Hi, David,
When you start the HNP, did you call the function -- usb_bus_start_enum?
As you know, usb_bus_start_enum will reset the port. and according to
OHCI port, if reset the port, USB_PORT_STAT_ENABLE will be set. so
when we go into the following code,
if ((portstatus & USB_PORT_STAT_ENABLE) && (
type != HUB_RESUME ||
!(portstatus & USB_PORT_STAT_CONNECTION) ||
!udev ||
udev->state == USB_STATE_NOTATTACHED)) {
clear_port_feature(hdev, port1, USB_PORT_FEAT_ENABLE)
portstatus &= ~USB_PORT_STAT_ENABLE;
}
the condition will be satisified, so we will call the
clear_port_feature(hdev, port1, USB_PORT_FEAT_ENABLE). Then it will
cause the port disconnected. Then OTG statemachine will be changed
from B_HOST to B_PERIPHERAL.
Regards
Yong
2009/4/17 David Brownell <david-b@xxxxxxxxxxx>:
> On Thursday 16 April 2009, Eric Miao wrote:
>> > But I'm not entirely sure this patch is correct. Does this affect
>> > some of the OTG conformance tests? I've certainly observed HNP
>> > to proceed through b_host enumerating an a_peripheral (after the
>> > role switch) with the current code.
>> >
>> > Of course, the fact that I've seen it work *could* be caused by
>> > bugs in the drivers I was working with.
>> >
>>
>> David,
>>
>> Could you let me know which exact platform and OTG driver you've
>> used when you observed it was working?
>
> The musb_hdrc driver, in OTG mode. Working on two different
> flavors of TI silicon (OMAP3, DaVinci) talking to each other
> with Gadget Zero set up as the HNP test device ... so that as
> soon as the a_host sees that b_device, it initiates HNP.
>
> (That's *with* the benefit of the HNP fixes now in Greg's
> 2.6.31 merge queue.)
>
> One test I want to get back to is having *both* nodes be that
> HNP test device. One wants to be sure it doesn't keep looping
> in HNP, switching roles forever. ;)
>
>
> And also, back in the 2.6.10 days ... OMAP 1611 H2 platforms,
> talking both to each other and to the full speed OTG test
> harness. I don't think that's been tested at all recently,
> and so I expect some level of bitrot has set in. That was
> the original test platform for all this OTG code, of course.
>
> - Dave
>
>
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