Re: urb status EOVERFLOW

Hi Alan,

On 7/5/07, Alan Stern <[email protected]> wrote:
> On Wed, 4 Jul 2007, Felipe Balbi wrote:
>
> > > If the device firmware has gone crazy, reset the device, then port.
> > > This is what HID does, for example, because in it's illegal for
> > > HID devices to bunch reports together.
> >
> > and what about ending the session and starting all over again???
> > seems to me that we don't know what's causing the babble in some
> > cases... so the only way out is ending the session in the usb host
> > controller itself.
>
> Resetting the device (or its port -- I can't quite tell exactly what
> Pete meant above) effectively _does_ start a new session.
>
> However with some devices, the only way to truly reset them is to
> unplug their power cable.  Not much the kernel can do then.

Some usb controllers (at least the one I've being working on) has a
Session Bit in some register. When you clear that bit you force the
controller to completely end the session. Is something like a software
disconnect.

When you write 1 again to that bit, the controller re-enumerates
everything attached.

>
> Alan Stern
>
>


-- 
Best Regards,

Felipe Balbi
[email protected]

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