[PATCH] usb: cdns3: fix cdns3_bind() to avoid returning error and probe parent

[Marek Vasut]

On 3/1/26 2:02 AM, Siddharth Vadapalli wrote:

>>> diff --git a/drivers/usb/cdns3/core.c b/drivers/usb/cdns3/core.c
>>> index 10bc4cabed4..a775567b3bc 100644
>>> --- a/drivers/usb/cdns3/core.c
>>> +++ b/drivers/usb/cdns3/core.c
>>> @@ -461,9 +461,18 @@ int cdns3_bind(struct udevice *parent)
>>>       /* Use VBUS Valid to determine role */
>>>       if (dr_mode == USB_DR_MODE_OTG) {
>>> +        /*
>>> +         * Since we perform register accesses in cdns3_get_otg_mode(),
>>> +         * we need to ensure that the parent has been probed and that
>>> +         * the USB Controller is powered ON.
>>> +         */
>>> +        ret = device_probe(parent);
>>> +        if (ret)
>>> +            goto fail;
>>> +
>>>           ret = cdns3_get_otg_mode(parent, &dr_mode);
>>>           if (ret < 0)
>>> -            return ret;
>>> +            goto fail;
>>>       }
>> Can you instead move this logic into driver .probe() ? Then you 
>> wouldn't need the device_probe() hackage.
>>
> 
> There are two users of cdns3_bind() which have registered their 
> own .bind() callback as cdns3_bind():
> 1. cdns3-starfive.c driver
> 2. cdns3-ti.c driver
> Since .bind() is called before .probe()

.bind callback is meant to BIND the driver instance (to a DT node), it 
is not meant to initialize the hardware. .probe callback is meant to 
initialize the hardware. This is fundamental part of the U-Boot DM lazy 
initialization scheme. If something does initialize hardware in .bind, 
then it is very likely wrong.

> , and, since cdns3_bind() is also 
> the .bind() callback of the above drivers, device_probe() has to be 
> added here itself. Moreover, it is only due to the register accesses 
> being performed by the recently introduced cdns3_get_otg_mode() function 
> that we need the USB Controller to be powered ON at this stage.
So, can we fix this so the HW initialization won't be happening in bind, 
but instead in .probe ?