[PATCH v2 2/5] usb: dwc3-generic: Return early when there is no child node

[Marek Vasut]

On 7/16/23 03:05, Jonas Karlman wrote:
> On 2023-07-16 02:58, Marek Vasut wrote:
>> On 7/16/23 01:10, Jonas Karlman wrote:
>>> The current error check for device_find_first_child is not working as
>>> expected, the documentation for device_find_first_child mention:
>>>
>>>     @devp: Returns first child device, or NULL if none
>>>     Return: 0
>>>
>>> Change to return early when there is no child node to avoid any possible
>>> null pointer dereference.
>>>
>>> Signed-off-by: Jonas Karlman <jonas at kwiboo.se>
>>> ---
>>> v2:
>>> - Update commit message
>>>
>>>    drivers/usb/dwc3/dwc3-generic.c | 6 +++---
>>>    1 file changed, 3 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/drivers/usb/dwc3/dwc3-generic.c b/drivers/usb/dwc3/dwc3-generic.c
>>> index 35e4b36a695e..4d5d500aefab 100644
>>> --- a/drivers/usb/dwc3/dwc3-generic.c
>>> +++ b/drivers/usb/dwc3/dwc3-generic.c
>>> @@ -558,9 +558,9 @@ int dwc3_glue_probe(struct udevice *dev)
>>>    			return ret;
>>>    	}
>>>    
>>> -	ret = device_find_first_child(dev, &child);
>>> -	if (ret)
>>> -		return ret;
>>> +	device_find_first_child(dev, &child);
>>> +	if (!child)
>>> +		return 0;
>>
>> What does device_find_first_child() return in your case ? ENODEV or ENOSYS ?
> 
> device_find_first_child always returns 0, same as is documented.
> 
> See https://source.denx.de/u-boot/u-boot/-/blob/master/drivers/core/device.c#L931-941

Ah, I see, thanks for clarifying.

Reviewed-by: Marek Vasut <marex at denx.de>

Could you fix mtu3_plat.c the same way and switch this function to 
return void ? (separate series for these two things please)