USB vendore designations..

[Julian Elischer]

Hans Petter Selasky wrote:

>On Monday 27 December 2004 08:15, Julian Elischer wrote:
>  
>
>>Now, when you do the "doobell trick" as descibed in the spec,
>>there is one little part of it.. that is the catch.
>>
>>The spec says:
>>"Software should first deactivate all active qTDs, wait for the
>>queue head to go inactive, then remove the queue head from
>>the asynchronous list."
>>
>>Note the word "all"
>>
>>Ok, so since we want to remove only SOME of the qTDs from the queue
>>(those corresponding to the aborting command), and we need to read
>>the status word to see which has been completed by whether the
>>active bit is set, and since we are in a race with the hardware
>>to clear the active bit, which of the qTDs, not in the list of
>>qTDs we want to remove, was completed?
>>
>>    
>>
>Maybe the EHCI driver should not reuse the QH's for transfers on the same 
>pipe, but instead like I did, have one QH for each transfer, insterted into 
>the asynchronous schedule after that the last QH has been removed?
>

It's an interesting idea..

where did you do this?  In a new driver?

sorry to be stupid but qa pointer would be good?

s this the driver in _usb I think I saw from you earlier?


It has the good point of being "clean"
It has the bad point of only allowing one transaction per interrupt cycle.

>
>Yours
>--HPS
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