[PATCH] net: can: cc770: don't discard the IRQ lookup error in probe

[Quchaosheng]

cc770_platform_probe() collapses every failure of platform_get_irq()
into -ENODEV:

	irq = platform_get_irq(pdev, 0);
	if (!mem || irq <= 0)
		return -ENODEV;

That discards -EPROBE_DEFER, so a probe that has to wait for its
interrupt controller is never retried and the device stays unbound.

Return the lookup error unchanged, which is what the neighbouring CAN
platform drivers already do (c_can_platform.c, flexcan-core.c,
sja1000_platform.c). A device tree without an interrupt now reports
-ENXIO rather than -ENODEV; the driver core treats those two the same
way, so the outcome does not change.

The memory resource is checked first and on its own, so a missing
region no longer triggers an IRQ lookup that cannot succeed.

Assisted-by: LLM
Signed-off-by: Quchaosheng <quchaosheng000406@xxxxxxx>
---
 drivers/net/can/cc770/cc770_platform.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/net/can/cc770/cc770_platform.c b/drivers/net/can/cc770/cc770_platform.c
index b6c4f02ffb97..64fbdf14e8ab 100644
--- a/drivers/net/can/cc770/cc770_platform.c
+++ b/drivers/net/can/cc770/cc770_platform.c
@@ -156,10 +156,13 @@ static int cc770_platform_probe(struct platform_device *pdev)
 	int err, irq;
 
 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	irq = platform_get_irq(pdev, 0);
-	if (!mem || irq <= 0)
+	if (!mem)
 		return -ENODEV;
 
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
 	mem_size = resource_size(mem);
 	if (!request_mem_region(mem->start, mem_size, pdev->name))
 		return -EBUSY;
-- 
2.43.0