RE: [PATCH v10 2/7] usb: mux: add generic code for dual role port mux

Jun Li
2016-06-07T07:08:31Z

Hi Baolu

> -----Original Message-----
> From: Lu Baolu [mailto:baolu.lu@linux.intel.com]
> Sent: Tuesday, June 07, 2016 2:27 PM
> To: Jun Li <jun.li@nxp.com>; Roger Quadros <rogerq@ti.com>; Peter Chen
> <hzpeterchen@gmail.com>
> Cc: felipe.balbi@linux.intel.com; Mathias Nyman <mathias.nyman@intel.com>;
> Greg Kroah-Hartman <gregkh@linuxfoundation.org>; Lee Jones
> <lee.jones@linaro.org>; Heikki Krogerus <heikki.krogerus@linux.intel.com>;
> Liam Girdwood <lgirdwood@gmail.com>; Mark Brown <broonie@kernel.org>;
> linux-usb@vger.kernel.org; linux-kernel@vger.kernel.org
> Subject: Re: [PATCH v10 2/7] usb: mux: add generic code for dual role port
> mux
>
> Hi Jun,
>
> On 06/07/2016 11:03 AM, Jun Li wrote:
> > Hi Roger
> >
> >>
> >> For Mux devices implementing dual-role, the mux device driver _must_
> >> use OTG/dual-role core API so that a common ABI is presented to user
> >> space for OTG/dual-role.
> > That's the only point we have concern, do dual role switch through
> > OTG/dual-role core, not do it by itself.
>
> That really depends on how do you define "dual role". Can you please
> provide an unambiguous definition of "dual role" used in OTG/dual-role
> framework?

Host and peripheral.

>
> Best regards,
> Lu Baolu
>
> >
> >> I haven't yet looked at the mux framework but if we take care of the
> >> above point then we are not introducing any redundancy.
> >>
> > Roger, actually this is my worry on OTG core: those dual role switch
> > users just tends to do it simply by itself(straightforward and easy),
> > not through the OTG core(some complicated in first look), this is just
> > an example for us to convince people to select a better
> > way:)
> >
> > Li Jun
> >