Re: testusb: epipe errors on test 9 and 10

[Thinh Nguyen <Thinh.Nguyen@synopsys.com>]

On Tue, Dec 02, 2025, Alan Stern wrote:
> On Tue, Dec 02, 2025 at 04:23:13AM +0000, Thinh Nguyen wrote:
> > On Mon, Dec 01, 2025, Alan Stern wrote:
> > > Are we talking about the same thing?  Clear-Feature is different from 
> > > Get-Interface-Status.
> > > 
> > 
> > Ah... I just saw the subject line testusb -EPIPE and assumed that it's
> > related to ClearFeature(halt_ep)..
> > 
> > The Get-Interface-Status should be hand-off and handled by gzero right?
> > The gadget driver knows about the status of the interface, not UDC
> > driver.
> 
> For USB-2 devices, Get-Interface-Status is always supposed to return two 
> bytes of 0.  For USB-3 devices, it returns information about Function 
> Remote Wakeup and Function Remote Wakeup Capable, which is handled 
> already by the composite core.
> 
> So for SuperSpeed and above, the request should be delegated.  For high 
> speed and below, it could be done either way.  (dummy-hcd makes the 
> opposite mistake; it always returns zeros for Get-Interface-Status and 
> never delegates.)
> 
> If you think it's best always to delegate the request then composite.c 
> needs to be changed; it should handle the reply for non-SuperSpeed 
> connections.  A simple change; I can do it.  What do you prefer?
> 

Right this change is simple. I think it's probably easier to delegate
and enforce this in the composite library instead of auditing all the
UDC drivers.

Thanks!
Thinh