On Mon, 2 Jul 2007, jidong xiao wrote:
> Another separate issue,still focus on this piece of code,(inside
> drivers/usb/core/hub.c, hub_configure())
>
> > >
> > > 570 switch (hdev->descriptor.bDeviceProtocol) {
> > > 571 case 0:
> > > 572
On Sunday 01 July 2007, jidong xiao wrote:
>
> Now my concern is, for root hub, here we can see, hcd->driver->flags
> will be used to decide which descriptor will be returned, however,
> what if non-root hub?
Then the hub hardware answers the question -- as I said before.
--
Another separate issue,still focus on this piece of code,(inside
drivers/usb/core/hub.c, hub_configure())
> >
> > 570 switch (hdev->descriptor.bDeviceProtocol) {
> > 571 case 0:
> > 572 break;
> > 573 case 1:
> > 5
Great,thanks Alan and David.
Your answers are exactly what I really needed.
Alan,
According to your implication,I took a look at
rh_call_control(),and finally found such piece of code,I felt this
explains my question clearly.
376 case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
377
Dave already answered some of these questions. Here are my views:
On Sun, 1 Jul 2007, jidong xiao wrote:
> about device descriptor,according to usb spec 2.0,
> 1. A hub returns different descriptors based on whether it is
> operating at high speed or full/low speed.A hub can report three
> diffe
On Sunday 01 July 2007, jidong xiao wrote:
> Take root hub for example, how does the hub itself know whether its
> upstream facing port is connected at high-speed or
> full-speed?
There *IS* no upstream facing port. The upstream link hooks
to a non-USB bus.
> Futhermore, if a host send a GET_D
