hi Alan:
2014-04-09 6:58 GMT+08:00 Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>:
> On Tue, 8 Apr 2014, vichy wrote:
>
>> > That's a different bit. USB_PORT_FEAT_C_RESET isn't the same as
>> > USB_PORT_FEAT_RESET.
>> what I am curious is,
>> if port reset bit will clear to 0 within 2ms, why we still need to
>> clear_port_feature with USB_PORT_FEAT_C_RESET
>> (clear Port reset )
>> >
>> >> if (hub_is_superspeed(hub->hdev)) {
>> >> clear_port_feature(hub->hdev, port1,
>> >> USB_PORT_FEAT_C_BH_PORT_RESET);
>> >> clear_port_feature(hub->hdev, port1,
>> >> USB_PORT_FEAT_C_PORT_LINK_STATE);
>> >> clear_port_feature(hub->hdev, port1,
>> >> USB_PORT_FEAT_C_CONNECTION);
>> >> }
>
> Because if we leave these bits set, the hub will send messages on its
> interrupt endpoint telling us that these bits need to be cleared.
I got what makes me confused.
The USB_PORT_FEAT_C_RESET only work for non-root hub.
appreciate your kind help,
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