[PATCH v4] usb: musb: Fix deferred probing

[Zhu Wang]

When platform_get_irq_byname() fails, it may return -EPROBE_DEFER,
which suggested deferred probing, it is very important to propagate it
upstream. We cannot override it with other error code.

Commit ce753ad1549c ("platform: finally disallow IRQ0 in
platform_get_irq() and its ilk") makes sure IRQ0 is not returned.

Signed-off-by: Zhu Wang <wangzhu9@xxxxxxxxxx>

---
Changes in v2:
- Update the commit message, present the reason of replacing the return
value of the probe.

---
Changes in v3:
- Update the commit message, explain in detail why the return value of
platform_get_irq_byname() cannot be override.

---
Changes in v4:
- Update the title to "Fix deferred probing".
- Update the commit message, emphasize the -EPROBE_DEFER cannot be
overwritten by other error code.
- Remove -next tag.
---
 drivers/usb/musb/musb_core.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
index ecbd3784bec3..b24adb5b399f 100644
--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -2610,8 +2610,8 @@ static int musb_probe(struct platform_device *pdev)
 	int		irq = platform_get_irq_byname(pdev, "mc");
 	void __iomem	*base;
 
-	if (irq <= 0)
-		return -ENODEV;
+	if (irq < 0)
+		return irq;
 
 	base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(base))
-- 
2.17.1