Re: [PATCH] usb: udc: add gadget state kobject uevent

[Felipe Balbi <balbi@ti.com>]

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On Wed, Jul 17, 2013 at 09:04:54PM +0800, Rong Wang wrote:
> Hi Felipe,
> 
> On Wed, Jul 17, 2013 at 3:57 PM, Felipe Balbi <balbi@ti.com> wrote:
> > Hi,
> >
> > On Mon, Jul 15, 2013 at 11:31:17PM -0700, Greg KH wrote:
> >> > The question is since we default GADGET, so the g_mass_storage.ko is
> >> > installed early but connecting to a host PC
> >> > is randomly, But the udev has no idea when a host PC connects our device.
> >> >
> >> > So we consider it's reasonable to let the udev know the GADGET device state.
> >> > Is there any alternative to our question?
> >>
> >> I thought we already export events for gadget device states, have you
> >> looked for them?  I can't dig through the code at the moment, but this
> >> seems like a pretty common issue...
> >>
> >> Felipe, any ideas?
> >
> > we already expose that in sysfs. IIRC udev can act on sysfs changes,
> > no ?
> 
> I do not know if udev can polling sysfs file content change. I'll study this.
> 
> But the change is triggered by calling usb_gadget_set_state, and I find
> composite framework do not call this. Then we should do this common work
> in every udc driver?

yes. Only the UDC driver knows when the controller is moving among those
states.

-- 
balbi

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