The __get_dwc3_maximum_speed() function returns an enum type which, in
this context here, is basically unsigned int.  On error cases, it's
supposed to return USB_SPEED_UNKNOWN, but it was accidentally changed to
return negative error codes in commit f93e96c544ca ("usb: dwc3: rtk: use
scoped device node handling to simplify error paths").

There is only one caller and because of the way that the types work out,
returning negative error codes is not a problem.  They will be treated
as greater than USB_SPEED_HIGH and ignored as invalid.  So this patch
does not affect run time behavior, it's just a clean up.

Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
---
 drivers/usb/dwc3/dwc3-rtk.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/dwc3/dwc3-rtk.c b/drivers/usb/dwc3/dwc3-rtk.c
index b3db5cd9906e..e9c8b032c72c 100644
--- a/drivers/usb/dwc3/dwc3-rtk.c
+++ b/drivers/usb/dwc3/dwc3-rtk.c
@@ -184,7 +184,7 @@ static enum usb_device_speed __get_dwc3_maximum_speed(struct device_node *np)
 
 	ret = of_property_read_string(dwc3_np, "maximum-speed", &maximum_speed);
 	if (ret < 0)
-		return ret;
+		return USB_SPEED_UNKNOWN;
 
 	ret = match_string(speed_names, ARRAY_SIZE(speed_names), maximum_speed);
 
-- 
2.45.2

On 12/09/2024 10:54, Dan Carpenter wrote:
> The __get_dwc3_maximum_speed() function returns an enum type which, in
> this context here, is basically unsigned int.  On error cases, it's
> supposed to return USB_SPEED_UNKNOWN, but it was accidentally changed to
> return negative error codes in commit f93e96c544ca ("usb: dwc3: rtk: use
> scoped device node handling to simplify error paths").
> 
> There is only one caller and because of the way that the types work out,
> returning negative error codes is not a problem.  They will be treated
> as greater than USB_SPEED_HIGH and ignored as invalid.  So this patch
> does not affect run time behavior, it's just a clean up.
> 
> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>

Fixes: f93e96c544ca ("usb: dwc3: rtk: use scoped device node handling to simplify error paths")
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>


Best regards,
Krzysztof