RE: [PATCH 2/6] usb: gadget: mv_udc: disable HW zlt for ep0

[Peter Chen]

> >
> >
> >
> >
> > > > On Mon, Feb 24, 2014 at 04:03:12PM +0800, Neil Zhang wrote:
> > > > > Hardware zlt will try to send the zero length packet
> > > > > automatically when the data transferd is multiple times of max
> > > > > packet, this will cause issues on Windows.
> > > > > So let's disable HW zlt by default.
> > > >
> > > > Would you have description that what kinds of issue on Windows if
> > > > zlt is is selected?
> > > >
> > >
> > > Enumeration will fail.
> > >
> >
> > What causes enumeration fail, why it does not occur before?
> >
> A unexpected zero packet cause enumeration fail.
> It's not easy that the descriptor is actually 1024 bytes, so not easy to
> be found.
> 

Chipidea bug too? Does it follow ch 8.5.3.2 Variable-length Data Stage, USB 2.0 spec?

Peter

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