Re: [PATCH] usb: cdns3: gadget: Don't manage pullups

From: Peter Chen
Date: Tue Oct 29 2019 - 21:15:23 EST


On 19-10-29 11:37:31, Roger Quadros wrote:
>
>
> On 29/10/2019 05:12, Peter Chen wrote:
> > On 19-10-25 12:59:17, Roger Quadros wrote:
> > > Peter,
> > >
> > > On 25/10/2019 06:13, Peter Chen wrote:
> > > > On 19-10-23 09:17:45, Pawel Laszczak wrote:
> > > > > Hi,
> > > > >
> > > > > Reviewed-by: Pawel Laszczak <pawell@xxxxxxxxxxx>
> > > >
> > > > Hi Roger & Pawel,
> > > >
> > > > Assume gadget function has already enabled, if you switch host mode
> > > > to device mode, with your changes, where the device mode will be enabled
> > > > again?
> > >
> > > When it switches from device mode to host the UDC is removed. When we switch
> > > back from host to device mode the UDC is added, so,
> > >
> > > usb_add_gadget_udc_release()-> check_pending_gadget_drivers()->
> > > udc_bind_to_driver()->usb_udc_connect_control()->usb_gadget_connect()->
> > > gadget->ops->pullup()
> >
> > Thanks. I have another question how you decide when to store UDC name
> > to /sys/kernel/config/usb_gadget/g1/UDC? Do you have a user daemon program
> > to monitor VBUS or external connector? At host mode, the store operation
> > will fail due to there is NO UDC.
> >
>
> Yes, user space needs to monitor /sys/class/usb_role/6000000.usb-role-switch/role
>
> When it becomes "device" the UDC is available and it can prepare to configure
> the UDC.
>
> Could you please give your Ack for this patch if it is OK? Thanks.
>

Acked-by: Peter Chen <peter.chen@xxxxxxx>

--

Thanks,
Peter Chen