Hi, > -----Original Message----- > From: Peter Chen [mailto:hzpeterchen@xxxxxxxxx] > Sent: Friday, August 12, 2016 4:48 PM > To: Jun Li <jun.li@xxxxxxx> > Cc: Peter Chen <peter.chen@xxxxxxx>; linux-usb@xxxxxxxxxxxxxxx > Subject: Re: [PATCH] usb: chipidea: udc: don't touch DP when controller is > in host mode > > On Thu, Aug 11, 2016 at 06:52:45PM +0800, Li Jun wrote: > > When the controller is configured to be dual role and it's in host > > mode, if bind udc and gadgt driver, those gadget operations will do > > gadget disconnect and finally pull down DP line, which will break host > function. > > > > Signed-off-by: Li Jun <jun.li@xxxxxxx> > > --- > > drivers/usb/chipidea/udc.c | 7 +++++-- > > 1 file changed, 5 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/usb/chipidea/udc.c b/drivers/usb/chipidea/udc.c > > index 761b804..846b77bc 100644 > > --- a/drivers/usb/chipidea/udc.c > > +++ b/drivers/usb/chipidea/udc.c > > @@ -1593,8 +1593,11 @@ static int ci_udc_pullup(struct usb_gadget > > *_gadget, int is_on) { > > struct ci_hdrc *ci = container_of(_gadget, struct ci_hdrc, gadget); > > > > - /* Data+ pullup controlled by OTG state machine in OTG fsm mode */ > > - if (ci_otg_is_fsm_mode(ci)) > > + /* > > + * Data+ pullup controlled by OTG state machine in OTG fsm mode; > > + * and don't touch Data+ in host mode for dual role config. > > + */ > > + if (ci_otg_is_fsm_mode(ci) || ci->role == CI_ROLE_HOST) > > return 0; > > > > pm_runtime_get_sync(&ci->gadget.dev); > > -- > > Would you show me how to reproduce it? I can't reproduce it. > According to your description, the ci->vbus_active is false, > then the pullup operation will NOT do real pull up. A pull *down*(not pull up) will be done when gadget driver load. How to reproduce: 1. Switch to host mode by ID cable + usb device 2. Load a gadget driver, e.g. modprobe g_ether 3. You will see the RS bit is cleared. Li Jun > > -- > > Best Regards, > Peter Chen -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
