Re: Testing endpoint halt support for raw-gadget

[Peter Chen <peter.chen@nxp.com>]

On 20-04-10 11:53:20, Alan Stern wrote:
> On Fri, 10 Apr 2020, Andrey Konovalov wrote:
> 
> > On Fri, Apr 10, 2020 at 2:29 AM Alan Stern <stern@rowland.harvard.edu> wrote:
> 
> > > Have you implemented wedge as well as halt?  Wedge is needed for the
> > > mass-storage protocol; as far as I know it isn't used anywhere else.
> > 
> > No, I didn't know about "wedge" at all :) Looks like the API for it is
> > really simple, just usb_ep_set_wedge(). I'll need to figure out what
> > it is and how it works, and I'll send a patch that adds halt/wedge
> > support then.
> 
> usb_ep_set_wedge(ep) does almost the same thing as 
> usb_ep_set_halt(ep).  The difference is that a Clear-Feature(halt) 
> request from the host will un-halt an endpoint if it is merely halted, 
> but it won't un-halt a wedged endpoint.  (I don't think this is 
> documented anywhere, unfortunately.)

Hi Alan,

It is documented at drivers/usb/gadget/udc/core.c, function
usb_ep_set_wedge.

-- 

Thanks,
Peter Chen