PORTS Forum

Ports and Interfaces => USB => Topic started by: Vishal Kewlani on April 12, 2016, 09:10:21 am

Title: USB Host behavior after no response from USB Device in Bulk Out transfer
Post by: Vishal Kewlani on April 12, 2016, 09:10:21 am

Hi all,

Here is the scenario for the problem w.r.t Bulk Out transfer (After both the link partners are in U0),

Host                                                                                                                               Device
DP
                                                                                                                                        ACK TP
DP(DPH Corrupted)
                                                                                                                                        Discards DP as DPH corrupted, (Reference 8.11.3 in USB 3.1 Specification)

Now, as described above, what should the Host do? Should it resend the DP with correct DPH after some time or it should halt the endpoint after the time tHostTransactionTimeout (Reference 8.13) ?

Thanks,
Vishal

Title: Re: USB Host behavior after no response from USB Device in Bulk Out transfer
Post by: Jan Axelson on April 12, 2016, 09:52:09 am

8.13 says to resend in the next service interval:

"If a
timeout occurs, the host shall not perform any
more transactions to the endpoint in the current
service interval. The host shall not halt the
endpoint and shall restart transactions to the
endpoint in the next service interval."