Re: testusb: epipe errors on test 9 and 10

[Angelo Dureghello <angelo@kernel-space.org>]

Hi Alan,

On 11/28/25 17:10, Alan Stern wrote:
> On Fri, Nov 28, 2025 at 10:20:25AM -0500, Alan Stern wrote:
>> On Fri, Nov 28, 2025 at 03:20:35PM +0100, Angelo Dureghello wrote:
>>> Hi Alan,
>>>
>>> thanks a lot,
>>>
>>> On 11/28/25 04:23, Alan Stern wrote:
>>>> I think this is the expected behavior; g_zero does not support
>>>> Get-Interface-Status.
>>> ok, good to know. Btw, on this article seems all tests are passing
>>>
>>> https://bootlin.com/blog/test-a-linux-kernel-usb-device-controller-driver-with-testusb/
>>>
>>> but not really clear what what "test must pass" is.
>> It looks like something may have changed between the time when that
>> article was written and now.  I would expect g-zero to support
>> Get-Interface-Status, since it is a standard request.
> This was wrong; I had forgotten that Get-Status requests are mostly
> handled by the UDC driver, not by the gadget drivers.  In your case, I
> guess that's dwc3?
>
> In the current kernel, these requests are handled in
> drivers/usb/dwc3/ep0.c:dwc3_ep0_handle_status().  The problem is that
> this routine doesn't handle Get-Interface-Status requests at all;
> instead it passes them through to the composite core, which doesn't
> handle many of them either.  Other UDC drivers do a better job.
>
> Fixing this should be pretty easy, but I'm not not an expert on dwc3.
> The maintainer, Thinh Nguyen, will know what to do.
Thanks a lot, really, will look this direction so.

> Alan Stern
angelo