On Wed, Oct 19, 2011 at 05:09:22PM +0530, Gupta, Ajay Kumar wrote:
> Hi,
> > > Hi,
> > >> On Thu, Oct 13, 2011 at 12:50:55PM +0530, Gupta, Ajay Kumar wrote:
> > >>> We are facing an issue in AM335x based custom board which has two
> > musb
> > >>> port.
> > >>>
> > >>> a) musb0 ID pin is floating and have micro-B plug receptacle
> > >>> connector. [DEVICE ONLY]
> > >>> b) musb1 ID pin is grounded and have standard-A plug receptacle
> > >>> connector. [HOST ONLY]
> > >>>
> > >>> We are using udc-core in linux v3.1-rc8 kernel. This kernel only
> > >>> provides option for selecting gadget driver for first instance only
> > as
> > >>> builtin.
> > >>
> > >> why don't you mark all gadget drivers as modules ? I do that all the
> > >> time:
> > >
> > > This wouldn't help if we want to use musb1 (host only) port during
> > bootup so that root file system on a pen drive connected to it can be
> > mounted.
> >
> > I don't think it hurts that use case as the host driver is enabled by
> > the platform data without other sections of the kernel having it hard-
> > coded to a port.
>
> My comment was w.r.t current musb driver which needs gadget module to be
> Inserted and why we can't have gadget as modules (as suggested by Felipe
> above) for host only ports in such use case.
you misunderstood me. I said that host-only ports, should not need
anything. See the switch below.
> If we have modified musb driver where host only port can be initialized
> then there is no discussion needed for gadget module or builtin
> for such ports.
isn't this what I suggested before ??
> > >> You can add runtime checks based on platform_data. Something like:
> > >>
> > >> switch (pdata->mode) {
> > >> case MUSB_HOST:
> > >> start_host();
> > >> break;
> > >> case MUSB_PERIPHERAL:
> > >> start_gadget();
> > >> break;
> > >> case MUSB_OTG:
> > >> start_gadget()
> > >> start_host();
> > >> break;
> > >> default:
> > >> error();
> > >> }
> > >>
> > >> which means that for a port which is host-only, it won't require a
> > >> gadget driver and for a port which is gadget-only, it won't start
> > host
> > >> stack.
> > >
> > > If so then how about the menuconfig option for gadget driver for such
> > host only port? Shouldn't the gadget driver option be unavailable for such
> > ports?
you can't change menuconfig for a particular port on a controller.
--
balbi
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