RE: [PATCH] usb: gadget: f_fs: report error if excess data received

[Du, Changbin]

> >> thanks Alan Stern and Michal.
> >> Here just have a comment - the buffered data need be dropped when
> the
> >> epfile is closed, because it means the session is terminated.
> >
> > I blame that on sleep deprivation.  Another issue is what to do when
> > endpoint is disabled.  Should the buffer be cleared as soon as the
> > endpoint is disabled?  Or maybe when the endpoint is enabled again?  Or
> > maybe it should never be cleared?
> >
> > If the buffer is cleared when endpoint is disabled, we again silently
> > drop data.  On the other hand, if we donât do that, read() on the
> > endpoint will may succeed even if the configuration is disabled which
> > may be surprising for users.
> 
> tough decision... but seems like clearing the buffer as soon as ep is
> disabled is the way to go.
> 
> --
> Balbi

I agree with Balbi, seems it is not easy to maintain the excess buffer... I was to
implement it at the beginning but I am not confident everything is done correctly.