Re: [PATCH] usb: chipidea: udc: clear vbus_active flag in udc_stop

[Jiada Wang]

Hi

On 10/20/2015 03:01 PM, Peter Chen wrote:
> On Tue, Oct 20, 2015 at 11:29:18AM +0900, Jiada Wang wrote:
> > Currently in udc_stop, if vbus_active flag is true, all USB activities
> > will be stopped, but vbus_active flag is still left to be true,
> > this causes issue, when afterwards driver tries to connect gadget
> > device to host, But due to the uncleared vbus_active, some necessary
> > setup steps are skipped.
> >
> > This patch clears vbus_active flag in udc_stop callback.
> >
> > Signed-off-by: Jiada Wang <jiada_wang@xxxxxxxxxx>
> > ---
> >   drivers/usb/chipidea/udc.c | 1 +
> >   1 file changed, 1 insertion(+)
> >
> > diff --git a/drivers/usb/chipidea/udc.c b/drivers/usb/chipidea/udc.c
> > index 8223fe7..b9ac228 100644
> > --- a/drivers/usb/chipidea/udc.c
> > +++ b/drivers/usb/chipidea/udc.c
> > @@ -1762,6 +1762,7 @@ static int ci_udc_stop(struct usb_gadget *gadget)
> >   	spin_lock_irqsave(&ci->lock, flags);
> >
> >   	if (ci->vbus_active) {
> > +		ci->vbus_active = 0;
> >   		hw_device_state(ci, 0);
> >   		if (ci->platdata->notify_event)
> >   			ci->platdata->notify_event(ci,
> > --
> > 2.4.5
>
> This flag will be handled by vbus interrupt, would you please explain
> more what problem you have met?
the actual issue I had is,
build kernel with USB_OTG_FSM enabled,
keep usb cable plugged,
load/unload USB gadget module (for example I tried g_zero or g_serial),
after unload gadget module once, then the status of vbus_active is not
correct,
this causes host machine failed to detect gadget device when later
gadget device module is loaded again.


Thanks,
Jiada
>
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