Re: [PATCH 4/5] usb: xhci: dbc: Add a dbc raw driver to provide a raw interface on DbC

[Greg KH <gregkh@linuxfoundation.org>]

On Mon, Jun 10, 2019 at 04:53:51PM +0300, Mathias Nyman wrote:
> On 7.6.2019 17.21, Greg KH wrote:
> > On Fri, Jun 07, 2019 at 12:03:05PM +0530, Prabhat Chand Pandey wrote:
> > > From: Abhilash K V <abhilash.k.v@intel.com>
> > > 
> > > This patch provides a raw device interface on xhci Debug capability.
> > 
> > What is a "raw device"?
> > 
> > > This abstracts dbc functionality to user space inorder to facilitate
> > > various frameworks to utilize xhci debug capability.
> > 
> > I do not understand this sentance at all.  Please provide a lot more
> > information.
> > 
> > > It helps to render the target as an usb debug class device on host and
> > > establish an usb connection by providing two bulk endpoints.
> > 
> > provide bulk endpoints where?  To send data where?  This is very
> > confusing and does not make any sense to me...
> > 
> > 
> > > 
> > > [don't dynamically allocate tiny space for name only -Mathias]
> > > Signed-off-by: Rajaram Regupathy <rajaram.regupathy@intel.com>
> > > Signed-off-by: Prabhat Chand Pandey <prabhat.chand.pandey@intel.com>
> > > Signed-off-by: Abhilash K V <abhilash.k.v@intel.com>
> > > Acked-by: Mathias Nyman <mathias.nyman@linux.intel.com>
> > > ---
> ...
> > 
> > So you have a new char device, with a undocumented and unknown format of
> > data flowing across it to the device.  How in the world are we supposed
> > to use this thing?  Where is it documented?  What does it do?  How can
> > you use it?
> > 
> > I don't mean to be so harsh here, but come on people, this stuff needs a
> > lot more background documentation, information, and explaination as to
> > exactly why in the world we need any of this, and what it even does!
> > 
> > Also, you need to fix the code, it doesn't work as pointed out in a few
> > places :)
> > 
> 
> Thanks for going through this.
> It's now clear this is far from ready.
> I need to re-evaluate my position on this, not just the code and the documentation,
> but the usefulness of it all.

What is this even supposed to be used for?  What is the application for
it?  I couldn't determine that at all, what am I missing?

thanks,

greg k-h