[PATCH net-next 4/4] can: ifi_canfd: don't discard the IRQ lookup error in probe

[Chaosheng Qu]

ifi_canfd_plat_probe() maps every failure of platform_get_irq() to
-EINVAL:

	irq = platform_get_irq(pdev, 0);
	if (irq < 0)
		return -EINVAL;

The driver matches through an of_match_table ("ifi,canfd-1.0"), so
of_irq_get() returns -EPROBE_DEFER while the interrupt controller has not
been probed. The probe overwrites it and the driver core stops retrying,
leaving the device unbound even though the interrupt controller appears
later.

Return the lookup error unchanged, as the neighbouring CAN platform
drivers do, e.g. commit 057bd6168d98 ("can: cc770: don't discard the IRQ
lookup error in probe").

A device tree without an interrupt now reports -ENXIO rather than
-EINVAL; the driver core treats both as a failed probe.

Build tested on x86_64.

Assisted-by: LLM
Signed-off-by: Chaosheng Qu <chaosheng.qu.linux@xxxxxxxxx>
---
 drivers/net/can/ifi_canfd/ifi_canfd.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/can/ifi_canfd/ifi_canfd.c b/drivers/net/can/ifi_canfd/ifi_canfd.c
index 9eecfe5a87bd..e0f5abd934fa 100644
--- a/drivers/net/can/ifi_canfd/ifi_canfd.c
+++ b/drivers/net/can/ifi_canfd/ifi_canfd.c
@@ -965,7 +965,7 @@ static int ifi_canfd_plat_probe(struct platform_device *pdev)
 
 	irq = platform_get_irq(pdev, 0);
 	if (irq < 0)
-		return -EINVAL;
+		return irq;
 
 	id = readl(addr + IFI_CANFD_IP_ID);
 	if (id != IFI_CANFD_IP_ID_VALUE) {
-- 
2.43.0