When platform_get_irq_byname() failed, it may return -EPROBE_DEFER,
-EINVAL or -ENXIO, it is important to propagate the detail upstream, we
cannot override it.

And platform_get_irq_byname() used to return 0 (as both IRQ0 and error
indication), there are several patches fixing the inconsistencies.

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@huawei.com>

---
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.
---
 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

On 8/3/23 3:00 PM, Zhu Wang wrote:

> When platform_get_irq_byname() failed, it may return -EPROBE_DEFER,

   s/failed/fails/, I think...

> -EINVAL or -ENXIO, it is important to propagate the detail upstream, we
> cannot override it.

   You better rename the patch to something like "usb: musb: Fix deferred
probing" now. And remove "-next:, as this became a real fix.

> And platform_get_irq_byname() used to return 0 (as both IRQ0 and error
> indication), there are several patches fixing the inconsistencies.

   In no way I suggested to take my "historical" passage into the
patch description!

> 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@huawei.com>
> 
> ---
> 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.

   You didn't emphasize the deferred probing breakage we're trying to
fix here at last; the other error codes here are not very important...

[...]

MBR, Sergey