Hi Greg,
Thanks for your suggestion. We are trying to move to kernel-3.10.
But I still have a question about EHCI which actually abstracts our question.
I have noticed Figure 4-14. Host Controller Queue Head Traversal State Machine
in EHCI spec.
Simplified:
execute transaction ---------------
| |
!Active | |
| | Active (we encounter
this case, and it keeps but host controller actually receive data to
overlay and ACK device)
\|/ |
write back qTD |
| |
| |
\|/ |
follow QH horizontal pointer <-|
The left path is normal case, but we encounter the right path and it
keeps that state.
So I wander under which case would the host controller leave Active
'1' and do not
write the overlay back to qTD, but actually it receives date and ACK the device.
and the total bytes to transfer in the overlay actually decrease.
Could you comment on this case? I've not found a clear answer in the spec yet.
On Wed, Jul 3, 2013 at 2:18 AM, Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> On Tue, Jul 02, 2013 at 01:58:29PM +0800, Rong Wang wrote:
>> Hi all,
>>
>> We are developing an embedded product which can connect ipod and play
>> its contents.
>> But for some particular reason we need to force the ipod to connect at
>> full-speed.
>>
>> Chipidea usb ip did not provide an companion HC, but it provide
>> embedded TT to handle full-speed. And we found that there a patch
>> provided by Alan Stern.
>>
>> link to the patch: http://markmail.org/message/v2ro33mydllddvtk
>>
>> We apply the patch (we use linux-2.6.38.8) and have successfully
>> forced the controller running at full-speed only.
>
> That's a patch from 2009, for an old, and obsolete kernel version that
> us in the community really can't support at all, sorry.
>
> Do you have the same problems on the latest kernel version? If you are
> stuck at this older version, please contact the company providing it to
> you for support, as they are the best ones that can do this.
>
> sorry,
>
> greg k-h
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