[PATCH 1/6] usb: Return -ENOSYS when system call is not available

[Marek Vasut]

On 3/21/21 5:12 AM, Simon Glass wrote:
> Hi Marek,
> 
> On Sun, 21 Mar 2021 at 17:09, Marek Vasut <marex at denx.de> wrote:
>>
>> On 3/21/21 4:18 AM, Simon Glass wrote:
>>> Update usb_gadget_release() to use -ENOSYS, which is the correct error
>>> code for U-Boot.
>>
>> It would be good if you could explain _why_ this change is required. Why
>> is ENOSYS the correct return value ? It is not clear from the patch
>> description, sorry.
> 
> That is the value used throughout driver model, so it is a convention.
> As per the cover letter and one on the patches, people are not sure
> which one to use, because -ENOTSUPP has crept in in a few places.

I agree with Tom, this needs to be documented first, then the document 
should be agreed upon, and only then should these fixes follow.