dsa/microchip/ksz_ptp.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/dsa/microchip/ksz_ptp.c b/drivers/net/dsa/microchip/ksz_ptp.c
index 35fc21b1ee48a47daa278573bfe8749c7b42c731..c8bfbe5e2157323ecf29149d1907b77e689aa221 100644
--- a/drivers/net/dsa/microchip/ksz_ptp.c
+++ b/drivers/net/dsa/microchip/ksz_ptp.c
@@ -1139,8 +1139,8 @@ int ksz_ptp_irq_setup(struct dsa_switch *ds, u8 p)
irq_create_mapping(ptpirq->domain, irq);

ptpirq->irq_num = irq_find_mapping(port->pirq.domain, PORT_SRC_PTP_INT);
- if (ptpirq->irq_num < 0) {
- ret = ptpirq->irq_num;
+ if (!ptpirq->irq_num) {
+ ret = -EINVAL;
goto out;
}

--
2.51.0