[PATCH v4] usb: gadget: udc: gr_udc: Fix deferred probing

[Zhu Wang]

When platform_get_irq() 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() 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/gadget/udc/gr_udc.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/gadget/udc/gr_udc.c b/drivers/usb/gadget/udc/gr_udc.c
index 0c3969301a53..c6dfa7cccc11 100644
--- a/drivers/usb/gadget/udc/gr_udc.c
+++ b/drivers/usb/gadget/udc/gr_udc.c
@@ -2136,15 +2136,15 @@ static int gr_probe(struct platform_device *pdev)
 		return PTR_ERR(regs);
 
 	dev->irq = platform_get_irq(pdev, 0);
-	if (dev->irq <= 0)
-		return -ENODEV;
+	if (dev->irq < 0)
+		return dev->irq;
 
 	/* Some core configurations has separate irqs for IN and OUT events */
 	dev->irqi = platform_get_irq(pdev, 1);
 	if (dev->irqi > 0) {
 		dev->irqo = platform_get_irq(pdev, 2);
-		if (dev->irqo <= 0)
-			return -ENODEV;
+		if (dev->irqo < 0)
+			return dev->irqo;
 	} else {
 		dev->irqi = 0;
 	}
-- 
2.17.1