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

[Jonas Karlman]

On 2023-07-16 03:19, Marek Vasut wrote:
> 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)

Sorry, not sure when I would have time for that, currently way too much
ongoing in my pipeline :-)

Regards,
Jonas