[PATCH net v5 2/2] net: fec: Handle optional IRQ lookup errors correctly

[phucduc.bui@gmail.com]

From: bui duc phuc <phucduc.bui@gmail.com>

Handle errors from platform_get_irq_byname_optional() explicitly while
preserving the existing fallback to platform_get_irq() when the named IRQ
is not available.

Propagate errors other than -ENXIO from the optional IRQ lookup instead
of silently falling back to the indexed IRQ lookup.

In particular, silently ignoring -EPROBE_DEFER can cause the driver to
continue probing instead of deferring as required.

Fixes: 3b56be218f65 ("net: fec_main: Use platform_get_irq_byname_optional() to avoid error message")
Signed-off-by: bui duc phuc <phucduc.bui@gmail.com>
---
 drivers/net/ethernet/freescale/fec_main.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index c6e29b5c2abb..f7636f23d1eb 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -5397,12 +5397,17 @@ fec_probe(struct platform_device *pdev)
 	for (i = 0; i < irq_cnt; i++) {
 		snprintf(irq_name, sizeof(irq_name), "int%d", i);
 		irq = platform_get_irq_byname_optional(pdev, irq_name);
-		if (irq < 0)
-			irq = platform_get_irq(pdev, i);
-		if (irq < 0) {
+		if (irq < 0 && irq != -ENXIO) {
 			ret = irq;
 			goto failed_irq;
 		}
+		if (irq == -ENXIO) {
+			irq = platform_get_irq(pdev, i);
+			if (irq < 0) {
+				ret = irq;
+				goto failed_irq;
+			}
+		}
 		ret = devm_request_irq(&pdev->dev, irq, fec_enet_interrupt,
 				       0, pdev->name, ndev);
 		if (ret)
-- 
2.43.0